Technical Field
[0001] This application relates generally to microelectronics fabrication and materials
for microelectronics fabrication.
Background
[0002] The increase in computing power and spatial densities in semiconductor-based devices
and energy efficiency of the same allow for ever more efficient and small microelectronic
sensors, processors and other machines. These have found wide use in mobile and wireless
applications and other industrial, military, medical and consumer products.
[0003] Even though computing energy efficiency is improving over time, the total amount
of energy used by computers of all types is on the rise. Hence, there is a need for
even greater energy efficiency.
Summary
[0004] Example embodiments described herein have innovative features, no single one of which
is indispensable or solely responsible for their desirable attributes. The following
description and drawings set forth certain illustrative implementations of the disclosure
in detail, which are indicative of several exemplary ways in which the various principles
of the disclosure may be carried out. The illustrative examples, however, are not
exhaustive of the many possible embodiments of the disclosure. Without limiting the
scope of the claims, some of the advantageous features will now be summarized. Other
objects, advantages and novel features of the disclosure will be set forth in the
following detailed description of the disclosure when considered in conjunction with
the drawings, which are intended to illustrate, not limit, the invention.
[0005] An aspect of the invention is directed to a method for manufacturing a ferromagnetic-dielectric
composite material, comprising: placing patterned ferromagnetic layer regions, in
a patterning substrate assembly, in physical contact with a second dielectric layer,
the second dielectric layer in a receiving substrate assembly, wherein: the patterning
substrate assembly includes a patterning substrate, a first carrier release layer,
a first dielectric layer, and the patterned ferromagnetic layer regions, the first
carrier release layer disposed between the first dielectric layer and the patterning
substrate, the first dielectric layer disposed between the first carrier release layer
and the patterned ferromagnetic layer regions; the receiving substrate assembly includes
a receiving substrate, a second carrier release layer, and the second dielectric layer,
the second carrier release layer disposed between the second dielectric layer and
the receiving substrate. The method further comprises forming a bond between the patterned
ferromagnetic layer regions and the second dielectric layer; releasing the patterning
substrate from the patterning substrate assembly to transfer the patterned ferromagnetic
layer regions and the first dielectric layer from the patterning substrate assembly
to the receiving substrate assembly; and releasing the receiving substrate from the
receiving substrate assembly to form the ferromagnetic-dielectric composite material.
[0006] In one or more embodiments, the method further comprises activating the first carrier
release layer to detach the patterned ferromagnetic layer regions from the patterning
substrate assembly. In one or more embodiments, activating the first carrier release
layer comprises (a) exposing the first carrier release layer to a solvent to at least
partially dissolve the first carrier release layer, (b) exposing the first carrier
release layer to a light source to compromise a physical integrity of the first carrier
release layer, and/or (c) heating the first carrier release layer to compromise the
physical integrity of the first carrier release layer. In one or more embodiments,
activating the second carrier release layer comprises (a) exposing the second carrier
release layer to a solvent to at least partially dissolve the second carrier release
layer, (b) exposing the second carrier release layer to a light source to compromise
a physical integrity of the second carrier release layer, and/or (c) heating the second
carrier release layer to compromise the physical integrity of the second carrier release
layer.
[0007] In one or more embodiments, the method further comprises depositing a lift-off photoresist
on the patterning substrate to form the first carrier release layer. In one or more
embodiments, the method further comprises depositing the first dielectric layer on
the first carrier release layer; defining a first pattern in the first dielectric
layer, the first pattern comprising first dielectric layer regions and holes defined
between neighboring first dielectric layer regions; defining a second pattern in the
first carrier release layer according to the pattern in the first dielectric layer,
the second pattern in the first carrier release layer comprising first carrier release
layer regions and holes defined between neighboring first carrier release layer regions,
wherein the first carrier release layer regions are aligned with the first dielectric
layer regions and the holes between neighboring first carrier release layer regions
are aligned with the holes between neighboring first dielectric layer regions to reveal
exposed patterning substrate regions; and after defining the second pattern, depositing
a ferromagnetic material on the first carrier release layer regions to form first
ferromagnetic layer regions on the second dielectric layer regions and second ferromagnetic
layer regions on the exposed patterning substrate regions, wherein the patterned ferromagnetic
layer regions comprise the first ferromagnetic layer regions such that the first ferromagnetic
layer regions are placed in physical contact with the second dielectric layer in the
receiving substrate assembly. In one or more embodiments, the ferromagnetic material
comprises a soft ferromagnetic material and the method further comprising applying
a bias magnetic field to set an easy axis of magnetization of the soft ferromagnetic
material. In one or more embodiments, releasing the patterning substrate from the
patterning substrate assembly transfers the first ferromagnetic layer regions and
the first dielectric layer regions from the patterning substrate assembly to the receiving
substrate assembly.
[0008] In one or more embodiments, the method further comprises after releasing the patterning
substrate from the patterning substrate assembly, depositing a third dielectric layer
on the patterning substrate assembly to fill the holes between neighboring first dielectric
layer regions and respective holes between neighboring first ferromagnetic layer regions.
In one or more embodiments, the method further comprises spin-coating the third dielectric
layer on the patterning substrate assembly.
[0009] In one or more embodiments, the method further comprises depositing the first dielectric
layer on the first carrier release layer; depositing a ferromagnetic layer on the
first dielectric layer; and defining a pattern in the ferromagnetic layer, the pattern
comprising the patterned ferromagnetic layer regions and holes between neighboring
ferromagnetic layer regions.
[0010] In one or more embodiments, defining a pattern in the ferromagnetic layer comprises:
depositing photoresist layer on the ferromagnetic layer; defining a pattern in the
photoresist layer to form photoresist layer regions and holes between neighboring
photoresist layer regions, the holes revealing exposed ferromagnetic layer regions;
and removing the exposed ferromagnetic layer regions.
[0011] In one or more embodiments, the first carrier release layer comprises a lift-off
photoresist layer, and the method further comprises removing an edge region of the
first dielectric layer to reveal exposed lift-off photoresist layer regions at an
edge region of the lift-off photoresist layer.
[0012] In one or more embodiments, forming the bond between the patterned ferromagnetic
layer regions and the second dielectric layer comprises heating and applying pressure
to the patterned ferromagnetic layer regions and the second dielectric layer. In one
or more embodiments, holes are defined between neighboring patterned ferromagnetic
layer regions, and the method further comprises while heating the patterned ferromagnetic
layer regions and the second dielectric layer, re-flowing the first dielectric layer
and/or the second dielectric layer to fill the holes.
[0013] In one or more embodiments, the method further comprises depositing the first carrier
release layer on the patterning substrate; depositing the first dielectric layer on
the first carrier release layer; depositing a photoresist layer on the first dielectric
layer; defining a pattern in the photoresist layer to form photoresist layer regions
and holes defined between neighboring photoresist layer regions, the holes revealing
exposed first dielectric layer regions; depositing a ferromagnetic layer on the patterning
substrate assembly, the ferromagnetic layer comprising first ferromagnetic layer regions
disposed on the photoresist layer regions and second ferromagnetic layer regions disposed
on the exposed first dielectric layer regions; and exposing the remaining patterned
photoresist layer regions to a solvent to remove the remaining patterned photoresist
layer regions, thereby removing the first ferromagnetic layer regions, wherein the
patterned ferromagnetic layer regions comprise the second ferromagnetic layer regions
such that the second ferromagnetic layer regions are placed in physical contact with
the second dielectric layer in the receiving substrate assembly.
[0014] In one or more embodiments, forming the bond between the patterned ferromagnetic
layer regions and the second dielectric layer comprises heating and applying pressure
to the second ferromagnetic layer regions and the second dielectric layer, holes are
defined between neighboring second ferromagnetic layer regions, and the method further
comprises while heating the second ferromagnetic layer regions and the second dielectric
layer, re-flowing the first dielectric layer and/or the second dielectric layer to
fill the holes.
[0015] In one or more embodiments, the method further comprises depositing the first carrier
release layer on the patterning substrate; depositing the first dielectric layer on
the first carrier release layer; depositing a lift-off photoresist layer on the first
dielectric layer; depositing a photoresist layer on the lift-off photoresist layer;
defining a first pattern in the photoresist layer to form photoresist layer regions
and holes defined between neighboring photoresist layer regions; defining a second
pattern in the lift-off resist layer according to the first pattern, the second pattern
forming lift-off resist layer regions and holes defined between neighboring lift-off
resist layer regions, wherein the lift-off resist layer regions are aligned with the
photoresist layer regions and the holes between neighboring lift-off resist layer
regions are aligned with the between neighboring photoresist layer regions to reveal
exposed first dielectric layer regions; depositing a ferromagnetic layer on the patterning
substrate assembly, the ferromagnetic layer comprising first ferromagnetic layer regions
disposed on the photoresist layer regions and second ferromagnetic layer regions disposed
on the exposed first dielectric layer regions; and exposing the lift-off resist layer
regions to a solvent to remove the lift-off resist layer regions, thereby removing
the photoresist layer regions and the first ferromagnetic layer regions, wherein the
patterned ferromagnetic layer regions comprise the second ferromagnetic layer regions
such that the second ferromagnetic layer regions are placed in physical contact with
the second dielectric layer in the receiving substrate assembly.
[0016] In one or more embodiments, the method further comprises placing the receiving substrate
assembly on a support apparatus that comprises: a body having a planar center region
and an edge region, the planar region configured to support a back surface of the
receiving substrate; a support ring disposed on the edge region of the body; a plurality
of bolts that releasably engage the edge region of the body and the support ring;
a double-sided polyimide tape disposed along the support ring; a polyimide, polymer,
or ceramic film layer disposed on the receiving substrate and the double-sided polyimide
tape; and a dielectric layer disposed on and covering the polyimide, polymer, or ceramic
film layer.
[0017] Another aspect of the invention is directed to a method for manufacturing a ferromagnetic-dielectric
composite material, comprising: (a) placing first patterned ferromagnetic layer regions,
in a first patterning substrate assembly in a plurality of patterning assemblies,
in physical contact with a second receiving dielectric layer, the second receiving
dielectric layer in a receiving substrate assembly, wherein: each patterning substrate
assembly includes a respective patterning substrate, a first respective carrier release
layer, a first respective dielectric layer, and respective patterned ferromagnetic
layer regions, the first respective carrier release layer disposed between the first
respective dielectric layer and the respective patterning substrate, the first respective
dielectric layer disposed between the first respective carrier release layer and the
respective patterned ferromagnetic layer regions, and the receiving substrate assembly
includes a receiving substrate, a second carrier release layer, and the second receiving
dielectric layer, the second carrier release layer disposed between the second receiving
dielectric layer and the receiving substrate. The method further comprises (b) forming
a bond between the first patterned ferromagnetic layer regions and the second receiving
dielectric layer; (c) releasing the first patterning substrate from the patterning
substrate assembly to transfer the first patterned ferromagnetic layer regions and
a first dielectric layer from the first patterning substrate assembly to the receiving
substrate assembly; (d) placing second patterned ferromagnetic layer regions, in a
second patterning substrate assembly in the plurality of patterning assemblies, in
physical contact with the first dielectric layer in the receiving substrate assembly;
(e) forming a bond between the second patterned ferromagnetic layer regions and the
first dielectric layer; (f) releasing a second patterning substrate from the second
patterning substrate assembly to transfer the second patterned ferromagnetic layer
regions and the second dielectric layer from the first patterning substrate assembly
to the receiving substrate assembly; and (g) releasing the receiving substrate from
the receiving substrate assembly to form the ferromagnetic-dielectric composite material.
[0018] In one or more embodiments, the method further comprises repeating steps (d)-(f),
prior to step (g), to form a stack of the second patterned ferromagnetic layer regions.
[0019] Another aspect of the invention is directed to a method for manufacturing a ferromagnetic-dielectric
composite material. The method includes depositing a carrier release layer on a substrate;
defining a pattern in the carrier release layer to form patterned carrier release
layer, the patterned carrier release layer defining exposed substrate regions; depositing
a first insulator layer on the patterned carrier release layer and the exposed substrate
regions to form first and second isolated insulator layer regions, the first isolated
insulator layer regions disposed on the patterned carrier release layer, each second
isolated insulator layer region disposed on a respective exposed substrate region;
depositing a ferromagnetic layer on the first insulator layer to form first and second
isolated ferromagnetic layer regions, each first isolated ferromagnetic layer region
disposed on a respective first isolated insulator layer region, each second ferromagnetic
layer region disposed on a respective second isolated insulator layer region; depositing
a second insulator layer on the ferromagnetic layer to form a third and fourth isolated
insulator layer regions, each third isolated insulator layer region disposed on a
respective first isolated ferromagnetic layer region, each fourth isolated insulator
layer region disposed on a respective second isolated ferromagnetic layer region;
exposing the carrier release layer to a solvent to release a plurality of ferromagnetic
film platelets, each ferromagnetic film platelet including the respective first isolated
insulator layer region, the respective first isolated ferromagnetic layer region,
and a respective third isolated insulator layer region; desiccating the ferromagnetic
film platelets; adding a binding material to the ferromagnetic film platelets; and
forming a coupon that includes the ferromagnetic film platelets.
[0020] In one or more embodiments, the ferromagnetic film platelets are desiccated before
the binding material is added. In one or more embodiments, the binding material is
in a liquid form when the binding material is added to the ferromagnetic film platelets.
In one or more embodiments, the method further comprises applying a bias magnetic
field to align an easy axis of magnetization of the respective first isolated ferromagnetic
layer region of each ferromagnetic film platelet in a liquid binding material. In
one or more embodiments, the method further comprises curing the liquid binding material
to form a coupon that includes a solid binding material and the ferromagnetic film
platelets, the easy axes of magnetization substantially aligned with each other.
[0021] In one or more embodiments, the ferromagnetic film platelets are desiccated after
the binding material is added to the ferromagnetic film platelets and the solvent.
In one or more embodiments, the method further comprises applying a bias magnetic
field to align an easy axis of magnetization of the respective first isolated ferromagnetic
layer region of each ferromagnetic film platelet in the solvent and the binding material.
In one or more embodiments, desiccating the ferromagnetic film platelets includes:
evaporating the solvent; and curing the binding material, wherein the desiccating
occurs while the easy axes of magnetization are substantially aligned with each other.
Brief Description of the Drawings
[0022] For a fuller understanding of the nature and advantages of the concepts disclosed
herein, reference is made to the detailed description of preferred embodiments and
the accompanying drawings.
Fig. 1 is an example cross-sectional view of a ferromagnetic-dielectric composite
material according to an embodiment.
Fig. 2 is an example cross-sectional view of a ferromagnetic-dielectric composite
material according to another embodiment.
Fig. 3 is a top view of the ferromagnetic polymer composite material illustrated in
Fig. 2.
Fig. 4 is an example cross-sectional view of a ferromagnetic film platelet according
to an alternative embodiment.
Figs. 5A and 5B are example cross-sectional views of a ferromagnetic film platelet
according to alternative embodiments.
Fig. 6 is a flow chart of a method for manufacturing a ferromagnetic-dielectric composite
material according to an embodiment.
Figs. 7A-7L are cross-sectional views of structures formed according to certain steps
of the flow chart illustrated in Fig. 6.
Fig. 8 is a flow chart of a method for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment.
Figs. 9A-9L are cross-sectional views of structures formed according to certain steps
of the flow chart illustrated in Fig. 8.
Fig. 10 is a flow chart of a method for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment.
Figs. 11A-11E are cross-sectional views of structures formed according to certain
steps of the flow chart illustrated in Fig. 10.
Fig. 12 is a flow chart of a method for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment.
Figs. 13A-13M are cross-sectional views of structures formed according to certain
steps of the flow chart illustrated in Fig. 12.
Fig. 14 is a flow chart of a method for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment.
