TECHNICAL FIELD
[0001] The invention relates to a method for analyzing an object using a charged particle
beam device generating a beam of charged particles. Moreover, the invention relates
to a charged particle beam device for carrying out this method. In particular, the
charged particle beam device is an electron beam device and/or an ion beam device.
BACKGROUND OF THE INVENTION
[0002] Charged particle beam devices are used for analyzing and examining objects (hereinafter
also called samples) in order to obtain insights with regard to the properties and
behavior of the objects under specific conditions. One of those charged particle beam
devices is an electron beam device, in particular a scanning electron microscope (also
known as SEM).
[0003] In an SEM, an electron beam (hereinafter also called primary electron beam) is generated
using a beam generator. The electrons of the primary electron beam are accelerated
to a predeterminable energy and focused by a beam guiding system, in particular an
objective lens, onto a sample to be analyzed (that is to say an object to be analyzed).
A high-voltage source having a predeterminable acceleration voltage is used for acceleration
purposes. Using a deflection unit, the primary electron beam is guided in a raster-type
fashion over a surface of the sample to be analyzed. In this case, the electrons of
the primary electron beam interact with the material of the sample to be analyzed.
In particular, interaction particles and/or interaction radiation arise(s) as a consequence
of the interaction. By way of example, electrons are emitted by the sample to be analyzed
(so-called secondary electrons) and electrons of the primary electron beam are backscattered
at the sample to be analyzed (so-called backscattered electrons). The secondary electrons
and backscattered electrons are detected and used for image generation. An image of
the sample to be analyzed is thus obtained.
[0004] The interaction radiation comprises X-rays and/or cathodoluminescence light and may
be detected with a radiation detector. When measuring X-rays with the radiation detector,
in particular energy-dispersive X-ray spectroscopy (also known as EDS or EDX) may
be carried out. EDX is an analytical analysis method used for the elemental analysis
or chemical characterization. Furthermore, when measuring X-rays with the radiation
detector, in particular wavelength-dispersive X-ray spectroscopy (also known as WDS
or WDX) may be carried out. WDX is also an analytical analysis method used for the
elemental analysis or chemical characterization. EDX and WDX are often used as analytical
analysis methods for analyzing rocks in the field of mineralogy. It is possible to
identify the composition of a mineral grain, which is important information, in particular
for a petrologist who needs to accurately determine the mineralogy of a rock.
[0005] An ion beam device is also known from the prior art. The ion beam device comprises
an ion beam column having an ion beam generator. Ions are generated which are used
for processing a sample (for example for removing a layer of the sample or for depositing
material on the sample, wherein the material is provided by a gas injection system)
or else for imaging.
[0006] Furthermore, it is known from the prior art to use combination devices for processing
and/or for analyzing a sample, wherein both electrons and ions can be guided onto
a sample to be processed and/or to be analyzed. By way of example, it is known for
an SEM to be additionally equipped with an ion beam column as mentioned above. The
SEM serves, in particular, for observing the processing, but also for further analysis
of the processed or non-processed sample. Electrons may also be used for depositing
material. This is known as electron beam induced deposition (EBID). Ions may also
be used for depositing material.
[0007] When analyzing an object with a charged particle beam device, further methods may
be used for identifying characteristics of an object. Electron backscatter diffraction
(also known as EBSD) is a technique used to analyze the crystallographic orientation
and the crystal structure of materials. It is known to use EBSD in an SEM having an
EBSD detector. The EBSD detector may comprise a CCD chip. The EBSD detector detects
electrons backscattered from the object and generates detection signals. Based on
the detection signals, an electron backscatter diffraction pattern (also known as
EBSP) is generated. The EBSP comprises information about Kikuchi bands corresponding
to lattice diffraction planes of an object to be analyzed.
[0008] A further technique for analyzing an object is known as transmission Kikuchi diffraction
(also known as TKD). When using TKD, an electron beam is guided to an object which
is thin enough to be transparent to a sufficient part of the electrons of the electron
beam. In other words, electrons of the electron beam may transmit through the object.
For example, the object is a foil. The object is positioned approximately horizontal
with respect to the sample chamber. Alternatively, the object is slightly tilted away
from the EBSD detector by an angle of up to 20° or up to 30°. The scattered and transmitted
electrons of the electron beam emerging from a bottom side of the object are detected
using the EBSD detector. The EBSD detector is positioned off-axis with respect to
the optical axis of the electron beam guided to the object. In particular, the EBSD
detector is positioned below the object and below a position which is normally used
for EBSD when generating an EBSP as mentioned above. Using TKD, the EBSD detector
generates detector signals used for acquiring and recording diffraction patterns of
the object, the diffraction patterns being projected from the bottom side of the object
to the EBSD detector.
[0009] EDX, WDX and EBSD are limited with respect to their analytical resolution by the
sampling volume, wherein the resolution is about 1 µm, as explained further below.
The landing energy of electrons of an SEM used for EDX, WDX and EBSD is often chosen
in such a way that the electrons penetrate rather deep into the object and generate
X-rays from a volume unit of the object comprising an extension of about 1 µm in a
first direction, in a second direction and in a third direction. Therefore, the volume
unit comprises dimensions of approximately 1 µm × 1 µm × 1 µm. However, this resolution
may not be sufficient for analysis of materials, in particular in oil and gas applications
since, for example, sedimentary rocks may comprise features of interest having a dimension
much smaller than 1 µm.
