Technical Field
[0001] The disclosure relates to a distribution system for a process fluid and an electric
current for a chemical and/or electrolytic surface treatment of a substrate, a distribution
module for a process fluid and an electric current for a chemical and/or electrolytic
surface treatment of a substrate and a distribution method for a process fluid and
an electric current for a chemical and/or electrolytic surface treatment of a substrate.
Technical Background
[0002] Electroplating, e.g. of copper, is a frequently used technology in many different
industries, especially in the semiconductor related industries. Due to the simplicity
and scalability of the process, electroplating is used to metallize surfaces or parts
of surfaces of various types of substrates having various sizes.
[0003] In order to achieve adequate film quality and uniformity during the electroplating
process, it is necessary to guarantee a very well balanced electrical current distribution
over the surface area as well as a uniform and adequate metal-ion supply through an
electrolyte to the surface to be plated. As the substrate is covered with extremely
small and sensitive device structures, no direct electrical contact can be made within
the substrate area, except within narrow regions at substrate edges. Therefore, an
electrically conductive seed-layer is required to distribute the current from the
contacts of the substrate edges throughout the surface.
[0004] The main challenge associated with the seed-layer and the uniformity of the electrical
current distribution over the surface area is called "terminal effect". The terminal
effect describes a potential drop across a surface area, which can occur due to a
relatively high resistivity of such a seed-layer, which is usually required for the
electroplating process of a substrate. Depending on the seed-layer material, its thickness
and the distance between the plating area and the electrical contact at the edge of
the substrate, a potential drop of several volts is likely to occur. Such potential
drop from the substrate edge to the area to be plated results in a highly non-uniform
current density distribution leading to an extremely non-uniform plating thickness
distribution, primarily characterized by a thicker plating at the substrate edges.
[0005] Additional challenges associated with the current distribution that need to be faced,
especially with increasingly smaller structures, may be the equilibration of the current
distribution between substrate areas with a very high-density of tiny structures and
areas with a low density of rather larger structures to be electroplated.
[0006] In the prior art, several technologies address the mitigation of the macroscopic
terminal effect, which addresses the "center-to-edge" potential drop, by adding a
thief cathode. However, the thief cathode as used in the prior art has only provided
limited success. Therefore, the overall non-uniformity problem is not yet fundamentally
solved.
Summary disclosure
[0007] Hence, there may be a need to provide an improved distribution system for a process
fluid and an electric current for chemical and/or electrolytic surface treatment of
a substrate, which allows increasing the plating uniformity, particularly for applications
in high performance devices, particularly with very small, device structures.
[0008] This problem is solved by the subject-matters of the independent claims, wherein
further embodiments are incorporated in the dependent claims. It should be noted that
the aspects of the disclosure described in the following apply also to a distribution
system for a process fluid and an electric current for a chemical and/or electrolytic
surface treatment of a substrate, a distribution module for a process fluid and an
electric current for a chemical and/or electrolytic surface treatment of a substrate,
and a distribution method for a process fluid and an electric current for a chemical
and/or electrolytic surface treatment of a substrate.
[0009] According to the present disclosure, a distribution system for a process fluid and
an electric current for a chemical and/or electrolytic surface treatment of a substrate
is presented. The distribution system comprises a distribution body, a primary cathode,
and a secondary cathode. The distribution body comprises several openings for the
process fluid and the electric current, wherein the several openings are arranged
at a front face of the distribution body, the front face being directed to the primary
cathode. The primary cathode and the secondary cathode are arranged to attract the
electric current and to guide the electric current to the substrate, preferably to
predefined areas of the substrate to be treated. The secondary cathode comprises several
cathode pixels, wherein the several cathode pixels are distributed in an array to
be aligned with at least an area of the substrate to be treated. Additionally, the
several cathode pixels are individually controllable for adjusting a distribution
of the electric current at the substrate.
[0010] The secondary cathode may be spaced apart from the primary cathode and may comprise
several cathode pixels being distributed in an array to be aligned with an area of
the substrate to be treated. This arrangement may enable a localized control and tuning
of the current density distribution, particularly with a tuning resolution down to
the sub-µm range. The individually controllable cathode pixels may enable a very localized
adjustment and tuning of the current density distribution all over a surface of the
substrate to be treated, not only at the edge areas of the substrate. Therefore, the
distribution system may allow effecting the edge-to-center/center-to-edge as well
as the current density distribution within the substrate to be plated. Furthermore,
the distribution system according to the disclosure may enable the plating of non-rotating
substrates as well as of rotating substrates.