Fig. 15 is a cross-sectional illustration of an apparatus, in a first state, that
can be used to support the receiving substrate during manufacturing.
Fig. 16 is a cross-sectional illustration of the apparatus illustrated in Fig. 15
in a second state.
Fig. 17 is a flow chart of a method for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment.
Figs. 18A-18J are cross-sectional views of structures formed according to certain
steps of the flow chart illustrated in Fig. 17.
Fig. 19 is an example cross-sectional illustration of a multilevel wiring structure
that includes an inductor having a ferromagnetic polymer composite material core according
to an embodiment.
Detailed Description
[0023] A ferromagnetic-dielectric composite material is formed using a patterning substrate
assembly and a receiving substrate assembly. The patterning substrate assembly includes
a patterning substrate onto which one or more ferromagnetic layer(s) have been deposited
and patterned. A releasable layer is disposed between the patterned ferromagnetic
layer(s) and the patterning substrate. The receiving substrate assembly includes a
receiving substrate, a releasable layer disposed on the receiving substrate, and a
dielectric layer disposed on the releasable layer.
[0024] The patterned ferromagnetic layer(s) in the patterning substrate assembly is/are
placed into contact with the dielectric layer in the receiving substrate assembly.
Pressure and/or heat are applied to the patterning and receiving substrate assemblies
to form a bond between the dielectric layer and the patterned ferromagnetic layer
that is in contact with the dielectric layer. After the bond is formed, the releasable
layer in the patterning substrate assembly is activated to detach the patterning substrate,
which transfers the patterned ferromagnetic layer(s) from the patterning substrate
assembly to the receiving substrate assembly. Additional ferromagnetic layer(s) can
be formed and/or transferred to the patterning substrate assembly. A dielectric layer
can be deposited on the transferred ferromagnetic layer(s) to fill in the holes between
the transferred ferromagnetic layer portions/regions. When all ferromagnetic layer(s)
are transferred to the patterning substrate assembly, the releasable layer in the
patterning substrate assembly is activated to detach the receiving substrate, to form
the ferromagnetic-dielectric composite material.
[0025] The releasable layer in the patterning substrate assembly and/or the releasable layer
in the receiving substrate assembly can comprise or consist of a carrier release layer,
a lift-off photoresist layer, or a negative photoresist layer. The releasable layer
can be activated through the application of heat, pressure, and/or force, and/or exposure
to a solvent and/or light energy.
[0026] Fig. 1 is an example cross-sectional view of a ferromagnetic-dielectric composite material
10 according to an embodiment. The material 10 includes a plurality of ferromagnetic
film platelets 100 and a dielectric 110. The arrangement and/or alignment of the platelets
100 with respect to each other can be customized during the manufacturing of the material
10. The number of platelets 100 can also be customized during the manufacturing of
the material 10.
[0027] Each platelet 100 includes one or more ferromagnetic layers 120. When the platelet
100 includes multiple ferromagnetic layers 120, the platelet 100 can include a laminate
structure. A non-ferromagnetic layer, such as an insulator layer, can be disposed
between some or each ferromagnetic layers 120 in the laminate structure.
[0028] The ferromagnetic layer(s) 120 can include cobalt, nickel, and/or iron, and/or a
compound or alloy comprising cobalt, nickel, and/or iron. In one example, the ferromagnetic
layer(s) 120 comprises a soft ferromagnetic material or layer, such as Co
xZr
yTa
1-x-y (CZT) with x and y being about 0.915 and 0.04, respectively. In another example,
the soft ferromagnetic material or layer can comprise CoZrTa-B (or CoZrTaB), CoNiFe,
NiFe, CoFe, and/or CoFeB, or alloys that include any of the foregoing compounds. The
soft ferromagnetic material or layer can have a magnetic coercivity of less than or
equal to about 1 Oe.
[0029] Additionally or alternatively, the ferromagnetic layer(s) 120 can comprise a hard
ferromagnetic material or layer, such as AlNiCo, NdFeB, SmCo, ferrite alloys of Fe
xO
y that include one or more metals such as Ni, Co, Sr, and/or Ba (e.g., cobalt ferrite
(CoFe
2O
4), and/or nickel ferrite (NiFe
2O
4)), and/or alloys that include any of the foregoing materials. The hard ferromagnetic
material can have a remnant magnetization of at least about 0.1 T and/or a magnetic
coercivity of at least about 100 Oe.
[0030] When the ferromagnetic layer(s) 120 include a soft ferromagnetic layer and a hard
ferromagnetic layer, the hard and soft ferromagnetic layers can be magnetically coupled.
For example, the hard ferromagnetic layer can form a permanent magnetic field that
can bias adjacent/neighboring soft ferromagnetic layer(s), which in-turn can enhance
the properties of the biased soft ferromagnetic layer(s).
[0031] The ferromagnetic layer(s) 120 can be magnetically anisotropic such that its easy
axis of magnetization 122 is parallel to the Y axis (e.g., a first axis) and its hard
axis of magnetization 124 is parallel to the X axis (e.g., a second axis that is orthogonal
to the first axis). Alternatively, the easy axis of magnetization 122 can be parallel
to the X axis and the hard axis of magnetization 124 can be parallel to the Y axis.
The easy and hard axes 122, 124 can be permanently or semi-permanently set. The easy
and hard axes 122, 124 are orthogonal to each other within the x-y plane. In addition,
the easy and hard axes 122, 124 are parallel to a plane 140 that passes through and
is parallel to a bottom (or top) side of the respective ferromagnetic layer 120. The
plane 140 is also orthogonal to the Z axis. The easy and/or hard axes 122, 124 of
each platelet 100 can be aligned or substantially aligned (e.g., within about 5°)
with the respective easy and/or hard axes 122, 124 of the other platelets 100. For
example, the easy and/or hard axes of magnetization 122, 124 in a first platelet 100A
are aligned or substantially aligned (e.g., within about 5°) with the easy and/or
hard axes of magnetization 122, 124 in the other platelets 100, such as the easy and/or
hard axes of magnetization 122, 124 in a second platelet 100B.
[0032] The ferromagnetic layer(s) 120 have a thickness that can be measured along or parallel
to the Z axis, which is orthogonal to the plane 140. When a platelet 100 has a different
orientation with respect to a coordinate system, the thickness of the ferromagnetic
layer(s) 120 can be measured with respect to another axis that is orthogonal to the
plane 140. The thickness of the ferromagnetic layer 120 and/or platelet 100 can be
in a range of about 100 nm to about 10 µm, including about 500 nm, about 1 µm, about
3 µm, about 5 µm, about 7 µm, about 9 µm, and any thickness or thickness range between
any two of the foregoing thicknesses. The thickness of ferromagnetic layer 120 and/or
platelet 100 can be measured along or parallel to the Z axis or another axis that
is orthogonal to the plane 140. As used herein, "about" means plus or minus 10% of
the relevant value.
[0033] The length and width of each platelet 100 can be measured along or parallel to the
X axis and the Y axis, respectively. When a platelet 100 has a different orientation
with respect to a coordinate system, the length and width can be measured with respect
to first and second axes that are parallel to the plane 140 where the first and second
axes are orthogonal to each other and to the axis used to measure the thickness of
the corresponding platelet 100. Each platelet 100 can have a length in a range of
about 1 µm to about 200 µm, including about 50 µm, about 100 µm, about 150 µm, and
any length or length range between any two of the foregoing lengths. In addition,
each platelet 100 can have a width in a range of about 1 µm to about
200 µm, including about 50 µm, about 100 µm, about 150 µm, and any width or width
range between any two of the foregoing widths. The length and width of a platelet
100 can be the same or different. The length and width of the ferromagnetic layer
120 in a given platelet 100 are the same as the length and width, respectively, of
that platelet 100. The ratio of the thickness of the magnetic platelet 100 to the
longer of width or length, which can be referred to as a cross-sectional aspect ratio,
is preferably 1:10 or greater (e.g., 1:20, 1:100, or another ratio). This aspect of
the invention attenuates eddy currents, which would otherwise form in the magnetic
platelet in the presence of an AC magnetic field. Eddy currents in the platelet would
have larger amplitude (and thus larger energy loss) if the platelet were to have a
cross-sectional aspect ratio closer to 1:1.
[0034] In a preferred embodiment, the platelets 100 are identical or substantially identical
to each other. For example, the platelets 100 can comprise the same film layers (e.g.,
ferromagnetic layer(s) 120), materials, and dimensions. In another embodiment, the
platelets 100 can have different film layers, materials, and/or dimensions. In one
example, the platelets 100 include a first group of platelets having a first thickness
and a second group of platelets having a second thickness where the first and second
thicknesses are different. Thus, one group of platelets has a relatively large thickness
and the other group has a relatively small thickness. In another example, the platelets
100 include a first group of platelets having a first length and/or width and a second
group of platelets having a second length and/or width where the first and second
lengths and/or widths are different. Thus, one group of platelets has a relatively
large length and/or width and the other group has a relatively small length and/or
width.
[0035] As illustrated in Fig. 1, the platelets 100 are arranged in rows 150 and columns
160. Alternatively, the platelets 100 in neighboring rows 150A, 150B can be positionally
offset from each other to increase the number of platelets 100 that can be included
in the material 10, as illustrated in
Fig. 2. For example, the platelets 100 in a first group of rows 150A, 150C can be aligned
in a first group of columns, such as column 160A, and the platelets 100 in a second
group of rows 150B, 150D can be aligned in a second group of columns, such as column
160B.
[0036] In some embodiments, the platelets 100 can have a top-view shape as an ellipse 300
and/or a disk 310, for example as illustrated in
Fig. 3 which is a top view of ferromagnetic polymer composite material 10 according to the
embodiment illustrated in Fig. 2. The platelets 100 with the cross-sectional shape
of ellipse 300 can have a three-dimensional shape of an elliptical cylinder. The platelets
with the cross-sectional shape of a disk 310 can have a three-dimensional shape of
a cylinder (e.g., a circular cylinder). The platelets 100 preferably have the same
cross-sectional shape and/or three-dimensional shape which can allow for efficient
packing of the platelets 100 in the dielectric 110. The ferromagnetic polymer composite
material 10 can comprise a range of about 40% to about 99% by volume of the platelets
100 and a range of about 1% to about 60% by volume of the dielectric 110. In a preferred
embodiment, the ferromagnetic polymer composite material 10 comprises about 75% to
about 95% by volume of the platelets 100 and about 5% to about 25% by volume of the
dielectric 110.
[0037] The platelets 100 can have a high relative magnetic permeability and/or a low magnetic
coercivity. For example, the platelets 100 can have a relative magnetic permeability
of about 50 to about 2,000 and/or a coercivity of less than or equal to about 1 Oe
(e.g., about 0 to about 1 Oe) along the hard axis of magnetization 124.
[0038] The dielectric 110 can comprise an epoxy, a synthetic resin, acrylonitrile butadiene
styrene (ABS), nitrocellulose, polyimide, polybenzoxazole (PBO), benzocyclobutene,
divinylsiloxane-bis-benzocyclobutene, polytetrafluoroethylene (PTFE), polysiloxane,
polydimthylsiloxane (PDMS), polymethyl-methacylate (PMMA), parylene, an aromatic polymer,
and/or a photo-imageable polymer (e.g., a photoresist). In some embodiments, the dielectric
110 can comprise a spin-on dielectric or a spin-on photoresist, which can be cured
after or during deposition. In an example, the dielectric 110 can comprise a bisphenol
A novolac epoxy, such as SU-8, which can function as a photoresist.
[0039] The material 10 can have a high relative magnetic permeability and/or a low magnetic
coercivity. The material 10 can have a relative magnetic permeability that is approximately
equal to the volume percentage of platelets 100 in the material 10 multiplied by the
relative magnetic permeability of the platelets 100. For example, when the material
10 comprises 75% platelets by volume, the relative magnetic permeability of the material
10 is approximately equal to 75% multiplied by the relative magnetic permeability
of the platelets 100. The magnetic coercivity of the material 10 can be approximately
equal to the magnetic coercivity of the platelets 100.
[0040] Fig. 4 is an example cross-sectional view of a ferromagnetic film platelet 400 according
to an alternative embodiment. For illustration purposes, the cross section in Fig.
4 is orthogonal to the cross section illustrated in Figs. 1 and 2. In this embodiment,
the ferromagnetic layer(s) 120 include a soft ferromagnetic layer 421 and a hard ferromagnetic
layer 422 that are magnetically coupled to each other. A spacer or insulator layer
can optionally be disposed between the soft and hard ferromagnetic layers 421, 422.
The spacer or insulator layer can comprise the same material or a different material
than the dielectric 110. The hard ferromagnetic layer 422 can have a magnetic coercivity
of at least about 100 Oe and/or a remnant magnetization of at least about 0.1 T. The
soft ferromagnetic layer 421 can have a magnetic coercivity of less than or equal
to about 1 Oe.
[0041] The hard ferromagnetic layer 422 is magnetically anisotropic such that its easy axis
of magnetization 425 is parallel to the Y axis. In addition, the soft ferromagnetic
layer 421 is magnetically anisotropic such that its easy axis of magnetization 428
is parallel to the Y axis. As such, the easy axis of magnetization 425 of the hard
ferromagnetic layer 422 is parallel to (or substantially parallel to) the easy axis
of magnetization 428 of the soft ferromagnetic layer 421.
[0042] The hard ferromagnetic layer 422 is magnetized to produce a bias magnetic field.
The in-plane bias magnetic field flux 440, from the bias magnetic field, through the
hard ferromagnetic layer 422 is in a first direction (e.g., from right to left as
indicated by the arrows in Fig. 4) that is parallel to the easy axis of magnetization
425 of the hard ferromagnetic layer 422. The bias magnetic field flux 440 through
the hard ferromagnetic layer 422 forms a closed bias magnetic field loop by passing
through the neighboring soft ferromagnetic layer 421. The bias magnetic flux 440 through
the soft ferromagnetic layer 421 is in a second direction (e.g., from left to right)
that is opposite (e.g., antiparallel) to the first direction. The second direction
is parallel to (or substantially parallel to) the easy axis of magnetization 428 of
the soft ferromagnetic layer 421.
[0043] The cross-sectional thickness of the soft and hard ferromagnetic layers 421, 422
can be related to their saturation magnetizations. For example, the ratio of the cross-sectional
thickness of the soft ferromagnetic layer 421 to the cross-sectional thickness of
the hard ferromagnetic layer 422 can be equal to or about equal to

where
MS_soft is the saturation magnetization of the soft ferromagnetic layer 421 and
MS_hard is the saturation magnetization of each hard ferromagnetic layer 422. Thus, all or
substantially all of the bias magnetic field flux 440 can form a closed bias magnetic
field loop, as discussed above. In some embodiments, the ratio of the cross-sectional
thickness of the soft ferromagnetic layer 421 to the cross-sectional thickness of
the hard ferromagnetic layer 422 is greater than or equal to about 10 (e.g., about
10 to about 1,000, about 10 to about 500, or about 10 to about 100). The cross-sectional
thickness of the soft and hard ferromagnetic layer 421, 422 can be measured with respect
to the Z axis in Fig. 4.
[0044] The material 10 can include platelets 400 instead of or in addition to platelets
100. The cross-sectional and three-dimensional shapes of platelet 400 can be the same
as cross-sectional and three-dimensional shapes of platelet 100.
[0045] Fig. 5A is an example cross-sectional view of a ferromagnetic film platelet 500 according
to an alternative embodiment. The platelet 500 can be used in place of or in addition
to the platelet 100 and/or platelet 400 in the material 10. The platelet 500 includes
a plurality of non-ferromagnetic layers 510, and a plurality of ferromagnetic layers
520.