[0010] A charged particle beam device such as a combination of an SEM with an ion beam column
may be used to generate high resolution 3D data sets by sequentially removing material
from the object, exposing a surface of the object and generating an image of the surface.
The resolution of the image may be 1 nm to 3 nm. Unfortunately, as mentioned above,
the analytical methods such as EDX, WDX and EBSD do not offer a resolution in nm-range,
thus making it difficult to generate high resolution 3D analytical data sets obtained
by EDX, WDX and EBSD. With respect to the prior art it is referred to
US 2015/0214004 A1 which discloses a method for analyzing an object using a charged particle beam device.
The charged particle beam device comprises a first charged particle beam generator
(ion source), a second beam generator (field emitter of a SEM), the method comprising
removing material with a focused ion beam of the ion source, while imaging, using
the electron beam of the SEM and a first detector, at least a first surface of the
object and a second surface subsequently exposed by said removing material; thereby
generating an opening and a lamella having the exposed second surface as an outer
surface, and analysing the material of the lamella using a second detection unit.
[0011] It is desirable to provide a method for analyzing an object using a charged particle
beam device and a charged particle beam device for carrying out the method which make
it possible to obtain a high resolution 3D analytical data set based on analysis methods
such as, for example, EDX, WDX and EBSD.
SUMMARY OF THE INVENTION
[0012] According to the invention, this is solved by a method according to claim 1. A computer
program product comprising a program code for controlling a charged particle beam
device is given by the features of claim 9. The charged particle beam device for carrying
out the method is given by claim 10. Further features of the invention are evident
from the following description, the following claims and/or the accompanying figures.
[0013] The method according to the invention is used for analyzing an object using a charged
particle beam device, for example an electron beam device and/or an ion beam device.
The charged particle beam device may comprise a first charged particle beam generator
for generating a first charged particle beam having first charged particles. The first
charged particles may be electrons and/or ions. Moreover, the charged particle beam
device may comprise a first objective lens for focusing the first charged particle
beam onto the object. Additionally, the charged particle beam device may comprise
a second charged particle beam generator for generating a second charged particle
beam having second charged particles. The second charged particles may be electrons
and/or ions. Moreover, the charged particle beam device may comprise a second objective
lens for focusing the second charged particle beam onto the object. Moreover, the
charged particle beam device may comprise a first detection unit for detecting interaction
particles and a second detection unit for detecting interaction particles and/or interaction
radiation, the interaction particles and the interaction radiation arising when the
first charged particle beam and/or the second charged particle beam impinge(s) on
the object.
[0014] The interaction particles may be secondary particles, for example secondary electrons
or secondary ions, or backscattered particles, for example backscattered electrons.
The interaction radiation may be X-rays or cathodoluminescence light.
[0015] The charged particle beam device may be used to generate high resolution 3D data
sets by sequentially removing material from the object, exposing a surface of the
object and generating an image of the surface. The resolution of the image may be
1 nm to 3 nm. More precisely, the method according to the invention may comprise the
following steps:
- guiding the first charged particle beam over the object and removing material from
the object using the first charged particle beam. When removing the material from
the object, a first surface of the object is exposed;
- guiding the second charged particle beam over the first surface of the object, detecting
interaction particles using the first detection unit, wherein the interaction particles
arise when the second charged particle beam impinges on the first surface. A first
detection signal is generated using the first detection unit and a first image of
the first surface of the object is generated using the first detection signal. The
first image comprises first image pixels, each pixel of the first image pixels comprising
first image data;
- guiding the first charged particle beam over the object and removing material - including
said first surface - from the object using the first charged particle beam. When removing
the material, a second surface of the object is exposed; and
- guiding the second charged particle beam over the second surface of the object. Interaction
particles are detected using the first detection unit, the interaction particles arising
when the second charged particle beam impinges on the second surface. A second detection
signal is generated using the first detection unit. A second image of the second surface
is generated using the second detection signal, the second image comprising second
image pixels, each pixel of the second image pixels comprising second image data.
[0016] When removing the material from the object for exposing the first surface and the
second surface of the object, an opening is generated in the object, in particular
when the method steps mentioned above are sequentially repeated. The opening comprises
a first side comprising the second surface and a second side extending from the second
surface of the object in a direction away from the second surface.
[0017] The method according to the invention comprises a step of generating lamellas comprising
the sides of the opening and of identifying the material characteristics of those
lamellas. More precisely, the method according to the invention comprises the following
steps:
- generating a first lamella comprising the first side of the opening having the second
surface as an outer surface. In other words, the first lamella comprising the first
side is cut out of the object. The first charged particle beam and/or the second charged
particle beam may be used for generating the first lamella;
- generating a second lamella comprising at least a part of the second side of the opening.
In other words, the second lamella comprising the second side is cut out of the object.
The first charged particle beam and/or the second charged particle beam may be used
for generating the second lamella;
- guiding the second charged particle beam over the second side of the object, detecting
interaction particles using the first detection unit, wherein the interaction particles
arise when the second charged particle beam impinges on the second side of the object.