[0011] The secondary cathode may be made from an electrically conducting material, preferably
inert to the chemical environment of the electrolyte, e.g. inert metals, such as palladium,
palladium-coated materials, platinum and/or platinized materials like tantalum, tungsten,
and/or titanium, or may be made from the same material as a plating material to be
used for the surface treatment of the substrate. For example, a Cu-comprising secondary
cathode may be used when Cu is plated. Further, the secondary cathode may have a circular,
square, rectangular, C-shaped, wire-shaped and/or partially electrically insulated
shape. The secondary cathode may work as a thief cathode mitigating the terminal effect
by increasing the plating-uniformity. Additionally, or alternatively, the secondary
cathode may be formed by several pixels, wherein the pixels may be separate from each
other, wherein each pixel may be individually controllable. Therefore, the secondary
cathode may be referred as pixelated cathode. Further, the secondary cathode may be
directed towards the primary cathode.
[0012] In an embodiment, the distribution system may further comprise at least a power source
configured to apply individual voltage potentials to the cathode pixels to individually
control the cathode pixels. In an embodiment, at least some of the cathode pixels
may be each connected to a single power source.
[0013] The cathode pixels may be each connected to the at least one power source by electrical
connecting lines transmitting a potential from the at least one power source to the
cathode pixels. Additionally or alternatively, the cathode pixels their selves can
be at least partially formed as a wire. At least some of the cathode pixels may be
together connected to a single power source. To sum it up, the cathode pixels may
be each connected to the same power source, or the cathode pixels may be each connected
to individual power sources, resulting in that the number of power sources corresponds
to the number of cathode pixels. Alternatively, the power source may comprise several
power outlets, each pixel being connected to an individual power outlet of the one
power source. Additionally, or alternatively, the cathode pixels may be divided into
several groups of pixels, wherein the pixels of each group may be connected to the
same power source, but each group of pixels is connected to a separate power source.
[0014] In an embodiment, at least some cathode pixels being controlled by a single power
source may have individual potentials. In this case, the cathode pixels may be configured
to display a variety of different pixel potentials by providing variable resistances
between the power source and the individual cathode pixel.
[0015] In an embodiment, the distribution system may further comprise at least a processing
unit configured to control the at least one power source to apply the individual voltage
potentials to the cathode pixels for individual durations.
[0016] In principle, each cathode pixel may be fabricated in a way to permit individual
controllability of the applied potential and/or the duration of the applied potential.
At least some of the cathode pixels may be grouped to arrays and each array is connected
to one of several power sources for being applied with the same potential and same
duration.
[0017] The power source(s) may have a cathodic potential or an anodic potential. In particular,
the anodic potential may be used for achieving an improved pixelated reverse pulse
plating or for cleaning the pixels from potentially deposited metal layers or particles.
Additionally, or alternatively, the cathode pixels may be arranged at a rear face
of the distribution body, wherein the rear face is opposite to the front face of the
distribution body.
[0018] In an embodiment, the control for adjusting the distribution of the electric current
at the substrate may be a physical arrangement of cathode pixels. Thus, the pixels
may be arranged according to a predefined pattern, e.g. a photolithographic mask,
which is used to create the pattern distribution on the substrate to be treated. Additionally,
or alternatively, the cathode pixels can be electrically tuned according to the substrate
pattern densities and substrate irregularities.
[0019] In an embodiment, the cathode pixels may be arranged at the distribution body. The
cathode pixels may be arranged in or on a surface of the distribution body. In an
embodiment, the cathode pixels may be arranged at the front face of the distribution
body directed to the first cathode. For example, the cathode pixels may be mainly
arranged around the openings at the front face. Thereby, the cathode pixels may be
integrated into the distribution body surface through common processes used in the
semiconductor and/or flat panel industry, like one or more photolithographic process
sequences. Alternatively, at least some of the cathode pixels and electrical connecting
lines may be manufactured on the surface via printing. The electrical connecting lines
may be fabricated in a similar way as the (individual) cathode pixels.