[0046] Each ferromagnetic layer 520 can be the same as ferromagnetic layer 120. The ferromagnetic
layers 520 can have the same thicknesses, different thicknesses, or a combination
thereof. The thickness of each ferromagnetic layer can be measured along or with respect
to an axis 545 that is orthogonal to a plane 540 that passes through and is parallel
to the bottom surface 535 of platelet 500. The axis 545 can be the same as the Z axis
or can be parallel to the Z axis. Each ferromagnetic layer 520 can have the same thickness
as ferromagnetic layer 120.
[0047] The platelet 500 can have a cross-sectional aspect ratio that is the same as the
cross-sectional aspect ratio of platelet 100.
[0048] One, some, or all ferromagnetic layers 520 can be magnetically anisotropic such that
its/their easy axis of magnetization 522 is parallel to the Y axis and its/their hard
axis of magnetization 524 is parallel to the X axis. Alternatively, the easy axis
of magnetization 522 can be parallel to the X axis and the hard axis of magnetization
524 can be parallel to the Y axis. The easy and hard axes 522, 524 can be permanently
or semi-permanently set. The easy and hard axes 522, 524 are orthogonal to each other
within the X-Y plane. In addition, the easy and hard axes 522, 524 are parallel to
plane 540. The easy and hard axes 522, 524 of each ferromagnetic layer 520 can be
aligned or substantially aligned (e.g., within 5°) with the respective easy and hard
axes 522, 524 of the other ferromagnetic layers 520.
[0049] Each non-ferromagnetic layer 510 is disposed between a neighboring pair 550 of ferromagnetic
layers 520. Each non-ferromagnetic layer 510 can function as an electrical insulator
layer and/or a diffusion barrier (e.g., with respect to the neighboring ferromagnetic
layers). Each non-ferromagnetic layer 510 can comprise the same material or a different
material than dielectric 110. In some embodiments, each ferromagnetic layer 510 can
comprise aluminum, chromium, cobalt, silicon, tantalum, titanium, silicon, and/or
zirconium. In some embodiments, each non-ferromagnetic layer 510 can comprise an alloy
or compound that includes aluminum, chromium, cobalt, silicon, tantalum, titanium,
silicon, and/or zirconium. For example, each non-ferromagnetic layer 510 can comprise
a compound that includes (a) oxygen and/or nitrogen and (b) aluminum, chromium, cobalt,
silicon, tantalum, titanium, silicon, and/or zirconium. Specific examples of diffusion
barriers can comprise tantalum, chromium, and/or aluminum. The non-ferromagnetic layers
510 can comprise the same or different materials.
[0050] The non-ferromagnetic layers 510 can have the same thicknesses, different thicknesses,
or a combination thereof. Each non-ferromagnetic layer 510 can have a thickness of
about 2 nm to about 200 nm, including about 10 nm, about 25 nm, about 50 nm, about
75 nm, about 100 nm, about 125 nm, about 150 nm, about 175 nm, and any thickness or
thickness range between any two of the foregoing thicknesses. The thickness of each
non-ferromagnetic layer 510 can be measured along or with respect to axis 545.
[0051] In some embodiments, one, some, or all of the non-ferromagnetic layers 510 can be
formed by heating the respective ferromagnetic layer(s) 520 in an oxygen environment
to form a native oxide layer (e.g., a native oxide of the ferromagnetic layer(s) 520.
[0052] The cross-sectional and three-dimensional shapes of platelet 500 can be the same
as cross-sectional and three-dimensional shapes of platelet 100. In addition, the
overall or total thickness of platelet 500 can be in a range of about 200 nm to about
15 µm. The thickness of each platelet 500 can be measured along axis 545.
[0053] The length and width of platelet 500 can be measured along or parallel to the X axis
and the Y axis, respectively. The length and width of platelet 500 can also be measured
with respect to first and second axes that are parallel to the plane 540 where the
first and second axes are orthogonal to each other and to axis 545. The length and
width of platelet 500 can be the same as the length and width, respectively, of platelet
100. The lengths and widths of the non-ferromagnetic layers 510 and ferromagnetic
layers 520 are the same as the length and width, respectively, of platelet 500.
[0054] The platelet 500 can have a high magnetic permeability and/or a low magnetic coercivity.
The relative magnetic permeability and/or the magnetic coercivity of platelet 500
can be the same as the relative magnetic permeability and/or the magnetic coercivity
of platelet 100, respectively.
[0055] Ferromagnetic layers 520 can be soft magnetic layers or hard magnetic layers, and
a platelet 500 can include both soft and hard ferromagnetic layers. The hard ferromagnetic
layer(s) form a permanent magnetic field that can bias adjacent/neighboring soft ferromagnetic
layer(s), which in-turn can enhance the properties of the biased soft ferromagnetic
layer(s). In addition, the hard ferromagnetic layer(s) increase the remanence magnetization
of the platelet, which improves the ability to align the platelet to an external magnetic
field.
[0056] Fig. 5B is an example cross-sectional view of a ferromagnetic film platelet 500 according
to an alternative embodiment. For illustration purposes, the cross section in Fig.
5B is orthogonal to the cross section illustrated in Fig. 5A. In this embodiment,
each ferromagnetic layer 520 includes a soft ferromagnetic layer 5021 and a hard ferromagnetic
layer 5022 that are magnetically coupled to each other. A spacer or insulator layer
can optionally be disposed between the soft and hard ferromagnetic layers 5021, 5022
in each ferromagnetic layer 520. The spacer or insulator layer can comprise the same
material as the dielectric 110. A non-ferromagnetic layer 510 is disposed between
adjacent ferromagnetic layers 520. The hard ferromagnetic layer 5022 is magnetically
anisotropic such that its easy axis of magnetization 5025 is parallel to the Y axis.
In addition, the soft ferromagnetic layer 5021 is magnetically anisotropic such that
its easy axis of magnetization 522 is parallel to the Y axis. As such, the easy axis
of magnetization 5025 of the hard ferromagnetic layer 5022 is parallel to the easy
axis of magnetization 522 of the soft ferromagnetic layer 5021.
[0057] The hard ferromagnetic layer 5022 is magnetized to produce a bias magnetic field.
The in-plane bias magnetic field flux 5040, from the bias magnetic field, through
the hard ferromagnetic layer 5022 is in a first direction (e.g., from right to left
as indicated by the arrows in Fig. 5B) that is parallel to the easy axis of magnetization
5025 of the hard ferromagnetic layer 5022. The bias magnetic field flux 5040 through
the hard ferromagnetic layer 5022 forms a closed bias magnetic field loop by passing
through the neighboring soft ferromagnetic layer 5021. The bias magnetic flux 5040
through the soft ferromagnetic layer 5021 is in a second direction (e.g., from left
to right) that is opposite (e.g., antiparallel) to the first direction. The second
direction is parallel to the easy axis of magnetization 522 of the soft ferromagnetic
layer 5021.
[0058] The cross-sectional thickness of the soft and hard ferromagnetic layers 5021, 5022
can be related to their saturation magnetizations. For example, the ratio of the cross-sectional
thickness of the soft ferromagnetic layer 5021 to the cross-sectional thickness of
the hard ferromagnetic layer 5022 can be equal to or about equal to

where
MS_soft is the saturation magnetization of the soft ferromagnetic layer 5021 and
MS_hard is the saturation magnetization of each hard ferromagnetic layer 5022. Thus, all
or substantially all of the bias magnetic field flux 5040 can form a closed bias magnetic
field loop, as discussed above. In some embodiments, the ratio of the cross-sectional
thickness of the soft ferromagnetic layer 5021 to the cross-sectional thickness of
the hard ferromagnetic layer 5022 is greater than or equal to 10 (e.g., 10 to 1,000,
10 to 500, or 10 to 100). The cross-sectional thickness of the soft and hard ferromagnetic
layers 5021, 5022 can be measured with respect to the axis 545.
[0059] The soft and/or hard ferromagnetic layers 5021, 5022 can be the same as soft and/or
hard ferromagnetic layers 421, 422, respectively.
[0060] Fig. 6 is a flow chart of a method 60 for manufacturing a ferromagnetic-dielectric composite
material according to an embodiment. Method 60 can be used to manufacture material
10.
[0061] In step 600, a carrier release layer and an insulator or dielectric layer (in general,
dielectric layer) are sequentially deposited on a patterning substrate (e.g., a first
substrate). The carrier release layer is deposited on the patterning substrate and
the dielectric layer is deposited on the carrier release layer. In some embodiments,
the dielectric layer is optional.
[0062] An example cross-sectional view of a patterning substrate assembly 70 that includes
a patterning substrate 700, a carrier release layer 710, and a dielectric layer 720
formed according to step 600 is illustrated in
Fig. 7A.
[0063] The patterning substrate 700 can comprise silicon, quartz, glass (e.g., silicon dioxide),
or a ceramic. The patterning substrate 700 can be optically transparent to one or
more wavelengths of light.
[0064] The carrier release layer 710 comprises a material that can form a temporary bond
to the receiving substrate 700. The material can include laminations to provide films
having different properties. The carrier release layer 710 can be activated to release
the temporary bond by exposing the carrier release layer 710 to a solvent, exposing
the carrier release layer 710 to light, heating the carrier release layer 710, and/or
applying pressure or force to the carrier release layer 710. An example of a carrier
release film that can be released by exposure to light is 3M
™ OneFilm WSS Semiconductor Temporary Bonding Film Series, which can be released by
ultraviolet and/or infrared light (e.g., laser). When the carrier release film is
released by exposure to certain wavelengths of light, the patterning substrate 700
can be optically transparent to some or all of those wavelengths of light. An example
of a carrier release film that can be released by applying a force is a double-sided
polyimide tape. An example of a carrier release film that can be released by exposure
to a solvent is a lift-off resist.
[0065] The dielectric layer 720 can comprise or consist of an electrically-insulating polymer
such as PMMA, polyimide, and/or a photoresist such as SU-8. In some embodiments, the
dielectric layer 720 is optional.
[0066] In step 610, a pattern is defined in the carrier release layer and the dielectric
layer. For example, the dielectric layer can be patterned through photolithography
and the patterned dielectric layer can be used to remove (e.g., etch) the underlying
carrier release layer. The patterning substrate assembly can be heated to a range
of about 100°C to about 300°C for about 5 minutes to about 50 minutes during this
step.
[0067] Fig. 7B is an example cross-sectional view of the patterning substrate assembly 70 having
a pattern 730 formed according to step 610. The pattern 730 is first defined in the
dielectric layer 720 to form isolated dielectric layer regions 722 and voids 724 between
adjacent or neighboring isolated dielectric layer regions 722. The pattern 730 is
then applied to the carrier release layer 710 by removing (e.g., etching) the exposed
carrier release layer 710 beneath the voids 724. The pattern 730 applied to the carrier
release layer 710 forms isolated carrier release layer regions 712 and voids 714 between
adjacent or neighboring isolated carrier release layer regions 712. As such, the voids
714 are aligned with the voids 724 and the isolated carrier release layer regions
712 are aligned with the isolated dielectric layer regions 722. The aligned voids
714, 724 define exposed patterning substrate regions 702.
[0068] In step 620, one or more ferromagnetic layer(s) is/are deposited on the patterning
substrate assembly formed in step 610. When more than one ferromagnetic layer is deposited,
a non-ferromagnetic layer, such as an insulator layer, can be deposited between some
or all neighboring ferromagnetic layers.
[0069] Fig. 7C is an example cross-sectional view of the patterning substrate assembly 70 having
an example ferromagnetic layer 740 deposited thereon. The ferromagnetic layer 740
is deposited and formed on the isolated dielectric layer regions 722 and the exposed
patterning substrate regions 702. The portions of the ferromagnetic layer 740 deposited
on the isolated dielectric layer regions 722 form first isolated ferromagnetic layer
regions 742. The portions of the ferromagnetic layer 740 deposited on the exposed
patterning substrate regions 702 form second isolated ferromagnetic layer regions
744. The first and second isolated ferromagnetic layer regions 742, 744 are formed
and/or defined according to the pattern 730.
[0070] In optional step 630, a bias magnetic field is applied during or after the ferromagnetic
deposition step 620. The bias magnetic field can permanently or semi-permanently set
the easy axis of magnetization of the ferromagnetic layer in a direction parallel
to the bias magnetic field. Permanently or semi-permanently setting the direction
of the easy axis of magnetization can permanently or semi-permanently set the direction
of the hard axis of magnetization in a direction orthogonal to the easy axis of magnetization
in the major plane of the ferromagnetic layer. When the bias magnetic field is applied
after the ferromagnetic deposition step 620, the bias magnetic field can be applied
while heating or annealing the patterning substrate assembly 70 in the form of a magnetic
anneal at a temperature of about 200°C to about 340°C with a magnetic field of about
0.1 Tesla to about 1.5 Tesla and a duration of about 10 to about 200 minutes. The
structure can be heated or annealed in an oven or can be placed near a heat source.
The bias magnetic field can be a DC magnetic field. The magnetic field applied during
deposition of the ferromagnetic layer(s) can have the same magnitude and duration
as the magnetic field applied during the magnetic anneal.
[0071] Fig. 7D is an example cross-sectional view of the patterning substrate assembly 70 including
the ferromagnetic layer 740 while applying an optional bias magnetic field 745. The
easy axis of magnetization 751 of the ferromagnetic layer 740 is permanently or semi-permanently
aligned with the axis of the bias magnetic field 745. Aligning the easy axis of magnetization
751 with the axis of the bias magnetic field induces the hard axis of magnetization
752 of the ferromagnetic layer 740 to be aligned in a direction orthogonal to the
easy axis of magnetization 751 within the major plane of the ferromagnetic layer 740.
For example, the major plane of the ferromagnetic layer 740 is parallel to the top
surface 701 of the patterning substrate 700.
[0072] In step 640 (via placeholder A), a carrier release layer and a dielectric layer are
sequentially deposited on a receiving substrate (e.g., a second substrate). The carrier
release layer is deposited on the receiving substrate and the dielectric layer is
deposited on the carrier release layer. The carrier release layer and/or the dielectric
layer deposited in step 630 can be the same or different than the carrier release
layer and/or the dielectric layer, respectively, deposited in step 600.
[0073] An example cross-sectional view of a receiving substrate assembly 72 that includes
a receiving substrate 760, a carrier release layer 770, and a dielectric layer 780
formed according to step 640 is illustrated in
Fig. 7E. The receiving substrate 760, the carrier release layer 770, and the dielectric layer
780 can be the same as or different than the patterning substrate 700, the carrier
release layer 710, and the dielectric layer 720, respectively.
[0074] In step 650, the patterned ferromagnetic layer on the patterning substrate assembly
is placed in contact (e.g., direct physical contact) with the exposed dielectric layer
on the receiving substrate assembly.
[0075] Fig. 7F is an example cross-sectional view of the structure formed in step 650. The patterning
substrate assembly 70 in Fig. 7F has been flipped upside down compared to the patterning
substrate assembly 70 in Figs. 7A-7D. After the patterning substrate assembly 70 is
rotated vertically by 180 degrees, the patterning substrate assembly 70 and the receiving
substrate assembly 72 are moved towards each other so that the first isolated ferromagnetic
layer regions 742 in the patterning substrate assembly 70 are in contact (e.g., direct
physical contact) with the dielectric layer 780 in the receiving substrate assembly
72.
[0076] In step 660, a bond is formed between the patterned ferromagnetic layer on the patterning
substrate assembly and the dielectric layer on the receiving substrate assembly. The
bond can be formed by applying pressure to the patterning and receiving substrate
assemblies 70, 72 and/or by heating the patterning and receiving substrate assemblies
70, 72. For example, pressure in the range of about 0.1 MPa to about 30 MPa, including
about 1MPa, about 10 MPa, about 15 MPa, about 20 MPa, about 25 MPa, or another pressure
between any two of the foregoing pressures can be applied to the patterning and receiving
substrate assemblies 70, 72. In another embodiment, a different pressure can be applied.