Moreover, a third detection signal is generated using the first detection unit. Additionally,
a third image of the second side of the object is generated using the third detection
signal. The third image comprises third image pixels, each pixel of the third image
pixels comprising third image data;
- analyzing the first lamella by identifying first material characteristics of the first
lamella associated to each pixel of the second image pixels using the first charged
particle beam and/or the second charged particle beam and detecting interaction particles
and/or interaction radiation using the second detection unit. In other words, the
material characteristics of the object are identified for each particular pixel of
the second image pixels. The material characteristics may comprise, for example, a
material composition, a quantity of a specific element and/or a size of a specific
element; and
- analyzing the second lamella by identifying second material characteristics of the
second lamella associated to each pixel of the third image pixels using the first
charged particle beam and/or the second charged particle beam and detecting interaction
particles and/or interaction radiation using the second detection unit. In other words,
the material characteristics of the object are identified for each particular pixel
of the third image pixels. The material characteristics may comprise, for example,
a material composition, a quantity of a specific element and/or a size of a specific
element.
[0018] The first lamella and/or the second lamella may have a thickness in the range of
10 nm to 100 nm or in the range of 30 nm to 50 nm. However, the invention is not restricted
to the aforementioned ranges. Rather, the thickness may have any value suitable for
the invention.
[0019] The method according to the invention comprises the step of generating filtered data
for each pixel of the second image pixels and the third image pixels. More precisely,
the method according to the invention comprises the following steps:
- generating first filtered data of each pixel of the second image pixels using at least
one first image filter for processing the second image data for each pixel of the
second image pixels; and
- generating second filtered data of each pixel of the third image pixels using at least
one second image filter for processing the third image data for each pixel of the
third image pixels.
[0020] In other words, each pixel of the second image pixels and/or each pixel of the third
image pixels is/are filtered using the at least one first and one second image filters.
Filtered data is generated associated to each pixel of the second image pixels and
of the third image pixels. The at least one first image filter and/or the at least
one second image filter may be a digital image filter, as explained further below.
Optionally, the first image filter and the second image filter are identical.
[0021] The method according to the invention now uses the information with respect to the
identified material characteristics and the filtered data to obtain information on
the material characteristics for each pixel of each surface generated when sequentially
removing material from the object. More precisely, the method according to the invention
also comprises the following steps:
- identifying data identical or similar to the first image data of each pixel of the
first image pixels of the first image from among the following: the second image data
of each pixel of the second image pixels, the third image data of each pixel of the
third image pixels, the first filtered data for each pixel of the second image pixels
and the second filtered data for each pixel of the third image pixels. The data is
considered to be similar to the first image data of each pixel of the first image
pixels of the first image if a calculation based on probability reveals that this
data comes closest to the first image data of each pixel of the first image pixels;
and
- assigning material characteristics to at least one pixel of the first image pixels
of the first image, wherein:
- (i) the first material characteristics are assigned if at least one of: the identified
second image data of a pixel of the second image pixels and the identified first filtered
data for a pixel of the second image pixels is identical or similar to the first image
data of the at least one pixel of the first image pixels; and wherein
- (ii) the second material characteristics are assigned if at least one of:
the identified third image data of a pixel of the third image pixels and the identified
second filtered data for a pixel of the third image pixels is identical or similar
to the first image data of the at least one pixel of the first image pixels.
[0022] The method according to the invention provides for obtaining a high resolution 3D
analytical data set based on analysis methods such as, for example, EDX, WDX, EBSD
and TKD. In particular, the above mentioned method combines the high resolution of
an image obtained using a charged particle beam device such as an SEM and the data
obtained when analyzing a lamella using analysis methods such as, for example, EDX,
WDX, EBSD and TKD. The high resolution analytical capability is improved by generating
the first lamella and the second lamella which may be as thin as a TEM lamella generated
from a bulk object known from the prior art. In particular, analysis methods such
as EDX and/or WDX may be used when analyzing the lamella to quantify and identify
material characteristics such as, for example, the composition of the material of
the lamella, in particular existing mineralogy and phases. Phases and crystal orientations
may be determined by TKD and/or EBSD. Since the first lamella and the second lamella
are thin, most particles of the charged particle beam used for the above mentioned
analysis methods and impinging on the first lamella and on the second lamella transmit
through the lamella. X-rays are generated in a rather small volume, such as 10 nm
x 10 nm x 10 nm, in comparison to a bulk object used in the prior art, the bulk object
having a volume of, for example, 1000 nm x 1000 nm x 1000 nm. Accordingly, the data
sets generated when using the above mentioned analysis methods on the thin first lamella
and thin second lamella provide a high resolution, for example 10 nm.
[0023] Moreover, the method according to the invention provides for a fast identification
of material characteristics of surfaces of slices obtained by removing material from
an object. The method according to the invention does not provide for analysis of
each exposed surface when removing material from the object. Instead, images of each
exposed surface are generated, and sides of an opening are analyzed with respect to
the material characteristics, using lamellas comprising the sides. The data obtained
from analyzing the sides is used to identify the material characteristics of each
exposed surface by calculation.
[0024] Any method which is suitable for identifying data which are identical or similar
to the first image data for each pixel of the first image pixels of the first image
may be used. A machine learning segmentation (wherein the segmentation is a classification)
may be one of those methods. The machine learning segmentation may be a classifier.
Therefore, the image data of each surface may be classified (that is identified and
assigned to a specific material characteristic) using the machine learning segmentation.
The machine learning segmentation provides proper classification of each pixel of
the images of the obtained surfaces and properly identifies grain boundary and texture.
As the classification - that means the segmentation - is performed on high resolution
images, the obtained classified volume of a slice comprising a specific surface retains
the high resolution of the images.