[0020] The openings at the front face may be configured at least partially as jet holes
directing the process fluid and/or the electric current towards the substrate to be
treated and/or at least partially as connecting passages draining off the process
fluid from the substrate to be treated. In an embodiment, the front face and the rear
face of the distribution body may be connected by the connecting passages through
the distribution body, wherein the cathode pixels are arranged at least partially
around the connecting passages. The connecting passages may be configured to permit
a backflow and with this a circulation of the process fluid through the distribution
body. Arranging the cathode pixels around the connecting passaged can be an easy way
to integrate the cathode pixels into the distribution body.
[0021] In an embodiment, the secondary cathode may be separate to the distribution body
and positioned adjacent to the distribution body in a direction towards the substrate.
[0022] Thus, the secondary cathode may be implemented as a stand-alone system. As the simplest
example of such a stand-alone system, the secondary cathode may correspond to a mostly
electrically isolated wire with an electrically non-isolated tip. In a more typical
example, multiple cathode pixels may be physically connected together in a predefined
specific geometric constellation, preferably defined by and aligned with the requirements
of an "open area density" distribution on the substrate. This stand-alone system can
be placed between the distribution body and the primary cathode to enable the tuning
of the current density distribution all over the substrate to be treated, and in particular
to enable the tuning of the current density distribution for individual areas and/or
individual device structures of the substrate to be treated.
[0023] The "open area density" may define the density degree of open areas and/or the size
of those open areas in a predefined area of the substrate. The open areas may be configured
to be the areas of the substrate to be treated or plated. When a constant potential
may be applied on the whole substrate, the current distribution, particularly the
distribution of electrons, may depend on the density degree and/or the size of the
open areas, wherein the distribution of the electrons may affect the current density
and thereby the amount of the plating material being deposited in this area. Different
current densities in different areas of the substrate may lead to different amount
of deposited plating material in the different areas resulting in a non-uniform distribution
of the plating material. Thus, providing the pixels with different potentials may
allow controlling the current density distribution to achieve a uniform current density
distribution and thus, a uniform distribution of the plating material.
[0024] In an electrical sense, the cathode pixels may not be electrically connected with
each other, but individually controllable through being individually electrically
connected to individual power supplies, as described above, or to one power supply
having adequate multiple power outlets. In specific cases, the cathode pixels may
also be grouped as to enable electrical power control on various groups of cathode
pixels.
[0025] Furthermore, the secondary cathode may preferably be placed in a first predefined
distance to the distribution body and in a second predefined distance to the substrate.
The first predefined distance may be equal to the second predefined distance. Alternatively,
the first predefined distance may be different to the second predefined distance.
The predefined first and second distances may be dependent on the plating material
and/or the size of the substrate and/or the process fluid and/or the open area density
distribution of the device structures on the substrate to be plated. Further, the
first and the second predefined distances may be constant or correspond to a predefined
range, within the distances may be adaptable during the treatment of the substrate.
Adapting the distances of the secondary cathode, particularly the second distance
to the substrate may influence the current density distribution. The smaller the second
distance, the more accurately controllable the influence on the current density distribution.
The secondary cathode may be aligned substantially parallel to the distribution body
and/or may be configured to be aligned with the substrate in-line, flush and not outside
the substrate.
[0026] Preferably, the secondary cathode may be configured to be aligned to a main area
of substrate, e.g. a center of substrate, covering at least part of the substrate.
The surface of the secondary cathode may preferably be substantially parallel or angled
to the surface of the substrate to be treated, but not perpendicular.
[0027] The secondary cathode may have approximately the same dimensions as the substrate,
or the dimensions of the secondary cathode can be dynamically adjusted to the substrate
dimensions through turning on and off predefined pixels.
[0028] In a further embodiment, the secondary cathode may be arranged on an inert plate
shield. The inert plate shield may be composed of a chemically inert material. A chemically
inert material may be defined as not chemically reactive in the electrolyte. Therefore,
the inert plate shield may not interfere with the chemical process for plating the
surface of a substrate. When the secondary cathode is arranged on the inert plate
shield, the cathode pixels can also be integrated with the plate shield placed in-between
the primary cathode and the distribution body and can be rotated in cooperation and/or
coordinated with a substrate rotation. Thus, the plate shield may work as a carrier
plate for the cathode pixels allowing a more flexible arrangement of the cathode pixels.