The pressure can be applied for about 1 minute to about 90 minutes, including about
2 minutes, about 5 minutes, about 15 minutes, about 30 minutes, about 40 minutes,
about 50 minutes, about 60 minutes, about 70 minutes, about 80 minutes, or another
time or time range between any two of the foregoing times. The patterning and receiving
substrate assemblies 70, 72 can be heated during, after, or before the pressure is
applied. In an embodiment, the patterning and receiving substrate assemblies 70, 72
can be heated to a range of about 100°C to about 300°C, including about 150°C, about
200°C, about 250°C, or another temperature or temperature range between any two of
the foregoing times. An optional vacuum (e.g., less than or equal to about 10 µTorr)
can be applied during step 660 to remove or reduce the number of voids at the bonding
interface.
[0077] In some embodiments, dielectric layers 720 and/or 780 can be replaced with a native
oxide of the ferromagnetic layer 740. The native oxide can be formed by heating the
ferromagnetic layer 740 in an oxygen-rich environment while the ferromagnetic layer
740 is on the patterning substrate assembly 70 or on the receiving substrate assembly
72.
[0078] In step 670, the patterning substrate is detached from the patterning substrate assembly.
The patterning substrate is detached by activating the carrier release layer in the
patterning substrate assembly, such as by exposing the carrier release layer to a
solvent, exposing the carrier release layer to light, heating the carrier release
layer, and/or applying pressure or force to the carrier release layer. Activating
the carrier release layer can cause its physical integrity to decrease, which can
reduce the bond or adhesion between the carrier release layer and the patterning substrate
and/or between the carrier release layer and the dielectric layer.
[0079] Fig. 7G is an example cross-sectional view of the structure formed in step 670. In this example
cross-sectional view, the carrier release layer 710 has been removed by exposing the
carrier release layer 710 to a solvent. As a result, the remainder of the patterning
substrate assembly 70 (i.e., the patterning substrate 700, the second isolated ferromagnetic
layer regions 744, and any remaining portions of the carrier release layer 710) is
detached from the receiving substrate assembly 72. When the patterning substrate assembly
70 is detached from the receiving substrate assembly 72, the dielectric layer 720
and the ferromagnetic layer(s) 740 are transferred from the patterning substrate assembly
70 to the receiving substrate assembly 72.
[0080] In optional step 680 (via placeholder B), a dielectric layer is deposited on the
receiving substrate assembly after the patterning substrate is detached from the receiving
substrate assembly. The dielectric layer 790 can fill in the gaps, holes, or voids
724 between neighboring isolated dielectric layer regions 722 and the gaps, holes,
or voids 746 between neighboring first isolated ferromagnetic layer regions 742, as
illustrated in
Fig. 7H. The dielectric layer 790 can be the same or different than the dielectric layer 720
and/or the dielectric layer 780. In one example, the dielectric layer 790 can be deposited
by spin-on application, which can also planarize the dielectric layer 790. The spin-on
dielectric can be cured after or during deposition. Alternatively, the dielectric
layer 790 can be planarized in a separate processing step. The dielectric layer 790
can optionally be deposited on the dielectric layer 720. The dielectric layer 790
can improve the mechanical strength and/or stability of the receiving substrate assembly
72 and/or can improve adhesion or bonding to an additional ferromagnetic layer.
[0081] In another embodiment, the dielectric layer 790 can reflow during step 660 to fill
the holes 746.
[0082] If additional ferromagnetic layer(s) are to be formed on or transferred to the receiving
substrate assembly (i.e., step 690=yes), the method 60 proceeds to step 692. In step
692, one or more additional ferromagnetic layer(s) are formed on a new patterning
substrate (e.g., in a new patterning substrate assembly) in the same manner as in
steps 600-630. The ferromagnetic layer(s) formed on the new patterning substrate assembly
are then bonded and transferred to the receiving substate assembly in the same manner
as in steps 650-670. Alternatively, the new patterning substrate can be prefabricated
in which case step 692 only includes bonding and transferring the additional ferromagnetic
layer(s) to the receiving substate assembly, which can be performed in the same manner
as steps 650-670. In some embodiments, a total of 2 to 100 ferromagnetic layer(s)
or another number of ferromagnetic layer(s) can be formed or transferred to the receiving
substrate assembly.
[0083] In some embodiments, the first isolated ferromagnetic layer regions 742 in the new
patterning substrate assembly can be placed directly over the first isolated ferromagnetic
layer regions 742 in the receiving substrate assembly or they can be offset with respect
to each other, which can increase the packing density of ferromagnetic layers on the
receiving substrate assembly. One or more alignment structures can be formed on the
receiving substrate assembly and/or on the patterning substrate assembly, which can
be used by optics systems to align or offset the first isolated ferromagnetic layer
regions 742 with respect to each other.
[0084] Fig. 7I is an example cross-sectional view of the structure formed in step 692 where the
optional dielectric layer 790 was not deposited in optional step 680.
[0085] In optional step 694, a dielectric layer is deposited on the receiving substrate
assembly after the new patterning substrate is detached from the receiving substrate
assembly to fill the gaps in the receiving substrate assembly. Optional step 694 can
be performed in the same manner as optional step 680.
[0086] After optional step 694, the method returns to step 690. This process can proceed
in a loop with steps 692 and 694 repeated until the desired number of ferromagnetic
layer(s) are formed on the receiving substrate assembly.
[0087] If no additional ferromagnetic layer(s) are to be formed on the receiving substrate
assembly (i.e., step 690=no), the method 60 proceeds to optional step 696 (via placeholder
C). In optional step 696, a dielectric layer is deposited on the receiving substrate
assembly to fill any voids, holes, or gaps in the receiving substrate assembly.
Fig. 7J is an example cross-sectional view of the structure formed in step 696 where the
dielectric layer 790 fill the gaps, holes, or voids 792 between neighboring isolated
structures 794 (Fig. 7I) of dielectric and ferromagnetic layers.
[0088] In step 698, the receiving substrate is detached from the receiving substrate assembly.
The receiving substrate is detached by activating the carrier release layer in the
receiving substrate assembly, such as by exposing the carrier release layer to a solvent,
exposing the carrier release layer to light, heating the carrier release layer, and/or
applying pressure or force to the carrier release layer. Activating the carrier release
layer can cause its physical integrity to decrease, which can reduce the bond or adhesion
between the carrier release layer and the receiving substrate and/or between the carrier
release layer and the neighboring dielectric layer.
[0089] Fig. 7K is an example cross-sectional view of the structure formed in step 698 where the
receiving substrate assembly 72 had the same structure as in Fig. 7J prior to detaching
the receiving substrate 760 from the receiving substrate assembly 72. After the receiving
substrate 760 is detached and removed, a ferromagnetic-dielectric composite material
74 is formed, as illustrated in
Fig. 7L. The ferromagnetic-dielectric composite material 74 includes dielectric layers and/or
dielectric regions 780, 720, 722, and 794, and first isolated ferromagnetic layer
regions 742. Depending on how the ferromagnetic-dielectric composite material 74 is
formed, the ferromagnetic-dielectric composite material 74 can include additional
or fewer rows of first isolated ferromagnetic layer regions 742. The easy axes of
magnetization 751 can be aligned in the first isolated ferromagnetic layer regions
742. In addition, the hard axes of magnetization 752 can be aligned in the first isolated
ferromagnetic layer regions 742. The ferromagnetic-dielectric composite material 74
can be the same as ferromagnetic-dielectric composite material 10.
[0090] In an alternative embodiment, only a carrier release layer is deposited in step 600
and a dielectric layer (e.g., dielectric layer 720) is not deposited in step 600.
In some embodiments, multiple first isolated ferromagnetic layer regions 742 can be
deposited on the patterning substrate assembly with a non-ferromagnetic layer (e.g.,
non-ferromagnetic layer 510) disposed between neighboring first isolated ferromagnetic
layer regions 742. The first isolated ferromagnetic layer regions 742 are released
from the patterning substrate assembly (i.e., without being transferred to the receiving
substrate assembly) by exposing the carrier release layer 710 to a solvent. The combined
solvent and loose platelets (e.g., first isolated ferromagnetic layer regions 742)
are dispensed into a mold and the solvent is then removed (e.g., by evaporation).
During this solvent removal process, a biasing magnetic field is applied to the mold
to align the platelets and set the easy axis of the composite. Prior to the solvent
removal a thermoplastic binding agent such as divinylsiloxane-bis-benzocyclobutene
(DVS-bis-BCB, or BCB), such as bis-benzocyclobutene (BCB), or PMMA, or an epoxy may
be added to the solvent to disperse it throughout the coupon, or these same bonding
materials may be added to the platelets following desiccation to bond them into a
coupon. Following desiccation and the addition of a bonding agent, the coupon can
be compressed to a controlled thickness through the application of a temperature between
about 90°C and about 400°C (including any value or range between these temperatures),
and a pressure between about 1MPa and about 1GPa (including any value or range between
these pressures), depending on the glass temperature of the binding agent and the
desired final sample thickness.
[0091] Fig. 8 is a flow chart of a method 80 for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment. Method 80 can be used to manufacture material
10.
[0092] In step 800, a carrier release layer and a dielectric layer are sequentially deposited
on a patterning substrate. The carrier release layer is deposited on the patterning
substrate and the dielectric layer is deposited on the carrier release layer. Step
800 can be the same as step 600.
[0093] An example cross-sectional view of a patterning substrate assembly 90 that includes
a patterning substrate 900, a carrier release layer 910, and a dielectric layer 920
formed according to step 600 is illustrated in
Fig. 9A. The patterning substrate 900, the carrier release layer 910, and the dielectric layer
920 can be the same as the patterning substrate 700, the carrier release layer 710,
and/or the dielectric layer 720, respectively.
[0094] In step 810, a photoresist layer is deposited on the dielectric layer. An example
cross-sectional view of the patterning substrate assembly 90 including the patterned
photoresist layer 930 is illustrated in
Fig. 9B. The photoresist layer can include a negative photoresist or a positive photoresist.
[0095] In step 820, a negative pattern is defined in the photoresist layer. The pattern
can be defined through photolithography and development of the photoresist layer.
[0096] Fig. 9C is an example cross-sectional view of the patterning substrate assembly 90 formed
in step 820. The photoresist layer 930 is formed into a pattern 940 of isolated photoresist
layer regions 932 that have not been exposed to light during photolithography. Gaps
or holes 934 are formed between adjacent or neighboring isolated photoresist layer
regions 932. The gaps or holes 934 reveal exposed dielectric layer regions 922.
[0097] In step 830, one or more ferromagnetic layer(s) is/are deposited onto the patterned
photoresist layer. When more than one ferromagnetic layer is deposited, a non-ferromagnetic
layer, such as an insulator layer, can be deposited between some or all neighboring
ferromagnetic layers. Step 830 can be the same as step 620.
[0098] Fig. 9D is an example cross-sectional view of the patterning substrate assembly 90, including
the ferromagnetic layer(s) 950, formed in step 830. The ferromagnetic layer(s) 950
include ferromagnetic layer(s) regions 952 that are deposited on the isolated photoresist
layer regions 932 and ferromagnetic layer(s) regions 954 that are deposited on the
exposed dielectric layer regions 922 in the gaps or holes 934. As such, the ferromagnetic
layer(s) 950 conform to the pattern 940.
[0099] In optional step 832, a bias magnetic field is applied during or after the ferromagnetic
deposition step 830 to set the easy axis or magnetization in a direction parallel
to the bias magnetic field, which can set the hard axis of magnetization in a direction
orthogonal to the bias magnetic field in the major plane of the ferromagnetic layer.
Step 832 can be the same as step 630. A cross-sectional illustration of this step
would appear the same or similar to as structure 70 in Fig. 7D.
[0100] In step 834 (via placeholder A), the remaining photoresist layer is exposed to a
solvent to remove the remaining photoresist layer. Exposing the remaining photoresist
layer to the solvent causes the ferromagnetic layer(s) 952 deposited on the isolated
negative photoresist layer regions 932 to be removed from the patterning substrate
assembly 90, as illustrated in
Fig. 9E. The ferromagnetic layer(s) regions 954 remain on the exposed dielectric layer regions
922 in step 834.
[0101] In step 840, a carrier release layer and a dielectric layer are sequentially deposited
on a receiving substrate (e.g., a second substrate). Step 840 can be the same as step
640.
[0102] An example cross-sectional view of a receiving substrate assembly 92 that includes
a receiving substrate 960, a carrier release layer 970, and a dielectric layer 980
formed according to step 840 is illustrated in
Fig. 9F. The receiving substrate 960, the carrier release layer 970, and the dielectric layer
980 can be the same as or different than the patterning substrate 900, the carrier
release layer 910, and the dielectric layer 920, respectively. In addition, the receiving
substrate 960, the carrier release layer 970, and the dielectric layer 980 can be
the same as or different than the receiving substrate 760, the carrier release layer
770, and the dielectric layer 780, respectively.
[0103] In step 850, the ferromagnetic layer regions on the patterning substrate assembly
are placed in contact (e.g., direct physical contact) with the exposed dielectric
layer on the receiving substrate assembly.
[0104] Fig. 9G is an example cross-sectional view of the structure formed in step 850. The patterning
substrate assembly 90 in Fig. 9G has been flipped upside down compared to the patterning
substrate assembly 90 in Figs. 9A-7E. After the patterning substrate assembly 90 is
rotated vertically by 180 degrees, the patterning substrate assembly 90 and the receiving
substrate assembly 92 are move toward each other so that the ferromagnetic layer(s)
regions 954 on the patterning substrate assembly 90 are in contact (e.g., direct physical
contact) with the dielectric layer 980 in the receiving substrate assembly 92.
[0105] In step 860, a bond is formed between the ferromagnetic layer regions on the patterning
substrate assembly and the exposed dielectric layer on the receiving substrate assembly.
The bond can be formed by applying pressure to the patterning and receiving substrate
assemblies 90, 92 and/or by heating the patterning and receiving substrate assemblies
90, 92, for example as described above with respect to step 660. An optional vacuum
(e.g., less than or equal to about 10 µTorr) can be applied during step 860 to remove
or reduce the number of voids at the bonding interface. While the bond is formed,
the dielectric layer 920 and/or the dielectric layer 980 can reflow in step 870 to
fill the gaps between neighboring ferromagnetic layer(s) regions 954, for example
as illustrated in
Fig. 9H. Additionally or alternatively, a dielectric layer can be deposited (e.g., spun on)
to fill the gaps, for example according to step 680.
[0106] In step 880 (via placeholder B), the patterning substrate is detached from the patterning
substrate assembly. The patterning substrate is detached by activating the carrier
release layer in the patterning substrate assembly, such as by exposing the carrier
release layer to a solvent, exposing the carrier release layer to light, heating the
carrier release layer, and/or applying pressure or force to the carrier release layer.
Activating the carrier release layer can cause its physical integrity to decrease,
which can reduce the bond or adhesion between the carrier release layer and the patterning
substrate and/or between the carrier release layer and the dielectric layer. Step
880 can be the same as step 670.
[0107] Fig. 9I is an example cross-sectional view of the structure formed in step 880. In this example
cross-sectional view, the carrier release layer 910 is being removed by exposing the
carrier release layer 910 to light from a laser 905 that ablates or burns off the
carrier release layer 910 (e.g., to compromise the physical integrity of the carrier
release layer 910) to release or detach the patterning substrate 900, thereby detaching
the patterning substrate assembly 90 (e.g., the patterning substrate 900) from the
receiving substrate assembly 92. When the patterning substrate assembly 90 is detached
from the receiving substrate assembly 92, the dielectric layer 920 and the ferromagnetic
layer(s) regions 954 are transferred from the patterning substrate assembly 90 to
the receiving substrate assembly 92.