[0025] It is additionally or alternatively provided in an embodiment of the method according
to the invention that the method may further comprise a step of generating a further
lamella comprising a side of the opening and of identifying the material characteristics
of this lamella. More precisely, the method according to the invention may comprise
the following steps:
- generating a third lamella having a third side of the opening, the third side and
the second side being arranged opposite to each other and the first side being arranged
between the second side and the third side;
- guiding the second charged particle beam over the third side of the object, detecting
interaction particles using the first detection unit, the interaction particles arising
when the second charged particle beam impinges on the third side of the object. Moreover,
a fourth detection signal is generated using the first detection unit and a fourth
image of the third side of the object is generated using the fourth detection signal.
The fourth image comprises fourth image pixels, each pixel of the fourth image pixels
comprising fourth image data;
- analyzing the third lamella by identifying third material characteristics of the third
lamella associated to each pixel of the fourth image pixels using the first charged
particle beam and the second charged particle beam, respectively, and detecting interaction
particles and/or interaction radiation using the second detection unit; and
- generating third filtered data for each pixel of the fourth image pixels using at
least one third image filter for processing the fourth image data for each pixel of
the fourth image pixels.
[0026] Moreover, the step of identifying data identical or similar to the first image data
for each pixel of the first image pixels of the first image also comprises identifying
data from among the following: the fourth image data of each pixel of the fourth image
pixels and the third filtered data for each pixel of the fourth image pixels. The
step of assigning material characteristics to at least one pixel of the first image
pixels of the first image also comprises assigning the third material characteristics
if the identified fourth image data of a pixel of the fourth image pixels and/or the
identified third filtered data for a pixel of the fourth image pixels is/are identical
or similar to the first image data of the at least one pixel of the first image pixels.
[0027] It is additionally or alternatively provided in an embodiment of the method according
to the invention that the step of identifying identical or similar data comprises
comparing the first image data for each pixel of the first image pixels of the first
image to at least one of: the second image data of each pixel of the second image
pixels, the third image data of each pixel of the third image pixels, the fourth image
data of each pixel of the fourth image pixels, the first filtered data for each pixel
of the second image pixels, the second filtered data for each pixel of the third image
pixels and the third filtered data for each pixel of the fourth image pixels.
[0028] It is additionally or alternatively provided in an embodiment of the method according
to the invention that the method may comprise analyzing the first lamella, the second
lamella and/or the third lamella using X-rays and/or cathodoluminescence light.
[0029] It is additionally or alternatively provided in a further embodiment of the method
according to the invention that the method may further comprise analyzing the first
lamella, the second lamella and/or the third lamella using EDX, WDX, EBSD and/or TKD.
[0030] It is additionally or alternatively provided in an embodiment of the method according
to the invention that the step of identifying identical or similar data comprises
using a learning method for classification. In particular, one of the following methods
may be used: a random decision forest, association rule learning, an artificial neural
network, a support vector machine and a Bayesian network. The aforementioned methods
are machine learning methods for classification, wherein classification is the problem
of identifying to which of a set of categories a new set of data belongs.
[0031] It is additionally or alternatively provided in an embodiment of the method according
to the invention that the method may further comprise using at least one of the following
filters as the first image filter, the second image filter or the third image filter:
a Gabor filter, a mean filter, a variance filter, a histogram oriented gradient filter,
a maximum filter, a minimum filter and a Kuwahara filter. A Gabor filter is a band
pass filter for texture analysis. A mean filter is a method of smoothing images thereby
reducing the amount of intensity variation between two pixels. A variance filter,
a maximum filter and a minimum filter are also known in the art. A Kuwahara filter
is a nonlinear smoothing filter used in image processing for adaptive noise reduction.
[0032] The invention also refers to a computer program product comprising a program code
which is adapted to be loaded into a processor and which, when being executed, controls
a charged particle beam device in such a way that a method comprising the steps according
to claim 1 is carried out.
[0033] The invention also refers to a charged particle beam device for analyzing an object.
The charged particle beam device may comprise a first charged particle beam generator
for generating a first charged particle beam having first charged particles. The first
charged particles may be electrons and/or ions. The charged particle beam device may
also have a first objective lens for focusing the first charged particle beam onto
the object. Moreover, the charged particle beam device may comprise a second charged
particle beam generator for generating a second charged particle beam having second
charged particles. The second charged particles may be electrons and/or ions. A second
objective lens for focusing the second charged particle beam onto the object is provided.
Moreover, the charged particle beam device may comprise a first detection unit for
detecting interaction particles and a second detection unit for detecting interaction
particles and/or interaction radiation, the interaction particles and the interaction
radiation arising when at least one of: (i) the first charged particle beam and (ii)
the second charged particle beam impinges on the object. Moreover, the charged particle
beam device may comprise at least one processor into which a computer program product
as the one mentioned above is loaded.
[0034] In an embodiment of the above mentioned charged particle beam device according to
the invention, it is additionally or alternatively provided that a first detector
comprises the first detector unit and a second detector comprises the second detector
unit. Thus, the two detector units are arranged in different detectors. In an alternative
embodiment a single detector comprises the first detector unit and the second detector
unit.