[0029] In an embodiment, the inert plate shield may be attachable to the substrate holder
and movable with the substrate. In particular, this can enable the secondary cathode
to be movable with the substrate, e.g. during loading and unloading into and from
a plating chamber and/or during agitation movements, such as agitation movements with
high as well as with low frequencies, introduced to the substrate. In cases where
the pixels are arranged on or within plate shields, specific arrangements have to
be made for warranting electrical connections to the individual pixels.
[0030] According to the present disclosure, also a distribution module for a process fluid
and an electric current for a chemical and/or electrolytic surface treatment of a
substrate is presented. The distribution module for a process fluid and an electric
current for a chemical and/or electrolytic surface treatment of a substrate comprises
a distribution body as described above, and a substrate holder. The substrate holder
is configured to hold at least one substrate relative to the distribution body.
[0031] This arrangement may enable a localized control and tuning of the current density
distribution, particularly with a tuning resolution down to the sub-µm range. The
individually controllable cathode pixels may enable a very localized adjustment and
tuning of the current density distribution all over a surface of the substrate to
be treated, not only at the edge areas of the substrate. Furthermore, this arrangement
may enable the plating of non-rotating substrates as well as of rotating substrates.
[0032] According to the present disclosure, also a distribution method for a process fluid
and an electric current for a chemical and/or electrolytic surface treatment of a
substrate is presented. The distribution method comprises the following steps, not
necessarily in this order:
- providing a distribution body comprising several openings for the process fluid and
the electric current, wherein the several openings are arranged at a front face of
the distribution body,
- arranging a primary cathode and a secondary cathode to attract and guide the electric
current to the substrate to be treated, wherein the primary cathode is directed to
the front face of the distribution body and wherein the secondary cathode comprises
several cathode pixels distributed in an array aligned with at least an area of the
substrate to be treated, and
- individually controlling the cathode pixels for adjusting a distribution of the electric
current at the substrate.
[0033] This distribution method may enable a localized control and tuning of the current
density distribution, particularly with a tuning resolution down to the sub-µm range.
The individually controllable cathode pixels may enable a very localized adjustment
and tuning of the current density distribution all over a surface of the substrate
to be treated, not only at the edge areas of the substrate. Thus, the distribution
method according to the disclosure may enable the plating of non-rotating substrates
as well as of rotating substrates.
Brief description of the drawings
[0034] Exemplary embodiments of the disclosure will be described in the following with reference
to the accompanying drawings:
- Figure 1
- shows schematically and exemplarily a cross-sectional view of a distribution system
and a distribution module for a process fluid and an electric current for a chemical
and/or electrolytic surface treatment of a substrate, and a substrate according to
an exemplary embodiment.
- Figure 2
- shows schematically and exemplarily a cross-sectional view of a distribution system
and a distribution module for a process fluid and an electric current for a chemical
and/or electrolytic surface treatment of a substrate, and a substrate according to
another exemplary embodiment.
- Figure 3
- shows schematically and exemplarily a cross-sectional view of a distribution system
and a distribution module in a processing bath.
- Figure 4
- shows schematically and exemplarily a flow diagram of a distribution method according
to an exemplary embodiment.
Detailed description of embodiments
[0035] Figure 1 shows schematically and exemplarily an embodiment of a distribution system
1 comprising a distribution body 2, a primary cathode 30 (see Figure 3) and a secondary
cathode 3. The distribution body 2 contains several openings 4, some of which being
formed as jet holes 5 and other being formed as connecting passages 6. The jet holes
5 are smaller than the connecting passages 6 and are configured to direct flow 7 of
a process fluid 18 towards a surface 8 of a substrate 9 to be treated.
[0036] The connecting passages 6 are configured to direct a process fluid 18 (see Figure
3) between a front face 10 of the distribution body 2 and the substrate 9 to flow
towards a rear face 11 of the distribution body 2, illustrated by arrows 12. Thus,
the front face 10 faces the surface 8 of the substrate 9 to be treated. The primary
cathode 30 may be coupled to the substrate 9 as shown in Figure 3, such that the substrate
9 serves as the primary cathode 30 during a treatment process. Figure 1 shows a vertical
mount of the distribution system 1 and the substrate 9, while a horizontal arrangement
would be also possible.
[0037] The secondary cathode 3 comprises several cathode pixels 13, the cathode pixels 13
being arranged on the front face 10 of the distribution body 2 between adjacent openings
4. The cathode pixels 13 are integrated into the front face 10. The integration of
the cathode pixels 13 into the front face 10 of the distribution body 2 is made by
common processes used in the semiconductor and/or flat-panel industry, e.g. photolithography,
or printing.