[0108] If additional ferromagnetic layer(s) are to be formed on or transferred to the receiving
substrate assembly (i.e., step 890=yes), the method 80 proceeds to step 892. In step
892, one or more additional ferromagnetic layer(s) are formed on a new patterning
substrate (e.g., in a new patterning substrate assembly. The ferromagnetic layer(s)
can be formed according to steps 800-834. The ferromagnetic layer(s) formed on the
new patterning substrate assembly are then bonded and transferred to the receiving
substate assembly in the same manner as in steps 850-880. One or both of the dielectric
layer(s) that are adjacent to the ferromagnetic layer(s) formed in step 892 are reflowed
in step 894, which can be the same as step 870. Additionally or alternatively, a dielectric
layer can be deposited (e.g., spun on) to fill the gaps, for example according to
step 680. In some embodiments, a total of 2 to 100 ferromagnetic layer(s) or another
number of ferromagnetic layer(s) can be formed or transferred to the receiving substrate
assembly.
[0109] Alternatively, the new patterning substrate can be prefabricated in which case step
892 only includes bonding and transferring the additional ferromagnetic layer(s) to
the receiving substate assembly, which can be performed in the same manner as steps
850-880.
[0110] In another embodiment, the additional ferromagnetic layer(s) can be formed according
to steps 600-630 or another method (e.g., as disclosed herein) and transferred according
to steps 650-670 or another method (e.g., as disclosed herein).
[0111] In some embodiments, the ferromagnetic layer regions 954 on the new patterning substrate
assembly can be placed directly over the ferromagnetic layer(s) regions 954 on the
receiving substrate assembly or they can be offset with respect to each other, which
can increase the packing density of ferromagnetic layers on the receiving substrate
assembly. One or more alignment structures can be formed on the receiving substrate
assembly and/or on the patterning substrate assembly, which can be used by optics
systems to align or offset the ferromagnetic layer regions with respect to each other.
[0112] Fig. 9J is an example cross-sectional view of the structure formed in step 892 and 894. The
receiving substrate 92 includes two layers or rows of ferromagnetic layer regions
954. The receiving substrate 92 also includes two dielectric layers 920 and two dielectric
layers 980.
[0113] After step 894, the method returns to step 890. This process can proceed in a loop
with steps 892 and 894 repeated until the desired number of layers or rows of ferromagnetic
layer regions 954 are formed on the receiving substrate assembly 92.
[0114] If no additional ferromagnetic layer(s) are to be formed on the receiving substrate
assembly (i.e., step 890=no), the method 80 proceeds to step 896 where the receiving
substrate is detached from the receiving substrate assembly. The receiving substrate
is detached by activating the carrier release layer in the receiving substrate assembly,
such as by exposing the carrier release layer to a solvent, exposing the carrier release
layer to light, heating the carrier release layer, and/or applying pressure or force
to the carrier release layer. Activating the carrier release layer can cause its physical
integrity to decrease, which can reduce the bond or adhesion between the carrier release
layer and the receiving substrate and/or between the carrier release layer and the
neighboring dielectric layer.
[0115] Fig. 9K is an example cross-sectional view of the structure formed in step 896 where the
receiving substrate assembly 92 had the same structure as in Fig. 9J prior to detaching
the receiving substrate 960 from the receiving substrate assembly 92. After the receiving
substrate 760 is detached and removed, a ferromagnetic-dielectric composite material
94 is formed, as illustrated in
Fig. 9L. The ferromagnetic-dielectric composite material 94 includes dielectric layers 980,
920, and ferromagnetic layer regions 954. Depending on how the ferromagnetic-dielectric
composite material 94 is formed, the ferromagnetic-dielectric composite material 94
can include additional or fewer rows of ferromagnetic layer regions 954. The easy
axes of magnetization can be aligned in the ferromagnetic layer regions 954. In addition,
the hard axes of magnetization can be aligned in the ferromagnetic layer regions 954.
The ferromagnetic-dielectric composite material 94 can be the same as ferromagnetic-dielectric
composite material 10.
[0116] Fig. 10 is a flow chart of a method 1000 for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment. Method 1000 can be used to manufacture material
10.
[0117] In step 1001, a carrier release layer and a dielectric layer are sequentially deposited
on a patterning substrate. The carrier release layer is deposited on the patterning
substrate and the dielectric layer is deposited on the carrier release layer. Step
1001 can be the same as step 800 and/or step 600.
[0118] An example cross-sectional view of a patterning substrate assembly 1100 that includes
a patterning substrate 1101, a carrier release layer 1110, and a dielectric layer
1120 formed according to step 1001 is illustrated in
Fig. 11A. The patterning substrate 1100, the carrier release layer 1110, and the dielectric
layer 1120 can be the same as the patterning substrate 700, the carrier release layer
710, and/or the dielectric layer 720, respectively. Additionally or alternatively,
the patterning substrate 1100, the carrier release layer 1110, and the dielectric
layer 1120 can be the same as the patterning substrate 900, the carrier release layer
910, and/or the dielectric layer 920, respectively.
[0119] In step 1010, a lift-off resist layer and a photoresist layer are sequentially deposited
on the dielectric layer. The photoresist layer is preferably a positive photoresist
layer but can also be a negative photoresist layer.
[0120] An example cross-sectional view of the patterning substrate assembly 1100 including
the lift-off resist layer 1130 and a photoresist layer 1140 is illustrated in
Fig. 11B.
[0121] In step 1020, a pattern is defined in the photoresist layer and the lift-off resist
layer is removed according to the patterned photoresist layer. The pattern can be
defined through photolithography and then removing the photoresist layer regions through
photolithography and exposure to light. The lift-off resist layer can be removed by
etching or exposing it to a solvent.
[0122] Fig. 11C is an example cross-sectional view of the patterning substrate assembly 1100 formed
in step 1020. The photoresist layer 1140 is formed into a pattern 1145 of isolated
photoresist layer regions 1142 by photolithography and development. Gaps or holes
1144 are formed between adjacent or neighboring isolated photoresist layer regions
1142. The gaps or holes 1144 are used to remove (e.g., etch) the underlying lift-off
resist layer 1130 to form isolated lift-off resist layer regions 1132. Gaps or holes
1134 are formed between adjacent or neighboring isolated lift-off resist layer regions
1132.
[0123] The isolated lift-off resist layer regions 1132 are aligned with the isolated photoresist
layer regions 1142. In addition, the gaps or holes 1134 are aligned with the gaps
or holes 1144. The gaps or holes 1134, 1144 reveal exposed dielectric layer regions
1122.
[0124] In step 1030, one or more ferromagnetic layer(s) is/are deposited onto the patterning
substrate assembly (e.g., onto the patterned photoresist layer and the patterned lift-off
resist layer). When more than one ferromagnetic layer is deposited, a non-ferromagnetic
layer, such as an insulator layer, can be deposited between some or all neighboring
ferromagnetic layers. Step 1030 can be the same as step 830 and/or step 620.
[0125] Fig. 11D is an example cross-sectional view of the patterning substrate assembly 1100, including
the ferromagnetic layer(s) 1150, formed in step 1030. The ferromagnetic layer(s) 1150
include ferromagnetic layer(s) regions 1152 that are deposited on the isolated photoresist
layer regions 1142 and ferromagnetic layer(s) regions 1154 that are deposited on the
exposed dielectric layer regions 1122 in the gaps or holes 1134, 1144. As such, the
ferromagnetic layer(s) 1150 conform to the pattern 1145.
[0126] In optional step 1032, a bias magnetic field is applied during or after the ferromagnetic
deposition step 1030 to set the easy axis or magnetization in a direction parallel
to the bias magnetic field, which can set the hard axis of magnetization in a direction
orthogonal to the bias magnetic field in the major plane of the ferromagnetic layer.
Step 1032 can be the same as step 832 and/or step 630. A cross-sectional illustration
of this step would appear the same or similar to as structure 70 in Fig. 7D.
[0127] In step 1034 (via placeholder A), the lift-off resist layer is exposed to a solvent.
The lift-off resist layer is partially, substantially, or fully soluble in the solvent.
Exposing the isolated lift-off resist layer regions 1132 to a solvent causes the isolated
photoresist layer regions 1142 and the ferromagnetic layer(s) regions 1152 to be lifted
off (e.g., removed) from the patterning substrate assembly 1100, as illustrated in
Fig. 11E. The ferromagnetic layer(s) regions 1154 remain on the exposed dielectric layer regions
1122 in step 1034.
[0128] The remaining steps of method 1000 (i.e., steps 840, 850, 860, 870, 880, 890, 892,
894, and 896) are the same as described in method 80. The cross-sectional illustrations
of the structures formed in the remaining steps of method 1000 are the same as described
in method 80 (i.e., Figs. 9F-9L).
[0129] Fig. 12 is a flow chart of a method 1200 for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment. Method 1200 can be used to manufacture material
10.
[0130] In step 1201, a carrier release layer and a dielectric layer are sequentially deposited
on a patterning substrate. The carrier release layer is deposited on the patterning
substrate and the dielectric layer is deposited on the carrier release layer. Step
1201 can be the same as step 1001, step 800 and/or step 600.
[0131] An example cross-sectional view of a patterning substrate assembly 1300 that includes
a patterning substrate 1301, a carrier release layer 1310, and a dielectric layer
1320 formed according to step 1201 is illustrated in
Fig. 13A. The patterning substrate 1300, the carrier release layer 1310, and the dielectric
layer 1320 can be the same as the patterning substrate 700, the carrier release layer
710, and/or the dielectric layer 720, respectively. Additionally or alternatively,
the patterning substrate 1300, the carrier release layer 1310, and the dielectric
layer 1320 can be the same as the patterning substrate 900, the carrier release layer
910, and/or the dielectric layer 920, respectively. Additionally or alternatively,
the patterning substrate 1300, the carrier release layer 1310, and the dielectric
layer 1320 can be the same as the patterning substrate 1100, the carrier release layer
1110, and the dielectric layer 1120, respectively.
[0132] In step 1210, the edge portion of the dielectric layer is removed to expose the underlying
edge portion of the carrier release layer. The edge portion of the dielectric layer
can be removed by selectively exposing the dielectric layer to a solvent, by exposing
the edge portion to light through photolithography and then exposing the dielectric
layer to a solvent, or by depositing and patterning a photoresist layer on the dielectric
layer and then etching the dielectric layer using the patterned photoresist layer.
[0133] An example cross-sectional view that illustrates the dielectric layer 1320 removed
at the edge 1305 is illustrated in
Fig. 13B. The removed dielectric layer 1320 reveals exposed carrier release layer regions 1314
at the edge 1305.
[0134] In step 1220, one or more ferromagnetic layer(s) is/are deposited on the patterning
substrate assembly (e.g., on the dielectric layer and the exposed carrier release
layer at the edge of the patterning substrate assembly). When more than one ferromagnetic
layer is deposited, a non-ferromagnetic layer, such as an insulator layer, can be
deposited between some or all neighboring ferromagnetic layers. Step 1220 can be the
same as step 1030, step 830, and/or step 620.
[0135] Fig. 13C is an example cross-sectional view of the patterning substrate assembly 1300, including
the ferromagnetic layer(s) 1330, formed in step 1220. The ferromagnetic layer(s) 1330
include ferromagnetic layer(s) regions 1332 that are deposited on the dielectric layer
1320 and ferromagnetic layer(s) regions 1334 that are deposited on the exposed carrier
release layer regions 1314.
[0136] In optional step 1222, a bias magnetic field is applied during or after the ferromagnetic
deposition step 1220 to set the easy axis or magnetization in a direction parallel
to the bias magnetic field, which can set the hard axis of magnetization in a direction
orthogonal to the bias magnetic field in the major plane of the ferromagnetic layer.
Step 1222 can be the same as step 1032, step 832, and/or step 630. A cross-sectional
illustration of this step would appear the same or similar to as structure 70 in Fig.
7D.
[0137] In step 1230, a photoresist layer is deposited and patterned on the patterning substrate
assembly (e.g., on the ferromagnetic layer(s)). The patterned photoresist layer includes
holes or gaps that expose portion of the underlying ferromagnetic layer(s).
[0138] Fig. 13D is an example cross-sectional view of the patterning substrate assembly 1300, including
the patterned photoresist layer 1340, formed in step 1230. The patterned photoresist
layer 1340 includes a pattern 1350 of holes 1342 that reveal exposed ferromagnetic
layer(s) regions 1336. The holes 1342 are over the ferromagnetic layer(s) regions
1332 and over the ferromagnetic layer(s) regions 1334.
[0139] In step 1232 (via placeholder A), the ferromagnetic layer(s) regions that are exposed
by the holes or gaps in the patterned photoresist layer are removed. The ferromagnetic
layer(s) can be removed by wet etching or another method.
[0140] Fig. 13E is an example cross-sectional view of the patterning substrate assembly 1300 formed
in step 1232. The exposed ferromagnetic layer(s) regions 1336 are removed leaving
patterned ferromagnetic layer(s) regions 1332 on the dielectric layer 1320 and the
exposed carrier release layer regions 1314. The removed dielectric layer 1320 at the
edge 1305 of the patterning substrate assembly 1300 provides a pathway for solvent
to contact the exposed carrier release layer regions 1314 during subsequent removal
of the patterning substrate 1301 and transfer of the patterned ferromagnetic layer(s)
regions 1332 to the receiving substrate.
[0141] In step 1240, a carrier release layer and a dielectric layer are sequentially deposited
on a receiving substrate (e.g., a second substrate). Step 1240 can be the same as
step 840 and/or step 640.
[0142] An example cross-sectional view of a receiving substrate assembly 1302 that includes
a receiving substrate 1360, a carrier release layer 1370, and a dielectric layer 1380
formed according to step 1240 is illustrated in
Fig. 13F. The receiving substrate 1360, the carrier release layer 1370, and the dielectric
layer 1380 can be the same as or different than the patterning substrate 1301, the
carrier release layer 1310, and the dielectric layer 1320, respectively. Additionally
or alternatively, the receiving substrate 1360, the carrier release layer 1370, and
the dielectric layer 1380 can be the same as or different than the receiving substrate
760, the carrier release layer 770, and the dielectric layer 780, respectively. Additionally
or alternatively, the receiving substrate 1360, the carrier release layer 1370, and
the dielectric layer 1380 can be the same as or different than the receiving substrate
960, the carrier release layer 970, and the dielectric layer 980, respectively.
[0143] In step 1250, the patterned ferromagnetic layer on the patterning substrate assembly
is placed in contact (e.g., direct physical contact) with the exposed dielectric layer
on the receiving substrate assembly. Step 1250 can be the same as step 850 and/or
step 650.
[0144] Fig. 13G is an example cross-sectional view of the structure formed in step 1250. The patterning
substrate assembly 1300 in Fig. 7G has been flipped upside down compared to the patterning
substrate assembly 1300 in Figs. 7A-7E. After the patterning substrate assembly 1300
is rotated vertically by 180 degrees, the patterning substrate assembly 1300 and the
receiving substrate assembly 1302 are moved towards each other so that the patterned
ferromagnetic layer(s) regions 1332 on the patterning substrate assembly 1300 are
in contact (e.g., direct physical contact) with the dielectric layer 1380 in the receiving
substrate assembly 1302.
[0145] In step 1260, a bond is formed between the patterned ferromagnetic layer on the patterning
substrate assembly and the dielectric layer on the receiving substrate assembly. Step
1260 can be the same as step 860 and/or step 660. In some embodiments, the dielectric
layer 1380 and/or the dielectric layer 1320 can reflow during step 1260 to fill the
holes or gaps between neighboring patterned ferromagnetic layer(s) regions 1332, for
example as illustrated in
Fig. 13H. The reflowed dielectric layer(s) 1320, 1380 do not fully cover the exposed carrier
release layer regions 1314.