[0035] In an embodiment of the above mentioned charged particle beam device according to
the invention, it is additionally or alternatively provided that the charged particle
beam device may be at least one of the following: an electron beam device and an ion
beam device. In particular, the charged particle beam device may be both an electron
beam device and an ion beam device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Embodiments of the invention described herein will be explained in more detail in
the following text with reference to the figures, in which:
- Fig. 1
- shows a schematic representation of an embodiment of a charged particle beam device;
- Fig. 2
- shows a further schematic representation of the charged particle beam device according
to Figure 1;
- Fig. 3
- shows a schematic representation of a charged particle beam device which is an example
being not part of the invention, but which is useful for understanding the invention;
- Fig. 4
- shows a schematic representation of an embodiment of a first part of a method according
to the invention;
- Fig. 5
- shows a schematic representation of a first part of a method which is an example being
not part of the invention, but which is useful for understanding the invention;
- Fig. 6
- is a schematic representation of an object, a first particle beam column and a second
particle beam column;
- Figs. 7A-7C
- are schematic representations of lamellas;
- Fig. 8
- shows a second part of a method according to the invention;
- Figs. 9A-9I
- show filtered images of a surface of an object;
- Fig. 10
- is an image of a surface used as a training image for a random decision forest;
- Fig. 11A
- is a schematic representation of a training phase of a random decision forest;
- Fig. 11B
- is a schematic representation of a decision tree in the training phase of a random
decision forest;
- Fig. 12
- is a schematic representation of a validation phase of a random decision forest; and
- Fig. 13
- is a schematic representation of a classification phase of a random decision forest.
[0037] Figure 1 shows a schematic illustration of a first embodiment of a charged particle beam device
300 according to the invention. The charged particle beam device 300 has a first particle
beam column 301 in the form of an ion beam column, and a second particle beam column
302 in the form of an electron beam column. The first particle beam column 301 and
the second particle beam column 302 are arranged on an object chamber 303, in which
an object 304 to be analyzed and/or processed is arranged. It is explicitly noted
that the system described herein is not restricted to the first particle beam column
301 being in the form of an ion beam column and the second particle beam column 302
being in the form of an electron beam column. In fact, the system described herein
also provides for the first particle beam column 301 to be in the form of an electron
beam column and for the second particle beam column 302 to be in the form of an ion
beam column. A further embodiment of the system described herein provides for both
the first particle beam column 301 and the second particle beam column 302 each to
be in the form of an ion beam column.
[0038] Figure 2 shows a detailed illustration of the charged particle beam device 300 shown in
Figure 1. For clarity reasons, the object chamber 303 is not illustrated. The first particle
beam column 301 in the form of the ion beam column has a first optical axis 305. Furthermore,
the second particle beam column 302 in the form of the electron beam column has a
second optical axis 306.
[0039] The second particle beam column 302, in the form of the electron beam column, will
be described next. The second particle beam column 302 has a second beam generator
307, a first electrode 308, a second electrode 309 and a third electrode 310. By way
of example, the second beam generator 307 is a thermal field emitter. The first electrode
308 has the function of a suppressor electrode, while the second electrode 309 has
the function of an extractor electrode. The third electrode 310 is an anode, and at
the same time forms one end of a beam guide tube 311.
[0040] A second charged particle beam 312 in the form of an electron beam is generated by
the second beam generator 307. Electrons which emerge from the second beam generator
307 are accelerated to the anode potential, for example in the range from 1 kV to
30 kV, as a result of a potential difference between the second beam generator 307
and the third electrode 310. The second charged particle beam 312 in the form of the
electron beam passes through the beam guide tube 311, and is focused onto the object
304 to be analyzed and/or processed. This will be described in more detail further
below.
[0041] The beam guide tube 311 passes through a collimator arrangement 313 which has a first
annular coil 314 and a yoke 315. Seen in the direction of the object 304, from the
second beam generator 307, the collimator arrangement 313 is followed by a pin hole
diaphragm 316 and a detector 317 with a central opening 318 arranged along the second
optical axis 306 in the beam guide tube 311. In a further embodiment, the opening
318 may be not centered.
[0042] The beam guide tube 311 then runs through a hole in a second objective lens 319.
The second objective lens 319 is used for focusing the second charged particle beam
312 onto the object 304. For this purpose, the second objective lens 319 has a magnetic
lens 320 and an electrostatic lens 321. The magnetic lens 320 is provided with a second
annular coil 322, an inner pole piece 323 and an outer pole piece 324. The electrostatic
lens 321 comprises an end 325 of the beam guide tube 311 and a terminating electrode
326.
[0043] The end 325 of the beam guide tube 311 and the terminating electrode 326 concurrently
form an electrostatic deceleration device. The end 325 of the beam guide tube 311,
together with the beam guide tube 311, is at the anode potential, while the terminating
electrode 326 and the object 304 are at a potential which is lower than the anode
potential. This allows the electrons of the second charged particle beam 312 to be
decelerated to a desired energy which is required for examination of the object 304.
[0044] The second particle beam column 302 furthermore has a raster device 327, by which
the second charged particle beam 312 can be deflected and can be scanned in the form
of a raster over the object 304.
[0045] For imaging purposes, the detector 317, which is arranged in the beam guide tube
311, detects secondary electrons and/or backscattered electrons, which result from
the interaction between the second charged particle beam 312 and the object 304. The
signals generated by the detector 317 are transmitted to a control unit 700.
[0046] A further particle detector 703 is arranged in the object chamber 303 (see
Figure 1). The particle detector 703 detects secondary electrons and/or backscattered electrons,
which result from the interaction between the second charged particle beam 312 and
the object 304. The signals generated by the particle detector 703 are transmitted
to the control unit 700.
[0047] A further detector, namely an EBSD detector 336, is arranged in the object chamber
303. The EBSD detector 336 is positioned off-axis with respect to the second optical
axis 306 of the second particle beam column 302. The EBSD detector 336 may be positioned
in a first position Pos A above the object 304. In a second position Pos B, the EBSD
detector 336 is positioned below the object 304 (see
Figure 1).