[0038] The illustration of the cathode pixels 13 is simplified for visibility reasons and
electrical contacts of the cathode pixels 13 as well as electrical connecting lines
connecting the cathode pixels 13 to a power source (not illustrated) are not illustrated.
[0039] Although, the cathode pixels 13 are only illustrated as arranged at the front face
10 of the distribution body 2, the cathode pixels 13 can be arranged additionally
or alternatively on the rear face 11 of the distribution body 2.
[0040] Each cathode pixel 13 is configured to permit an individual controllability of an
electric potential applied by the power source. During the plating process, a cathodic
potential is usually applied, but also the application of an anodic potential is possible,
preferably for achieving an improved pixelated reverse pulse plating or for cleaning
the cathode pixels 13 from potentially deposited metal layers or particles.
[0041] The distribution system 1 in combination with a substrate holder 17 (see Figure 3)
holding the substrate 9 is referred as a distribution module 14.
[0042] Figure 2 shows schematically and exemplarily another embodiment of the distribution
system 1 comprising the distribution body 2, the primary cathode 30 being coupled
to the substrate 9 and/or the substrate holder 17, and the secondary cathode 3. The
distribution body 2 corresponds to the distribution body 2 in Figure 1. The secondary
cathode 3 is separate from the distribution body 2 and arranged on a plate 15. The
plate 15 is positioned between the distribution body 2 and the substrate 9 in a predefined
distance D to the distribution body 2 and in a predefined distance d to the substrate
9. The plate 15 is preferably formed as an inert shield plate 16.
[0043] The cathode pixels 13 are arranged on the plate 15 in a predefined geometric constellation,
which is defined by and aligned with the requirements of an "open area density" distribution
on the substrate. The plate 15 comprising the cathode pixels 13 in a predefined constellation
is placed between the distribution body 2 and the substrate 9 to enable the tuning
of the current density distribution over the whole structured substrate 9.
[0044] The illustration of the cathode pixels 13 is also simplified for visibility reasons
and electrical contacts of the cathode pixels 13 as well as electrical connecting
lines connecting the cathode pixels 13 to a power source (not illustrated) are not
illustrated.
[0045] Figure 3 schematically and exemplarily shows a cross-sectional view of the distribution
system 1 and the distribution module 14 in a processing bath 50. The distribution
body 2 and the substrate 9 being held by the substrate holder 17 are immersed in the
process fluid 18 contained in the processing bath 50. The substrate holder 17 is coupled
to the primary cathode 30 and the primary cathode 30 is coupled with an additional
electrode being an anode 40, wherein the anode 40 is also immersed in the processing
fluid 18 and arranged facing the rear face 11 of the distribution body 2. The processing
fluid 18 is an electrolyte.
[0046] Figure 4 schematically and exemplarily shows a flow diagram of an embodiment of a
distribution method 100 for a process fluid and an electric current for a chemical
and/or electrolytic surface treatment of the substrate 9. The distribution method
100 comprises a step S1 of providing the distribution body 2 comprising the several
openings 4 for the process fluid and the electric current, wherein the several openings
4 are arranged at the front face 10 of the distribution body 2. In a step S2, the
primary cathode and the secondary cathode 3 are arranged to attract and guide the
electric current to the substrate 9 to be treated, wherein the primary cathode is
directed to the front face 10 of the distribution body 2 and wherein the secondary
cathode 3 comprises the several cathode pixels 13 distributed in an array aligned
with at least an area of the substrate 9 to be treated. In a step S3, the cathode
pixels 13 are individually controlled for adjusting a distribution of the electric
current at the substrate 9.
[0047] It has to be noted that embodiments of the invention are described with reference
to different subject matters. In particular, some embodiments are described with reference
to method type claims whereas other embodiments are described with reference to the
device type claims. However, a person skilled in the art will gather from the above
and the following description that, unless otherwise notified, in addition to any
combination of features belonging to one type of subject matter also any combination
between features relating to different subject matters is considered to be disclosed
with this application. However, all features can be combined providing synergetic
effects that are more than the simple summation of the features.