[0146] In step 1270, the patterning substrate is detached from the patterning substrate
assembly. The patterning substrate is detached by activating the carrier release layer
in the patterning substrate assembly, such as by exposing the carrier release layer
(exposed carrier release layer regions 1314) to a solvent (e.g., via , exposing the
carrier release layer to light, heating the carrier release layer, and/or applying
pressure or force to the carrier release layer. Activating the carrier release layer
can cause its physical integrity to decrease, which can reduce the bond or adhesion
between the carrier release layer and the patterning substrate and/or between the
carrier release layer and the dielectric layer.
[0147] Fig. 13I is an example cross-sectional view of the structure formed in step 1270. In this
example cross-sectional view, the carrier release layer 1310 has been removed by exposing
the carrier release layer 1310 to a solvent. The solvent can initially contact the
exposed carrier release layer regions 1314 and then contact some or all the inner
regions of the carrier release layer 1310 as the exposed carrier release layer regions
1314 at least partially dissolves. As a result, the remainder of the patterning substrate
1301 is detached from the receiving substrate assembly 1302. When the patterning substrate
1301 is detached from the receiving substrate assembly 1302, the dielectric layer
1320 and the patterned ferromagnetic layer(s) regions 1332 are transferred from the
patterning substrate assembly 1300 to the receiving substrate assembly 1302.
[0148] In optional step 1280 (via placeholder B), a dielectric layer is deposited on the
receiving substrate assembly after the patterning substrate is detached from the receiving
substrate assembly. The dielectric layer can fill in the gaps, holes, or voids between
neighboring patterned ferromagnetic layer(s) regions 1332.
[0149] If additional ferromagnetic layer(s) are to be formed on or transferred to the receiving
substrate assembly (i.e., step 1290=yes), the method 1200 proceeds to step 1292. In
step 1292, one or more additional ferromagnetic layer(s) are formed on a new patterning
substrate (e.g., in a new patterning substrate assembly) in the same manner as in
steps 1200-1230 or according to another method (e.g., as described herein). The ferromagnetic
layer(s) formed on the new patterning substrate assembly are then bonded and transferred
to the receiving substate assembly in the same manner as in steps 1250-1280. Alternatively,
the new patterning substrate can be prefabricated in which case step 1292 only includes
bonding and transferring the additional ferromagnetic layer(s) to the receiving substate
assembly, which can be performed in the same manner as steps 1250-1280. The dielectric
layer(s) adjacent to the transferred ferromagnetic layer(s) can be reflowed during
step 1292 to fill the gaps between neighboring patterned ferromagnetic layer(s) regions.
In some embodiments, a total of 2 to 100 ferromagnetic layer(s) or another number
of ferromagnetic layer(s) can be formed or transferred to the receiving substrate
assembly.
[0150] In some embodiments, the patterned ferromagnetic layer(s) regions in the new patterning
substrate assembly can be placed directly over the patterned ferromagnetic layer(s)
regions 1332 in the receiving substrate assembly 1302 or they can be offset with respect
to each other, which can increase the packing density of ferromagnetic layers on the
receiving substrate assembly. One or more alignment structures can be formed on the
receiving substrate assembly and/or on the patterning substrate assembly, which can
be used by optics systems to align or offset the patterned ferromagnetic layer(s)
regions with respect to each other.
[0151] Fig. 13J is an example cross-sectional view of the structure formed in step 1292 where the
dielectric layer 1380 and/or the dielectric layer 1320 were reflowed during step 1260
to fill the holes or gaps between neighboring patterned ferromagnetic layer(s) regions
1332.
[0152] In optional step 1294, a dielectric layer is deposited on the receiving substrate
assembly after the new patterning substrate is detached from the receiving substrate
assembly to fill the gaps in the receiving substrate assembly. Optional step 1294
can be performed in the same manner as optional step 1280.
[0153] After optional step 1294, the method returns to step 1290. This process can proceed
in a loop with steps 1292 and 1294 repeated until the desired number of ferromagnetic
layer(s) are formed on the receiving substrate assembly.
[0154] If no additional ferromagnetic layer(s) are to be formed on the receiving substrate
assembly (i.e., step 1290=no), the method 1200 proceeds to optional step 1296 (via
placeholder C). In optional step 1296, a dielectric layer is deposited on the receiving
substrate assembly to fill any voids, holes, or gaps in the receiving substrate assembly.
[0155] In step 1298, the receiving substrate is detached from the receiving substrate assembly.
The receiving substrate is detached by activating the carrier release layer in the
receiving substrate assembly, such as by exposing the carrier release layer to a solvent,
exposing the carrier release layer to light, heating the carrier release layer, and/or
applying pressure or force to the carrier release layer. Activating the carrier release
layer can cause its physical integrity to decrease, which can reduce the bond or adhesion
between the carrier release layer and the receiving substrate and/or between the carrier
release layer and the neighboring dielectric layer.
[0156] Fig. 13K is an example cross-sectional view of the structure formed in step 1298 where the
receiving substrate assembly 72 had the same structure as in Fig. 13J prior to detaching
the receiving substrate 1360 from the receiving substrate assembly 1302. The carrier
release layer 1370 is removed in Fig. 13K. After the receiving substrate 1360 is detached
and removed, a ferromagnetic-dielectric composite material 1304 is formed, as illustrated
in
Fig. 13L. The ferromagnetic-dielectric composite material 1304 includes dielectric layers 1320
and 1380 and patterned ferromagnetic layer(s) regions 1332. Depending on how the ferromagnetic-dielectric
composite material 1304 is formed, the ferromagnetic-dielectric composite material
1304 can include additional or fewer rows of patterned ferromagnetic layer(s) regions
1332. The easy axes of magnetization can be aligned in the patterned ferromagnetic
layer(s) regions 1332. In addition, the hard axes of magnetization can be aligned
in the patterned ferromagnetic layer(s) regions 1332. The ferromagnetic-dielectric
composite material 1304 can be the same as ferromagnetic-dielectric composite material
10. The sides of the ferromagnetic-dielectric composite material 1304 can be planarized
to remove side portions of dielectric layers 1380, for example as illustrated in
Fig. 13M.
[0157] Fig. 14 is a flow chart of a method 1400 for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment. Method 1400 can be used to manufacture material
10.
[0158] In step 1401, one or more patterned ferromagnetic layers, on a first substrate assembly,
is placed in physical contact with a dielectric layer on a second substrate assembly.
The first substrate assembly, including the patterned ferromagnetic layer(s), can
be pre-fabricated or formed according to any of the methods described herein. For
example, the first substrate assembly can be formed according to steps 600-630, steps
800-832, steps 1001-1032, or steps 1200-1232. Step 1401 can be the same as step 650,
850, and/or 1250.
[0159] In step 1410, a bond is formed between the patterned ferromagnetic layer(s) and the
dielectric layer that have been placed in physical contact with each other. Step 1410
can be the same as step 660, step 860, or step 1260.
[0160] In step 1420, the patterned ferromagnetic layer(s) is/are transferred from the first
substrate assembly to the second substate assembly. This step can be performed by
activating a carrier release layer on the first substrate assembly to detach the first
substrate from the first substrate assembly. Step 1420 can be the same as step 670,
step 880, or step 1270.
[0161] In optional step 1430, a dielectric layer is optionally deposited on the patterned
ferromagnetic layer(s) to fill any gaps between adjacent/neighboring patterned ferromagnetic
layer regions. Alternatively, the dielectric layer(s) in the first and/or second substrate
assemblies can be reflowed (e.g., during step 1410) to fill any such gaps.
[0162] If additional ferromagnetic layer(s) are to be transferred to the second substrate
assembly (i.e., step 1440=yes), the method returns to step 1401 in a loop where one
or more additional ferromagnetic layers on a new first substrate assembly are placed
in contact with the dielectric layer on the patterned ferromagnetic layer regions
that was transferred to the second substate assembly in step 1420. This loop continues
until no additional ferromagnetic layer(s) are to be transferred to the second substrate
assembly (i.e., step 1440=no), in which case the method proceeds to step 1450 where
the second substrate is detached from the second substrate assembly. In some embodiments,
a total of 2 to 100 ferromagnetic layer(s) or another number of ferromagnetic layer(s)
can be formed or transferred to the receiving substrate assembly. The second substrate
can be detached by activating a carrier release layer on the second substrate assembly
to detach the second substrate from the second substrate assembly. Step 1450 can be
the same as step 698, step 896, or step 1298.
[0163] Fig. 15 is a cross-sectional illustration of an apparatus 1500 that can be used to support
the receiving substrate 1501 during transfer of the ferromagnetic layer(s) 1510 and
dielectric layer 1520 from the patterning substrate assembly 1502. The patterning
substrate assembly 1502 also includes a carrier release layer 1522 and a patterning
substrate 1524.
[0164] The apparatus 1500 includes a body 1530 that is configured to support the bottom
planar surface of the receiving substrate 1501. The body 1530 is wider than the receiving
substrate 1501 such that the body 1530 can also support a support ring 1540 that is
disposed around the receiving substrate 1501. The body 1530 and the support ring 1540
include threaded holes 1532, 1542 that are configured to engage complementary threads
on bolts 1550. The threaded holes 1532, 1542 are aligned so that the bolts 1550 can
engage and pass through both holes 1532, 1542.
[0165] A ring of adhesive such as double-sided polyimide tape 1560 is disposed on the support
ring 1540. A polyimide, polymer, or ceramic film layer 1570 is disposed on the double-sided
polyimide tape 1560 and the top surface of the receiving substrate 1501. The film
layer 1570 can have a thickness of about 20 µm or another thickness. A dielectric
layer such as SU-8 1580 is disposed on the film layer 1570. The SU-8 layer 1580 can
function as an adhesive between the film layer 1570 and the ferromagnetic layer 1510.
[0166] When the ferromagnetic layer(s) 1510 and dielectric layer 1520 are debonded from
the receiving substrate 1524, this can cause stress on the layers 1510, 1520. The
apparatus 1500 is configured to mechanically support the film layer 1570 from the
back using the receiving substrate 1501 and the support ring 1540.
[0167] The apparatus 1500 has a first state in which the bolts 1550 are in the holes 1532,
1542 to rigidly support or engage the support ring 1540. The apparatus 1500 is in
the first state in Fig. 15. The apparatus 1500 can be in the first state during transfer
of layers 1510, 1520 from the patterning substrate assembly 1502 to the receiving
substrate 1501. In addition, the apparatus can be in the first state during other
processing steps, such as depositing (e.g., spin coating) the SU-8 layer 1580 on the
film layer 1570.
[0168] The apparatus 1500 has a second state in which the bolts 1550 are removed at least
from hole 1542 to release the support ring 1540, as illustrated in
Fig. 16. The apparatus 1500 can be placed in the second state after all rows of ferromagnetic
layer(s) 1510 and dielectric layers 1520 are transferred to the receiving substrate
1501 to form material 1592 and the patterning substrate 1524 has been detached from
the patterning substrate assembly 1502. Material 1592 can be the same as material
10.
[0169] An air channel 1590 defined through the body 1530 can allow air to pass through to
release any suction between the support ring 1540 and the body 1530. The material
1592 and the support ring 1540 can be separated by at least partially removing the
film layer 1570, such as by cutting (e.g., laser cutting) the film layer 1570. The
receiving substrate, support ring, and body are constructed from steel, aluminum or
another material that is impervious to the solvents used in the previous release steps.
The body and receiving substrate are attached to the support ring during the process
of disposing a dielectric such as SU-8 on the supporting polymer film, and during
bonding. The support ring and the transferred ferromagnetic composite may be removed
from the support ring during immersion in a solvent while releasing the patterning
substrate, or during the final removal of the composite from the frame once all layers
have been transferred.
[0170] Fig. 17 is a flow chart of a method 1700 for manufacturing a ferromagnetic-dielectric composite
material according to another embodiment. Method 1700 can be used to manufacture material
10.
[0171] In step 1701, a carrier release layer is deposited on a substrate. An example cross-sectional
view of a substrate assembly 1800 that includes a substrate 1801 and a carrier release
layer 1810 formed according to step 1701 is illustrated in
Fig. 18A.
[0172] In step 1702, a pattern is defined in the carrier release layer. The pattern can
be defined in a photoresist layer deposited on the carrier release layer through photolithography.
The pattern can then be defined in the carrier release layer through etching or exposing
it to a solvent. After the pattern is defined in the carrier release layer, the remaining
photoresist layer can be removed with a solvent. An example cross-sectional view of
the substrate assembly 1800 that includes a patterned carrier release layer 1812 is
illustrated in
Fig. 18B. The patterned carrier release layer 1812 defines and/or reveals exposed substrate
regions 1802 according to a pattern 1805.
[0173] In step 1703, a first insulator layer is deposited on the patterned carrier release
layer and the exposed substrate regions. An example cross-sectional view of the substrate
assembly 1800 that includes a first insulator layer 1820 deposited on the patterned
carrier release layer 1812 and exposed substrate regions 1802 is illustrated in
Fig. 18C. The regions of the first insulator layer 1820 deposited on the patterned carrier
release layer 1812 form isolated insulator layer regions 1822 according to the pattern
1805. The regions of insulator layer 1820 deposited on the exposed substrate regions
1802 form isolated insulator layer regions 1824 according to the pattern 1805.
[0174] The first insulator layer 1820 can comprise the same material as or a different material
than dielectric 110 and/or non-ferromagnetic layer 510. The first insulator layer
1820 can have a thickness of about 2 nm to about 200 nm, including about 10 nm, about
25 nm, about 50 nm, about 75 nm, about 100 nm, about 125 nm, about 150 nm, about 175
nm, and any thickness or thickness range between any two of the foregoing thicknesses.
The thickness can be measured along or with respect to axis 1845.
[0175] In step 1704, a ferromagnetic layer is deposited on the first insulator layer. An
example cross-sectional view of the substrate assembly 1800 that includes a ferromagnetic
layer 1830 deposited on the first insulator layer 1820 is illustrated in
Fig. 18D. The ferromagnetic layer 1830 is deposited on the isolated insulator layer regions
1822, 1824 to form isolated ferromagnetic layer regions 1832, 1834, respectively,
according to the pattern 1805. The ferromagnetic layer 1830 can include a soft ferromagnetic
layer and/or a hard ferromagnetic layer. In some embodiments, each ferromagnetic layer
1830 can include a soft ferromagnetic layer and a hard ferromagnetic layer that are
magnetically coupled to each other, such as soft ferromagnetic layer 5021 and hard
ferromagnetic layer 5022 in ferromagnetic layer 520.
[0176] In step 1705, a second insulator layer is deposited on the ferromagnetic layer. An
example cross-sectional view of the substrate assembly 1800 that includes a second
insulator layer 1840 deposited on the ferromagnetic layer 1830 is illustrated in
Fig. 18E. The second insulator layer 1840 is deposited on the isolated ferromagnetic layer
regions 1832, 1834 to form isolated insulator regions 1842, 1844, respectively, according
to the pattern 1805.
[0177] If additional ferromagnetic layers are to be deposited (i.e., step 1706=yes), steps
1704 and 1705 are repeated to form additional alternating ferromagnetic and insulator
layers. Each ferromagnetic layer is located between and in physical contact with neighboring
first and second insulator layers. When no additional ferromagnetic layers are to
be deposited (i.e., step 1706=no), the method proceeds to optional step 1707 (via
placeholder A). The height or thickness, with respect to axis 1845, of the laminated
ferromagnetic layer(s) and insulator layers is preferably smaller than the height
or thickness, with respect to axis 1845, of the patterned carrier release layer 1812
such that an exposed portion 1814 of the patterned carrier release layer 1812 is maintained.