[0048] Interaction radiation, for example X-rays or cathodoluminescence light, may be detected
by using a radiation detector 500, for example a CCD-detector, which is arranged in
the object chamber 303 (see
Figure 1). The radiation detector 500 is positioned at the side of the object 304 and is directed
to the object 304.
[0049] The object 304 is arranged on an object holder 328 in the form of a sample stage
as shown in
Figure 1, by which the object 304 is arranged such that it can move along three axes which
are arranged to be mutually perpendicular (specifically an x-axis, a y-axis and a
z-axis). Furthermore, the sample stage can be rotated about two rotation axes which
are arranged to be mutually perpendicular. It is therefore possible to move the object
304 to a desired position. The rotation of the object holder 328 about one of the
two rotation axes may be used to tilt the object holder 328 such that the surface
of the object 304 may be oriented perpendicular to the second charged particle beam
312 or to a first charged particle beam 329. Alternatively, the surface of the object
304 may be oriented in such a way that the surface of the object 304 on one hand and
the first charged particle beam 329 or the second charged particle beam 312 on the
other hand are at an angle, for example in the range of 0° to 90°.
[0050] As mentioned previously, reference symbol 301 denotes the first particle beam column,
in the form of the ion beam column. The first particle beam column 301 has a first
beam generator 330 in the form of an ion source. The first beam generator 330 is used
for generating the first charged particle beam 329 in the form of an ion beam. Furthermore,
the first particle beam column 301 is provided with an extraction electrode 331 and
a collimator 332. The collimator 332 is followed by a variable aperture 333 in the
direction of the object 304 along the first optical axis 305. The first charged particle
beam 329 is focused onto the object 304 by a first objective lens 334 in the form
of a focusing lens. Raster electrodes 335 are provided in order to scan the first
charged particle beam 329 over the object 304 in the form of a raster.
[0051] When the first charged particle beam 329 strikes the object 304, the first charged
particle beam 329 interacts with the material of the object 304. In the process, interaction
radiation is generated and detected using the radiation detector 500. Interaction
particles are generated, in particular secondary electrons and/or secondary ions.
These are detected using the detector 317.
[0052] The object chamber 303 is operated in a first pressure range or in a second pressure
range, wherein the first pressure range only comprises pressures lower than or equal
to 10
-3 hPa and wherein the second pressure range only comprises pressures over 10
-3 hPa. A pressure sensor 600 is arranged in the object chamber 303 for measuring the
pressure in the object chamber 303 (see
Figure 1). A pump system 601 connected to the pressure sensor 600 and arranged at the object
chamber 303 provides for the pressure range in the object chamber 303, either the
first pressure range or the second pressure range.
[0053] The first charged particle beam 329 may also be used to process the object 304. For
example, material may be deposited on the surface of the object 304 using the first
charged particle beam 329, wherein the material is provided with a gas injection system
(GIS). Additionally or alternatively, structures may be etched into the object 304
using the first charged particle beam 329. Moreover, the second charged particle beam
312 may be used to process the object 304, for example by electron beam induced deposition.
[0054] The detector 317, the EBSD detector 336, the radiation detector 500 and the particle
detector 703 are connected to the control unit 700 as shown in
Figures 1 and 2. The control unit 700 comprises a processor 701 into which a computer program product
comprising a program code is loaded, which, when being executed, controls the charged
particle beam device 300 in such a way that a method according to the invention is
carried out. This will be explained further below. Moreover, the control unit 700
may comprise a database 702.
[0055] Figure 3 shows a schematic illustration of a charged particle beam device 300 which is an
example being not part of the invention, but which is useful for understanding the
invention. The example of
Figure 3 is based on the embodiment of
Figures 1 and 2. Therefore, like reference signs denote like parts. However, the example of
Figure 3 does not comprise the first particle beam column 301, but it comprises the second
particle beam column 302. Moreover, the example of
Figure 3 comprises a gas injection unit 337 providing gas to the object 304. The gas may be
a reactive gas such as, for example, Cl
2, I
2, SiF
4, CF
4, NF
3, N
2O, NH
3+O
2, NO
2, H
2O or XeF
2. However, the example is not restricted to the aforementioned examples.
[0056] An embodiment of a method according to the invention will now be explained. The method
is carried out with the charged particle beam device 300 according to
Figures 1 and 2. Figure 4 shows a first part of the embodiment of the method. This first part comprises, in
particular, generating high resolution 3D data sets by sequentially removing material
from the object 304, exposing a surface of the object 304 and generating an image
of the surface. The resolution of the image may be 1 nm to 3 nm. More precisely, the
first charged particle beam 329 in the form of the ion beam is guided over the object
304 in method step S1. Material is removed from the object 304 when guiding the first
charged particle beam 329 over the object 304 (see method step S2). This is schematically
shown in
Figure 6. Figure 6 is a schematic representation of the object 304, the first particle beam column 301
in the form of an ion beam column and the second particle beam column 302 in the form
of the electron beam column. When removing material from the object 304, a first surface
800 is exposed. In method step S3, the second charged particle beam 312 in the form
of the electron beam is guided over the exposed first surface 800. The second charged
particle beam 312 interacts with the material of the exposed first surface 800. Secondary
electrons and/or backscattered electrons arise from the interaction. The detector
317 or the particle detector 703 detects those secondary electrons and/or backscattered
electrons and generates a first detection signal which is transmitted to the control
unit 700. A first image of the exposed first surface 800 is generated using the first
detection signal (method step S4). In method step S5, the generated first image is
stored in the database 702.