[0048] While the invention has been illustrated and described in detail in the drawings
and foregoing description, such illustration and description are to be considered
illustrative or exemplary and not restrictive. The invention is not limited to the
disclosed embodiments. Other variations to the disclosed embodiments can be understood
and effected by those skilled in the art in practicing a claimed invention, from a
study of the drawings, the disclosure, and the dependent claims.
[0049] In the claims, the word "comprising" does not exclude other elements or steps, and
the indefinite article "a" or "an" does not exclude a plurality. A single unit may
fulfil the functions of several items re-cited in the claims. The mere fact that certain
measures are re-cited in mutually different dependent claims does not indicate that
a combination of these measures cannot be used to advantage. Any reference signs in
the claims should not be construed as limiting the scope.
1. A distribution system (1) for a process fluid (18) and an electric current for a chemical
and/or electrolytic surface treatment of a substrate (9), comprising:
- a distribution body (2),
- a primary cathode (30), and
- a secondary cathode (3),
wherein the distribution body (2) comprises several openings (4) for the process fluid
(18) and the electric current, wherein the several openings (4) are arranged at a
front face (10) of the distribution body (2), wherein the front face (10) is directed
to the primary cathode (30),
wherein the primary cathode (30) and the secondary cathode (3) are arranged to attract
the electric current and to guide the electric current to the substrate (9) to be
treated, wherein the secondary cathode (3) comprises several cathode pixels (13),
wherein the several cathode pixels (13) are distributed in an array to be aligned
with at least an area of the substrate (9) to be treated, and
wherein the several cathode pixels (13) are individually controllable for adjusting
a distribution of the electric current at the substrate (9).
2. The distribution system (1) according to claim 1, further comprising at least a power
source configured to apply individual voltage potentials to the cathode pixels (13)
to individually control the cathode pixels (13).
3. The distribution system (1) according to claim 1 or 2, wherein at least some of the
cathode pixels (13) are each connected to a single power source.
4. The distribution system (1) according to claim 3, wherein at least some cathode pixels
(13) being controlled by the single power source.
5. The distribution system (1) according to any of the claims 2 to 4, further comprising
at least a processing unit configured to control the at least one power source to
apply the individual voltage potentials to the cathode pixels (13) for individual
durations.
6. The distribution system (1) according to any of the preceding claims, wherein the
control for adjusting the distribution of the electric current at the substrate (9)
is a physical arrangement of cathode pixels (13).
7. The distribution system (1) according to any of the preceding claims, wherein the
cathode pixels (13) are arranged at the distribution body (2).
8. The distribution system (1) according to any of the claims 1 to 7, wherein the cathode
pixels (13) are arranged at the front face (10) of the distribution body (1) directed
to the primary cathode (30).
9. The distribution system (1) according to any of the claims 1 to 7, wherein the cathode
pixels (13) are arranged at a rear face (11) of the distribution body (1), wherein
the rear face (11) is opposite to the front face (10) of the distribution body (1).
10. The distribution system (1) according to claim 9, wherein the front face (10) and
the rear face (11) of the distribution body (1) are connected by connecting passages
(6) through the distribution body (1), and wherein the cathode pixels (13) are arranged
at least partially around the connecting passages (6).
11. The distribution system (1) according to any of claims 1 to 6, wherein the secondary
cathode (3) is separate to the distribution body (1) and positioned adjacent to the
distribution body (1) in a direction towards the substrate (9).
12. The distribution system (1) according to any of claims 1 to 6 and 11, wherein the
secondary cathode (3) is arranged on an inert plate shield (16).
13. The distribution system (1) according to the preceding claim, wherein the inert plate
shield (16) is attachable to a substrate holder (17) and movable with the substrate
(9).
14. A distribution module (14) for a process fluid (18) and an electric current for a
chemical and/or electrolytic surface treatment of a substrate (9), comprising:
- a distribution system (1) according to one of the preceding claims, and
- a substrate holder (17),
wherein the substrate holder (17) is configured to hold at least one substrate (9)
relative to the distribution body (2).
15. A distribution method (100) for a process fluid (18) and an electric current for a
chemical and/or electrolytic surface treatment of a substrate (9), comprising:
- providing a distribution body (2) comprising several openings (4) for the process
fluid (18) and the electric current, wherein the several openings (4) are arranged
at a front face (10) of the distribution body (2),
- arranging a primary cathode (30) and a secondary cathode (3) to attract and guide
the electric current to the substrate (9) to be treated, wherein the primary cathode
(30) is directed to the front face (10) of the distribution body (2), and wherein
the secondary cathode (3) comprises several cathode pixels (13) distributed in an
array aligned with at least an area of the substrate (9) to be treated, and
- individually controlling the cathode pixels (13) for adjusting a distribution of
the electric current at the substrate (9).