[0178] In optional step 1707, a bias magnetic field is applied during or after the ferromagnetic
deposition step(s) 1704. The bias magnetic field can permanently or semi-permanently
set the easy axis of magnetization of the ferromagnetic layer in a direction parallel
to the bias magnetic field. Permanently or semi-permanently setting the direction
of the easy axis of magnetization can permanently or semi-permanently set the direction
of the hard axis of magnetization in a direction orthogonal to the easy axis of magnetization
in the major plane of the ferromagnetic layer. When the bias magnetic field is applied
after the ferromagnetic deposition step(s) 1704, the bias magnetic field can be applied
while heating or annealing the substrate assembly 1800 in the form of a magnetic anneal
at a temperature of about 200°C to about 340°C with a magnetic field of about 0.1
Tesla to about 1.5 Tesla and a duration of about 10 to about 200 minutes. The structure
can be heated or annealed in an oven or can be placed near a heat source. The bias
magnetic field can be a DC magnetic field. The same magnetic field applied during
deposition of the ferromagnetic layer(s) can have the same magnitude and duration
as the magnetic field applied during the magnetic anneal.
[0179] Fig. 18F is an example cross-sectional view of the substrate assembly 1800 when an optional
bias magnetic field 1855 is applied. The easy axis of magnetization 1851 of the ferromagnetic
layer 1830 is permanently or semi-permanently aligned with the axis of the bias magnetic
field 1855. Aligning the easy axis of magnetization 1851 with the axis of the bias
magnetic field 1855 induces the hard axis of magnetization 1852 of the ferromagnetic
layer 1830 to be aligned in a direction orthogonal to the easy axis of magnetization
1851 within the major plane of the ferromagnetic layer 1830. For example, the major
plane of the ferromagnetic layer 1830 is parallel to the top surface 1803 of the substrate
1801.
[0180] In step 1708, the patterned carrier release layer is exposed to a solvent. The solvent
releases the material deposited on the patterned carrier release layer, such as by
at least partially dissolving the patterned carrier release layer. The released material
can be referred to as ferromagnetic film platelets, which can be the same as ferromagnetic
film platelets 100, 400, and/or 500 according to an embodiment.
[0181] Fig. 18G is an example cross-sectional view of the substrate assembly 1800 when the substrate
assembly 1800 including the patterned carrier release layer 1812 (e.g., exposed portion
1814 of the patterned carrier release layer 1812) is exposed a solvent 1860. The solvent
1860 causes the patterned carrier release layer 1812 to at least partially dissolve
to release the material deposited on the patterned carrier release layer 1812 (i.e.,
isolated insulator layer regions 1822, isolated ferromagnetic layer regions 1832,
and isolated second insulator regions 1842) to form ferromagnetic film platelets 1870.
The ferromagnetic film platelets 1870 are released into the solvent 1860. The material
deposited on the substrate 1801 (i.e., isolated insulator layer regions 1824, isolated
ferromagnetic layer regions 1834, and isolated second insulator regions 1844) are
not released by the solvent 1860. The solvent 1860 can comprise or consist of acetone,
isopropyl alcohol, a solvent stripper (e.g., an N-methylpyrrolidone (NMP)-based solvent
such as Remover-PG
™, available from Kayaku Advanced Materials), a photoresist developer (e.g., a metal-ion-free
(MIF) photoresist developer such as AZ-300-MIF
™, available from EMD Performance Materials Corp.), deionized water, and/or another
solvent.
[0182] In a first embodiment, the method 1700 can proceed through steps 1709-1711. In a
second embodiment, the method 1700 can proceed through steps 1719-1721.
[0183] In step 1709 of the first embodiment, the platelets are desiccated by evaporating
and/or removing the solvent. After the solvent is evaporated and/or removed, dry platelets
remain. The dry platelets can be placed or dispensed in a mold. Alternatively, the
platelets and the solvent can be placed or dispensed in a mold prior to desiccation.
[0184] In step 1710, a binding material is added to the platelets. The binding material
can comprise or consist of a thermoplastic binding agent such as PMMA or bisbenzocyclobutene
(BCB), or an epoxy. The binding material is preferably in liquid form.
Fig. 18H is an example cross-sectional view of a mold 1880 that holds the binding material
1875 and the platelets 1870. The platelets 1870 are in a disordered state where the
easy axes of magnetization 1851 of the isolated ferromagnetic layer regions 1832 in
the platelets 1870 are not aligned.
[0185] In step 1711, an optional bias magnetic field is applied to the binding material
and platelets in the mold. The bias magnetic field can be a DC magnetic field that
extends along an axis through the mold to align or substantially align the easy axes
of magnetization 1851 of the isolated ferromagnetic layer regions 1832 in the platelets
1870.
Fig. 18I is an example cross-sectional view of the mold 1880 when a bias magnetic field 1885
is applied. The bias magnetic field aligns or substantially aligns (e.g., within about
5° to about 10° of each other) the easy axes of magnetization 1851 of the isolated
ferromagnetic layer regions 1832 in the platelets 1870.
[0186] In step 1730, the binding material and the platelets are heated and compressed in
the mold. The heat and/or compression can cure the binding material to form a solid
in the shape of the mold (e.g., a coupon). The easy axes of magnetization 1851 of
the isolated ferromagnetic layer regions 1832 in the platelets 1870 can be aligned
or substantially aligned in the cured binding material 1875. The optional bias magnetic
field in step 1711 can be applied during at least some of step 1730 so that the easy
axes of magnetization 1851 remain substantially aligned until the binding material
is cured. The heat and compression can reduce the thickness of the cured binding material
1875 to a controlled thickness. The material can be heated to a temperature of about
90°C to about 400°C (including any value or range between these temperatures), and
a pressure of about 1MPa to about 1GPa (including any value or range between these
pressures), can be applied to compress the material. The temperature and pressure
can be based, at least in part, on the glass temperature of the binding material and
the desired final thickness of the coupon 1890. After the binding material 1875 is
cured and compressed, the coupon 1890 can be removed from the mold 1880, as illustrated
in
Fig. 18J.
[0187] In step 1719 of the second embodiment, a binding material is added to the solvent
after the ferromagnetic film platelets are released. The binding material added in
step 1719 can be the same as the binding material added in step 1710. The binding
material, the solvent, and the ferromagnetic film can be placed and/or added to a
mold (e.g., mold 1880). An example cross-sectional illustration of step 1719 can appear
the same as Fig. 18H, except that reference number 1875 would represent both the solvent
and the binding material
[0188] In step 1720, an optional bias magnetic field is applied to the solvent, binding
material, and platelets in the mold. The bias magnetic field can align or substantially
align the easy axes of magnetization 1851 of the isolated ferromagnetic layer regions
1832 in the platelets 1870. Step 1720 can be the same as step 1711. An example cross-sectional
illustration of step 1820 can appear the same as Fig. 18I, except that reference number
1875 would represent both the solvent and the binding material.
[0189] In step 1721, the platelets are desiccated by evaporating and/or removing the solvent.
Heat can be used to evaporate the solvent, which can also cure the binding material.
The easy axes of magnetization 1851 of the isolated ferromagnetic layer regions 1832
in the platelets 1870 can be aligned or substantially aligned in the cured binding
material. The optional bias magnetic field in step 1720 can be applied during at least
some of step 1721 so that the easy axes of magnetization 1851 remain substantially
aligned until the binding material is cured.
[0190] In step 1730, cured binding material and the platelets are heated and compressed
in the mold to form a coupon 1890. The heat and/or compression can reduce the thickness
of the cured binding material 1875. The coupon 1890 can be removed from the mold 1880,
as illustrated in
Fig. 18J.
[0191] Fig. 19 is an example cross-sectional illustration of a multilevel wiring structure 1900
that includes an inductor having a ferromagnetic polymer composite material core according
to an embodiment. The structure 1900 includes a multilevel wiring network 1940 having
multiple wiring planes 1942. The multilevel wiring network 1940 is electrically coupled
to active circuit components 1930, such as CMOS devices or transistors, that have
been fabricated on a semiconductor substrate 1920. The active circuit components 1930
can be any kind such as planar or three-dimensional transistors, FinFETs, or the like.
The substrate 1920 can be a bulk, SOI, Si-based, or other semiconductor-based substrate,
without limitation. Pertaining to the same die, and over the semiconductor substrate
1920 and the components 1930, the multilevel wiring network 1940 has been fabricated.
[0192] The multilevel wiring network 1940 is arranged into wiring planes 1942 and can include
addition or fewer wiring planes than those illustrated in Fig. 19. Each wiring plane
1942 contains conductive wire segments 1945. Electrical connections between conducive
wire segments 1945 of differing wiring planes 1942 are provided by conductive VIAs
1944. Also shown are typical IC chip contact structures 1943, usually referred to
in the art as C4 contacts, solder bumps, or copper pillars, but any other contacts
for the chip's external communication are acceptable without limitation. The spaces
in the wiring network 1940 are typically filled with a dielectric insulating material
1949, of which quite a few are known in the art, such as SiO
2.
[0193] An inductor 1950 is integrated into the multilevel wiring network 1940. The inductor
1950 includes a core 1952 that is formed of ferromagnetic polymer composite material
such as ferromagnetic polymer composite material 10. The wiring segments 1945 are
substantially parallel with the wiring planes 1942. The inductor 1950 further includes
a conductive winding 1954 that forms a general spiral on the outside of the core 1952.
The conductive winding 1954 is piecewise constructed of wire segments 1945 and of
VIAs 1944. The wire segments 1945 forming the conductive winding 1954 are disposed
in at least two of the wiring planes 1942 and the VIAs 1944 that form parts of the
conductive winding 1954 that are vertical or orthogonal to a principal plane 1901
of the core 1952 interconnect the wire segments 1945 in the at least two wiring planes
1942. The wire segment 1945' underneath the core 1952 is delineated with dashed lines
indicating that, depending how the conductive winding 1954 is constructed, it may
not be visible in the depicted cross-sectional plane. A wire segment can function
as a lead 1913 to the conductive winding 1954 is also shown.
[0194] The ferromagnetic polymer composite material in core 1952 includes rows of patterned
or isolated ferromagnetic layer regions 1960. The ferromagnetic layers in the patterned
or isolated ferromagnetic layer regions 1960 can be magnetically anisotropic such
that the easy and hard axes of magnetization 1962, 1964 of the ferromagnetic layers
are aligned in orthogonal directions with the principal plane of the respective ferromagnetic
layers. The easy and hard axes of magnetization 1962, 1964 in the patterned or isolated
ferromagnetic layer regions 1960 can be aligned in a common direction or orientation.
For example, in Fig. 19 the hard axes of magnetization 1964 are aligned with each
other and with a coil axis 1966 along which the conductive winding 1954 extends.
[0195] One or more optional components, shown as representative structures 1990, 1992, can
also be integrated into the multilevel wiring structure 1940. Each representative
structure 1990, 1992 can include one or more capacitors (e.g., trench capacitors,
MIM capacitors, etc.), resistors, transformers, diodes, and/or inductors. Such components,
including inductor 1950, can be electrically coupled in series, in parallel, or a
combination thereof, to one another.
[0196] The useful properties of the ferromagnetic composite material include a high permeability,
low coercivity and low AC loss from eddy currents. These properties are advantageous
for inductors, transformers, and antennae that are used in communications, signal
processing, and power converter circuits.
[0197] The invention should not be considered limited to the particular embodiments described
above, but rather should be understood to cover all aspects of the invention as fairly
set out in the attached claims. Various modifications, equivalent processes, as well
as numerous structures to which the invention may be applicable, will be apparent
to those skilled in the art to which the invention is directed upon review of this
disclosure. The claims are intended to cover such modifications and equivalents.
[0198] Also some aspects may be embodied as one or more methods. The acts performed as part
of the method may be ordered in any suitable way. Accordingly, embodiments may be
constructed in which acts are performed in an order different than illustrated, which
may include performing some acts simultaneously, even though shown as sequential acts
in illustrative embodiments.
[0199] The disclosure of the present application is further defined by the following items:
- 1. A method (60, 80, 1000, 1200, 1400, 1700) for manufacturing a ferromagnetic-dielectric
composite material (10, 74, 94, 1304), comprising:
placing patterned ferromagnetic layer regions, in a patterning substrate assembly
(70, 90, 1100, 1300, 1502), in physical contact with a second dielectric layer, the
second dielectric layer in a receiving substrate (92, 700, 760, 960, 1360, 1501, 1524)
assembly, wherein:
the patterning substrate assembly (70, 90, 1100, 1300, 1502) includes a patterning
substrate (700, 900, 1100, 1101, 1300, 1301, 1524), a first carrier release layer,
a first dielectric layer, and the patterned ferromagnetic layer regions, the first
carrier release layer disposed between the first dielectric layer and the patterning
substrate (700, 900, 1100, 1101, 1300, 1301, 1524), the first dielectric layer disposed
between the first carrier release layer and the patterned ferromagnetic layer regions;
the receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly includes a
receiving substrate (92, 700, 760, 960, 1360, 1501, 1524), a second carrier release
layer, and the second dielectric layer, the second carrier release layer disposed
between the second dielectric layer and the receiving substrate (92, 700, 760, 960,
1360, 1501, 1524);
forming a bond between the patterned ferromagnetic layer regions and the second dielectric
layer;
releasing the patterning substrate (700, 900, 1100, 1101, 1300, 1301, 1524) from the
patterning substrate assembly (70, 90, 1100, 1300, 1502) to transfer the patterned
ferromagnetic layer regions and the first dielectric layer from the patterning substrate
assembly (70, 90, 1100, 1300, 1502) to the receiving substrate (92, 700, 760, 960,
1360, 1501, 1524) assembly; and
releasing the receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) from the receiving
substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly to form the ferromagnetic-dielectric
composite material (10, 74, 94, 1304).
- 2. The method (60, 80, 1000, 1200, 1400, 1700) of item 1, further comprising activating
the first carrier release layer to detach the patterned ferromagnetic layer regions
from the patterning substrate assembly (70, 90, 1100, 1300, 1502) wherein preferably
activating the first carrier release layer comprises (a) exposing the first carrier
release layer to a solvent (1860) to at least partially dissolve the first carrier
release layer, (b) exposing the first carrier release layer to a light source to compromise
a physical integrity of the first carrier release layer, and/or (c) heating the first
carrier release layer to compromise the physical integrity of the first carrier release
layer.
- 3. The method of item 1 or 2, wherein activating the second carrier release layer
comprises (a) exposing the second carrier release layer to a solvent to at least partially
dissolve the second carrier release layer, (b) exposing the second carrier release
layer to a light source to compromise a physical integrity of the second carrier release
layer, and/or (c) heating the second carrier release layer to compromise the physical
integrity of the second carrier release layer.
- 4. The method (60, 80, 1000, 1200, 1400, 1700) of item 1, further comprising depositing
a lift-off photoresist on the patterning substrate (700, 900, 1100, 1101, 1300, 1301,
1524) to form the first carrier release layer
- 5. The method of one of items 1 to 4, further comprising:
depositing the first dielectric layer on the first carrier release layer;
defining a first pattern in the first dielectric layer, the first pattern comprising
first dielectric layer regions and holes (746, 934, 1342, 1532, 1542) defined between
neighboring first dielectric layer regions;
defining a second pattern in the first carrier release layer according to the pattern
(730, 940, 1350, 1805) in the first dielectric layer, the second pattern in the first
carrier release layer comprising first carrier release layer regions and holes (746,
934, 1342, 1532, 1542) defined between neighboring first carrier release layer regions,
wherein the first carrier release layer regions are aligned with the first dielectric
layer regions and the holes (746, 934, 1342, 1532, 1542) between neighboring first
carrier release layer regions are aligned with the holes (746, 934, 1342, 1532, 1542)
between neighboring first dielectric layer regions to reveal exposed patterning substrate
(700, 900, 1100, 1101, 1300, 1301, 1524) regions; and
after defining the second pattern, depositing a ferromagnetic material on the first
carrier release layer regions to form first ferromagnetic layer regions on the first
dielectric layer regions and first ferromagnetic layer regions on the exposed patterning
substrate (700, 900, 1100, 1101, 1300, 1301, 1524) regions,
wherein the patterned ferromagnetic layer regions comprise the first ferromagnetic
layer regions such that the first ferromagnetic layer regions are placed in physical
contact with the second dielectric layer in the receiving substrate (92, 700, 760,
960, 1360, 1501, 1524) assembly.