[0057] In method step S6, it is decided whether further material is to be removed from the
object 304. In the affirmative, method steps S1 to S5 are repeated and a further surface
is exposed. In other words, the first charged particle beam 329 is guided over the
object 304 again. Material of the object 304 comprising the first surface 800 is removed
from the object 304 when guiding the first charged particle beam 329 over the object
304. When removing material, including the first surface 800, a further surface, namely
a second surface 801, is exposed (see
Figure 6). An image of the second surface 801 is now generated. The second charged particle
beam 312 is guided over the exposed second surface 801. The second charged particle
beam 312 interacts with the material of the exposed second surface 801. Secondary
electrons and/or backscattered electrons arise from the interaction. The detector
317 or particle detector 703 detects those secondary electrons and/or backscattered
electrons and generates a second detection signal which is transmitted to the control
unit 700. A second image of the exposed second surface 801 is generated using the
second detection signal. The generated second image is stored in the database 702.
[0058] It is again decided in method step S6 whether further material is to be removed from
the object 304. In the affirmative, method steps S1 to S5 are repeated again and a
further surface is exposed. In other words, material of the object 304 is removed
from the object 304 slice by slice, wherein each time a slice is removed, a new surface
is exposed and imaged. The image of each exposed surface is stored in the database
702. Therefore, method steps S1 to S6 provide for generating high resolution 3D data
sets by sequentially removing material from the object 304, exposing surfaces of the
object 304 and generating images of the surfaces. For example, up to 1,000 surfaces
may be exposed and images of each of the 1,000 surfaces are stored in the database
702. However, the invention is not restricted to this number of surfaces. Rather,
any suitable number of surfaces may be exposed and imaged.
[0059] As shown in
Figure 6, an opening 803 is generated when removing material from the object 304 and when exposing
the surfaces, in particular the first surface 800 and the second surface 801. The
opening 803 is bordered by a boundary side 804, a first side 805 and a second side
806. The boundary side 804 may be a bottom side of the opening 803. Therefore, the
boundary side 804 comprises the last surface to be exposed when material is removed
from the object 304. In the embodiment as shown in
Figure 6, the boundary side 804 comprises the second surface 801. However, the invention is
not restricted to the boundary side 804 always comprising the second surface 801.
Rather, the boundary side 804 may comprise any surface being the last surface to be
exposed when material is removed from the object 304.
[0060] The first side 805 extends from the boundary side 804 in a first direction away from
the boundary side 804. Moreover, the second side 806 also extends from the boundary
side 804 of the object 304 in a second direction away from the boundary side 804.
The first direction and the second direction may be identical or may be different.
The first side 805 and the second side 806 are arranged opposite to each other. Moreover,
the boundary side 804 is arranged between the first side 805 and the second side 806.
The boundary side 804, the first side 805 and the second side 806 may form a U-shape
(similar to the letter U), the boundary side 804 being the bottom part of the "U",
and the first side 805 and the second side 806 being the side pieces of the "U".
[0061] In method step S7, a first lamella 807, a second lamella 808 and, optionally, a third
lamella 809 are generated using the first charged particle beam 329. The first lamella
807, the second lamella 808 and the third lamella 809 are schematically shown in
Figures 7A to 7C. They are generated by cutting them out of the object 304 using the first charged
particle beam 329. The first lamella 807, the second lamella 808 and the third lamella
809 may be arranged at a holder (not shown) for further analysis. The holder is part
of the charged particle beam device 300 and is arranged in the object chamber 303.
The first lamella 807 is a boundary lamella. It comprises the boundary side 804 and,
thus, the last surface to be exposed when material is removed from the object. In
the embodiment shown in
Figure 6, this is the second surface 801. The second lamella 808 is a side lamella. It comprises
the first side 805. The third lamella 809 is also a side lamella. It comprises the
second side 806. The first lamella 807 may have a thickness T1, the second lamella
808 may have a thickness T2 and/or the third lamella 809 may have a thickness T3.
The thicknesses T1 to T3 may be identical or may differ from each other. In particular,
each of the thicknesses T1 to T3 may be in the range of 10 nm to 100 nm or in the
range of 30 nm to 50 nm. However, the invention is not restricted to the aforementioned
ranges. Rather, each of the thicknesses T1 to T3 may have any value suitable for the
invention.
[0062] As mentioned above, the images of the surfaces exposed are generated and stored.
In particular, the last surface to be exposed is generated and imaged. In the embodiment
of
Figure 6, this surface is the second surface 801. In a further method step S8, images of the
second lamella 808 and the third lamella 809 are also generated. The second charged
particle beam 312 in the form of the electron beam is guided over the first side 805,
which is one of the outer surfaces of the second lamella 808. The second charged particle
beam 312 interacts with the material of the first side 805. Secondary electrons and/or
backscattered electrons arise from the interaction. The detector 317 or the particle
detector 703 detects those secondary electrons and/or backscattered electrons and
generates a third detection signal which is transmitted to the control unit 700. A
third image of the first side 805 is generated using the third detection signal. The
generated third image is stored in the database 702. Moreover, the second charged
particle beam 312 in the form of the electron beam is guided over the second side
806, which is one of the outer surfaces of the third lamella 809. The second charged
particle beam 312 interacts with the material of the second side 806. Secondary electrons
and/or backscattered electrons arise from the interaction. The detector 317 or the
particle detector 703 detects those secondary electrons and/or backscattered electrons
and generates a fourth detection signal which is transmitted to the control unit 700.