Amended claims in accordance with Rule 137(2) EPC.
1. A distribution system (1) for a process fluid (18) and an electric current for an
electrolytic surface treatment of a substrate (9), comprising:
- a distribution body (2),
- a primary cathode (30), and
- a secondary cathode (3),
wherein the distribution body (2) comprises several openings (4) for the process fluid
(18) and the electric current, wherein the several openings (4) are arranged at a
front face (10) of the distribution body (2), wherein the front face (10) is directed
to the primary cathode (30),
wherein the primary cathode (30) and the secondary cathode (3) are arranged to attract
the electric current and to guide the electric current to the substrate (9) to be
treated, wherein the secondary cathode (3) comprises several cathode pixels (13),
wherein the several cathode pixels (13) are distributed in an array to be aligned
with at least an area of the substrate (9) to be treated,
wherein the several cathode pixels (13) are individually controllable for adjusting
a distribution of the electric current at the substrate (9), and
wherein the cathode pixels (13) are arranged at the distribution body (2).
2. The distribution system (1) according to claim 1, further comprising at least a power
source configured to apply individual voltage potentials to the cathode pixels (13)
to individually control the cathode pixels (13).
3. The distribution system (1) according to claim 1 or 2, wherein at least some of the
cathode pixels (13) are each connected to a single power source.
4. The distribution system (1) according to claim 3, wherein at least some cathode pixels
(13) being controlled by the single power source.
5. The distribution system (1) according to any of the claims 2 to 4, further comprising
at least a processing unit configured to control the at least one power source to
apply the individual voltage potentials to the cathode pixels (13) for individual
durations.
6. The distribution system (1) according to any of the preceding claims, wherein the
control for adjusting the distribution of the electric current at the substrate (9)
is a physical arrangement of cathode pixels (13).
7. The distribution system (1) according to any of the claims 1 to 6, wherein the cathode
pixels (13) are arranged at the front face (10) of the distribution body (1) directed
to the primary cathode (30).
8. The distribution system (1) according to any of the claims 1 to 6, wherein the cathode
pixels (13) are arranged at a rear face (11) of the distribution body (1), wherein
the rear face (11) is opposite to the front face (10) of the distribution body (1).
9. The distribution system (1) according to claim 8, wherein the front face (10) and
the rear face (11) of the distribution body (1) are connected by connecting passages
(6) through the distribution body (1), and wherein the cathode pixels (13) are arranged
at least partially around the connecting passages (6).
10. The distribution system (1) according to any of claims 1 to 6, wherein the secondary
cathode (3) is separate to the distribution body (1) and positioned adjacent to the
distribution body (1) in a direction towards the substrate (9).
11. The distribution system (1) according to any of claims 1 to 6 and 10, wherein the
secondary cathode (3) is arranged on an inert plate shield (16).
12. The distribution system (1) according to the preceding claim, wherein the inert plate
shield (16) is attachable to a substrate holder (17) and movable with the substrate
(9).
13. A distribution module (14) for a process fluid (18) and an electric current for an
electrolytic surface treatment of a substrate (9), comprising:
- a distribution system (1) according to one of the preceding claims, and
- a substrate holder (17),
wherein the substrate holder (17) is configured to hold at least one substrate (9)
relative to the distribution body (2).
14. A distribution method (100) for a process fluid (18) and an electric current for an
electrolytic surface treatment of a substrate (9), comprising:
- providing a distribution body (2) comprising several openings (4) for the process
fluid (18) and the electric current, wherein the several openings (4) are arranged
at a front face (10) of the distribution body (2),
- arranging a primary cathode (30) and a secondary cathode (3) to attract and guide
the electric current to the substrate (9) to be treated, wherein the primary cathode
(30) is directed to the front face (10) of the distribution body (2), and wherein
the secondary cathode (3) comprises several cathode pixels (13) distributed in an
array aligned with at least an area of the substrate (9) to be treated, and
- individually controlling the cathode pixels (13) for adjusting a distribution of
the electric current at the substrate (9), wherein the cathode pixels (13) are arranged
at the distribution body (2).