- 6. The method (60, 80, 1000, 1200, 1400, 1700) of item 5, wherein the ferromagnetic
material comprises a soft ferromagnetic material and the method (60, 80, 1000, 1200,
1400, 1700) further comprising applying a bias magnetic field to set an easy axis
of magnetization of the soft ferromagnetic material.
- 7. The method (60, 80, 1000, 1200, 1400, 1700) of item 5, wherein releasing the patterning
substrate (700, 900, 1100, 1101, 1300, 1301, 1524) from the patterning substrate assembly
(70, 90, 1100, 1300, 1502) transfers the first ferromagnetic layer regions and the
first dielectric layer regions from the patterning substrate assembly (70, 90, 1100,
1300, 1502) to the receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly,
the method preferably further comprising after releasing the patterning substrate
(700, 900, 1100, 1101, 1300, 1301, 1524) from the patterning substrate assembly (70,
90, 1100, 1300, 1502), depositing a third dielectric layer on the patterning substrate
assembly (70, 90, 1100, 1300, 1502) to fill the holes (746, 934, 1342, 1532, 1542)
between neighboring first dielectric layer regions and respective holes (746, 934,
1342, 1532, 1542) between neighboring first ferromagnetic layer regions, the method
more preferably further comprising spin-coating the third dielectric layer on the
patterning substrate assembly (70, 90, 1100, 1300, 1502).
- 8. The method (60, 80, 1000, 1200, 1400, 1700) of item 1, further comprising:
depositing the first dielectric layer on the first carrier release layer;
depositing a ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021,
5022) on the first dielectric layer; and
defining a pattern (730, 940, 1350, 1805) in the ferromagnetic layer (120, 421, 422,
510, 520, 740, 1510, 1830, 5021, 5022), the pattern (730, 940, 1350, 1805) comprising
the patterned ferromagnetic layer regions and holes (746, 934, 1342, 1532, 1542) between
neighboring ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021, 5022)
regions.
- 9. The method (60, 80, 1000, 1200, 1400, 1700) of item 8, wherein defining a pattern
(730, 940, 1350, 1805) in the ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510,
1830, 5021, 5022) comprises:
depositing photoresist layer (930, 1140, 1340) on the ferromagnetic layer (120, 421,
422, 510, 520, 740, 1510, 1830, 5021, 5022);
defining a pattern (730, 940, 1350, 1805) in the photoresist layer (930, 1140, 1340)
to form photoresist layer regions (932, 1142) and holes (746, 934, 1342, 1532, 1542)
between neighboring photoresist layer regions (932, 1142), the holes (746, 934, 1342,
1532, 1542) revealing exposed ferromagnetic layer regions; and
removing the exposed ferromagnetic layer regions, wherein preferably:
the first carrier release layer comprises a lift-off photoresist layer, and
the method (60, 80, 1000, 1200, 1400, 1700) further comprises removing an edge region
of the first dielectric layer to reveal exposed lift-off photoresist layer regions
(932, 1142) at an edge region of the lift-off photoresist layer.
- 10. The method (60, 80, 1000, 1200, 1400, 1700) of item 1, wherein forming the bond
between the patterned ferromagnetic layer regions and the second dielectric layer
comprises heating and applying pressure to the patterned ferromagnetic layer regions
and the second dielectric layer, wherein preferably:
holes (746, 934, 1342, 1532, 1542) are defined between neighboring patterned ferromagnetic
layer regions, and
the method (60, 80, 1000, 1200, 1400, 1700) further comprises while heating the patterned
ferromagnetic layer regions and the second dielectric layer, re-flowing the first
dielectric layer and/or the second dielectric layer to fill the holes (746, 934, 1342,
1532, 1542).
- 11. The method (60, 80, 1000, 1200, 1400, 1700) of item 1, further comprising:
depositing the first carrier release layer on the patterning substate;
depositing the first dielectric layer on the first carrier release layer;
depositing a photoresist layer (930, 1140, 1340) on the first dielectric layer;
defining a pattern (730, 940, 1350, 1805) in the photoresist layer (930, 1140, 1340)
to form photoresist layer regions (932, 1142) and holes (746, 934, 1342, 1532, 1542)
defined between neighboring photoresist layer regions (932, 1142), the holes (746,
934, 1342, 1532, 1542) revealing exposed first dielectric layer regions;
depositing a ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021,
5022) on the patterning substate assembly, the ferromagnetic layer (120, 421, 422,
510, 520, 740, 1510, 1830, 5021, 5022) comprising first ferromagnetic layer regions
disposed on the photoresist layer regions (932, 1142) and second ferromagnetic layer
regions disposed on the exposed first dielectric layer regions; and
exposing the remaining patterned photoresist layer regions (932, 1142) to a solvent
(1860) to remove the remaining patterned photoresist layer regions (932, 1142), thereby
removing the first ferromagnetic layer regions,
wherein the patterned ferromagnetic layer regions comprise the second ferromagnetic
layer regions such that the second ferromagnetic layer regions are placed in physical
contact with the second dielectric layer in the receiving substrate (92, 700, 760,
960, 1360, 1501, 1524) assembly, wherein preferably:
forming the bond between the patterned ferromagnetic layer regions and the second
dielectric layer comprises heating and applying pressure to the second ferromagnetic
layer regions and the second dielectric layer,
holes (746, 934, 1342, 1532, 1542) are defined between neighboring second ferromagnetic
layer regions, and
the method (60, 80, 1000, 1200, 1400, 1700) further comprises while heating the second
ferromagnetic layer regions and the second dielectric layer, re-flowing the first
dielectric layer and/or the second dielectric layer to fill the holes (746, 934, 1342,
1532, 1542).
- 12. The method (60, 80, 1000, 1200, 1400, 1700) of item 1, further comprising:
depositing the first carrier release layer on the patterning substate;
depositing the first dielectric layer on the first carrier release layer;
depositing a lift-off photoresist layer on the first dielectric layer;
depositing a photoresist layer (930, 1140, 1340) on the lift-off photoresist layer;
defining a first pattern in the photoresist layer (930, 1140, 1340) to form photoresist
layer regions (932, 1142) and holes (746, 934, 1342, 1532, 1542) defined between neighboring
photoresist layer regions (932, 1142);
defining a second pattern in the lift-off resist layer according to the first pattern,
the second pattern forming lift-off resist layer regions (1132) and holes (746, 934,
1342, 1532, 1542) defined between neighboring lift-off resist layer regions (1132),
wherein the lift-off resist layer regions (1132) are aligned with the photoresist
layer regions (932, 1142) and the holes (746, 934, 1342, 1532, 1542) between neighboring
lift-off resist layer regions (1132) are aligned with the between neighboring photoresist
layer regions (932, 1142) to reveal exposed first dielectric layer regions;
depositing a ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021,
5022) on the patterning substate assembly, the ferromagnetic layer (120, 421, 422,
510, 520, 740, 1510, 1830, 5021, 5022) comprising first ferromagnetic layer regions
disposed on the photoresist layer regions (932, 1142) and second ferromagnetic layer
regions disposed on the exposed first dielectric layer regions; and
exposing the lift-off resist layer regions (1132) to a solvent (1860) to remove the
lift-off resist layer regions (1132), thereby removing the photoresist layer regions
(932, 1142) and the first ferromagnetic layer regions,
wherein the patterned ferromagnetic layer regions comprise the second ferromagnetic
layer regions such that the second ferromagnetic layer regions are placed in physical
contact with the second dielectric layer in the receiving substrate (92, 700, 760,
960, 1360, 1501, 1524) assembly.
- 13. The method (60, 80, 1000, 1200, 1400, 1700) of item 1, further comprising placing
the receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly on a support
apparatus that comprises:
a body (1530) having a planar center region and an edge region, the planar region
configured to support a back surface of the receiving substrate (92, 700, 760, 960,
1360, 1501, 1524);
a support ring (1540) disposed on the edge region of the body (1530);
a plurality of bolts (1550) that releasably engage the edge region of the body (1530)
and the support ring (1540);
a double-sided polyimide tape (1560) disposed along the support ring (1540);
a polyimide, polymer, or ceramic film layer disposed on the receiving substrate (92,
700, 760, 960, 1360, 1501, 1524) and the double-sided polyimide tape (1560); and
a dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520) disposed on and
covering the polyimide, polymer, or ceramic film layer.
- 14. A method (60, 80, 1000, 1200, 1400, 1700) for manufacturing a ferromagnetic-dielectric
composite material (10, 74, 94, 1304), comprising:
- (a) placing first patterned ferromagnetic layer regions, in a first patterning substrate
assembly in a plurality of patterning assemblies, in physical contact with a second
receiving dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520), the
second receiving dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520)
in a receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly, wherein:
each patterning substrate assembly (70, 90, 1100, 1300, 1502) includes a respective
patterning substrate (700, 900, 1100, 1101, 1300, 1301, 1524), a first respective
carrier release layer (710, 770, 910, 970, 1110, 1310, 1370, 1522, 1810), a first
respective dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520), and
respective patterned ferromagnetic layer regions, the first respective carrier release
layer (710, 770, 910, 970, 1110, 1310, 1370, 1522, 1810) disposed between the first
respective dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520) and
the respective patterning substrate (700, 900, 1100, 1101, 1300, 1301, 1524), the
first respective dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520)
disposed between the first respective carrier release layer (710, 770, 910, 970, 1110,
1310, 1370, 1522, 1810) and the respective patterned ferromagnetic layer regions,
and
the receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly includes a
receiving substrate (92, 700, 760, 960, 1360, 1501, 1524), a second carrier release
layer, and the second receiving dielectric layer (720, 780, 790, 920, 980, 1120, 1320,
1380, 1520), the second carrier release layer disposed between the second receiving
dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520) and the receiving
substrate (92, 700, 760, 960, 1360, 1501, 1524);
- (b) forming a bond between the first patterned ferromagnetic layer regions and the
second receiving dielectric layer (720, 780, 790, 920, 980, 1120, 1320, 1380, 1520);
- (c) releasing the first patterning substrate from the patterning substrate assembly
(70, 90, 1100, 1300, 1502) to transfer the first patterned ferromagnetic layer regions
and a first dielectric layer from the first patterning substrate assembly to the receiving
substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly;
- (d) placing second patterned ferromagnetic layer regions, in a second patterning substrate
assembly in the plurality of patterning assemblies, in physical contact with the first
dielectric layer in the receiving substrate (92, 700, 760, 960, 1360, 1501, 1524)
assembly;
- (e) forming a bond between the second patterned ferromagnetic layer regions and the
first dielectric layer;
- (f) releasing a second patterning substrate from the second patterning substrate assembly
to transfer the second patterned ferromagnetic layer regions and the second dielectric
layer from the first patterning substrate assembly to the receiving substrate (92,
700, 760, 960, 1360, 1501, 1524) assembly; and
- (g) releasing the receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) from the
receiving substrate (92, 700, 760, 960, 1360, 1501, 1524) assembly to form the ferromagnetic-dielectric
composite material (10, 74, 94, 1304).
- 15. The method (60, 80, 1000, 1200, 1400, 1700) of item 14, further comprising repeating
steps (d)-(f), prior to step (g), to form a stack of the second patterned ferromagnetic
layer regions.
- 16. A method (60, 80, 1000, 1200, 1400, 1700) for manufacturing a ferromagnetic-dielectric
composite material (10, 74, 94, 1304), comprising:
depositing a carrier release layer (710, 770, 910, 970, 1110, 1310, 1370, 1522, 1810)
on a substrate;
defining a pattern (730, 940, 1350, 1805) in the carrier release layer (710, 770,
910, 970, 1110, 1310, 1370, 1522, 1810) to form patterned carrier release layer (1812),
the patterned carrier release layer (1812) defining exposed substrate regions (1802);
depositing a first insulator layer (1820) on the patterned carrier release layer (1812)
and the exposed substrate regions (1802) to form first and second isolated insulator
layer regions, the first isolated insulator layer regions disposed on the patterned
carrier release layer (1812), each second isolated insulator layer region disposed
on a respective exposed substrate region;
depositing a ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021,
5022) on the first insulator layer (1820) to form first and second isolated ferromagnetic
layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021, 5022) regions, each first isolated
ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021, 5022) region
disposed on a respective first isolated insulator layer region, each second ferromagnetic
layer region disposed on a respective second isolated insulator layer region;
depositing a second insulator layer (1840) on the ferromagnetic layer (120, 421, 422,
510, 520, 740, 1510, 1830, 5021, 5022) to form a third and fourth isolated insulator
layer regions, each third isolated insulator layer region disposed on a respective
first isolated ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021,
5022) region, each fourth isolated insulator layer region disposed on a respective
second isolated ferromagnetic layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021,
5022) region;
exposing the carrier release layer (710, 770, 910, 970, 1110, 1310, 1370, 1522, 1810)
to a solvent (1860) to release a plurality of ferromagnetic film platelets (100, 400,
1870), each ferromagnetic film platelet (100, 400, 500, 1870) including the respective
first isolated insulator layer region, the respective first isolated ferromagnetic
layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021, 5022) region, and a respective
third isolated insulator layer region;
desiccating the ferromagnetic film platelets (100, 400, 1870);
adding a binding material (1875) to the ferromagnetic film platelets (100, 400, 1870);
and
forming a coupon (1890) that includes the ferromagnetic film platelets (100, 400,
1870).
- 17. The method (60, 80, 1000, 1200, 1400, 1700) of item 16, wherein the ferromagnetic
film platelets (100, 400, 1870) are desiccated before the binding material (1875)
is added, wherein preferably the binding material (1875) is in a liquid form when
the binding material (1875) is added to the ferromagnetic film platelets (100, 400,
1870), the method more preferably further comprising applying a bias magnetic field
to align an easy axis of magnetization of the respective first isolated ferromagnetic
layer (120, 421, 422, 510, 520, 740, 1510, 1830, 5021, 5022) region of each ferromagnetic
film platelet (100, 400, 500, 1870) in a liquid binding material, the method even
more preferably further comprising curing the liquid binding material to form a coupon
(1890) that includes a solid binding material and the ferromagnetic film platelets
(100, 400, 1870), the easy axes of magnetization substantially aligned with each other
- 18. The method (60, 80, 1000, 1200, 1400, 1700) of item 16, wherein the ferromagnetic
film platelets (100, 400, 1870) are desiccated after the binding material (1875) is
added to the ferromagnetic film platelets (100, 400, 1870) and the solvent (1860),
the method preferably further comprising applying a bias magnetic field to align an
easy axis of magnetization of the respective first isolated ferromagnetic layer (120,
421, 422, 510, 520, 740, 1510, 1830, 5021, 5022) region of each ferromagnetic film
platelet (100, 400, 500, 1870) in the solvent (1860) and the binding material (1875),
wherein more preferably desiccating the ferromagnetic film platelets (100, 400, 1870)
includes:
evaporating the solvent (1860); and
curing the binding material (1875),
wherein the desiccating occurs while the easy axes of magnetization are substantially
aligned with each other.