A fourth image of the second side 806 is generated using the fourth detection signal.
The generated fourth image is stored in the database 702.
[0063] An example of a further method will now be explained. The further method is carried
out with the charged particle beam device 300 according to
Figure 3. Figure 5 shows a first part of the example of the method, wherein the example is not part
of the invention, but useful for the understanding the invention. This first part
comprises, in particular, generating high resolution 3D data sets by sequentially
removing material from the object 304, exposing a surface of the object 304 and generating
an image of the surface. The resolution of the image may be 1 nm to 3 nm. The first
part of the example of the further method according to
Figure 5 is based on the embodiment of
Figure 4. Therefore, the aforementioned explanation with respect to the embodiment of
Figure 4 also applies to the example of
Figure 5. However, instead of method steps S1 and S3, the example of
Figure 5 comprises method steps S1A and S3A. In method step S1A, the second charged particle
beam 312 in the form of the electron beam is guided over the object 304. Furthermore,
gas is provided by the gas injection unit 337. In method step S2, material is removed
from the object 304 using the second charged particle beam 312 and the gas by etching
material from the object 304. The first surface 800 of the object 304 is exposed,
as explained above. In method step S3A, the second charged particle beam 312 in the
form of the electron beam is guided over the exposed first surface 800. The second
charged particle beam 312 interacts with the material of the exposed first surface
800. Secondary electrons and/or backscattered electrons arise from the interaction.
The detector 317 or the particle detector 703 detects those secondary electrons and/or
backscattered electrons and generates a first detection signal which is transmitted
to the control unit 700. A first image of the exposed first surface 800 is generated
using the first detection signal and is stored in the database. The method steps S1A
to S5 are repeated if necessary and as explained above.
[0064] The example of
Figure 5 also comprises one difference in method step S7 with respect to the embodiment of
Figure 4. As mentioned above, the first lamella 807, the second lamella 808 and the third lamella
809 are generated in method step S7. However, rather than using the first charged
particle beam 329, the first lamella 807, the second lamella 808 and the third lamella
809 are generated by cutting them out of the object 304 by an etching process using
the second charged particle beam 312 and the gas provided by the gas injection unit
337.
[0065] Figure 8 shows a second part of each of the above mentioned methods, comprising further method
steps for the embodiment of
Figure 4 and the example shown in
Figure 5.
[0066] In method step S9, material characteristics of the generated lamellas are determined.
More precisely, in method step S9, the first lamella 807 (i.e. the boundary lamella),
the second lamella 808 and the third lamella 809 are analyzed with respect to their
material characteristics using the second charged particle beam 312. In other words,
an analysis is carried out to identify the material and/or the composition of elements
each lamella has at a particular pixel in its respective image. The material characteristics
may also comprise, for example, information about the quantity of a specific element
and/or its size and/or its structure contained in the material.
[0067] The first lamella 807 is analyzed by identifying first material characteristics of
each pixel of the second image pixels of the second image, namely the image of the
second surface 801, using the second charged particle beam 312. Interaction radiation,
for example X-rays or cathodoluminescence light, is detected using the radiation detector
500. In particular, X-rays may be detected and may be used for carrying out EDX or
WDX. EDX and WDX may be used to identify the first material characteristics such as
the elements and the composition of elements of the first lamella 807 at each pixel.
Additionally or alternatively, interaction particles, for example backscattered electrons,
are detected using the EBSD detector 336, which is arranged, for example, in the position
Pos A (see
Figures 1 and 3). EBSD is used to analyze the crystallographic orientation of the material of the first
lamella 807. The EBSD detector 336 generates EBSD detection signals. The control unit
700 generates an electron backscatter diffraction pattern (EBSP) of the first lamella
807 based on the EBSD detection signals. The EBSP of the first lamella 807 comprises
information about Kikuchi bands corresponding to lattice diffraction planes of the
first lamella 807. Additionally or alternatively, the first lamella 807 may also be
analyzed by using TKD. The second charged particle beam 312 is guided to the second
surface 801. The first lamella 807 is thin enough to be transparent to electrons of
the second charged particle beam 312. In other words, the electrons of the second
charged particle beam 312 may transmit through the first lamella 807. The scattered
and transmitted electrons of the second charged particle beam 312 emerging from a
bottom side of the first lamella 807 are detected using the EBSD detector 336, which
is arranged in the position Pos B (see
Figures 1
and 3). The object holder 328 is designed in such a way that the scattered and transmitted
electrons may be detected by the EBSD detector 336. The EBSD detector 336 generates
detector signals used for acquiring and recording diffraction patterns of the first
lamella 807, the diffraction patterns being projected from the bottom side of the
first lamella 807 to the EBSD detector 336.
[0068] The above mentioned also applies to the second lamella 808. In other words, the second
lamella 808 is analyzed by identifying second material characteristics of each pixel
of the third image pixels of the third image, namely the image of the first side 805,
using the second charged particle beam 312. X-rays may be used for carrying out EDX
or WDX. EDX and WDX may be used to identify the second material characteristics such
as the elements and the composition of elements of the second lamella 808 at each
pixel. Additionally or alternatively, interaction particles, for example backscattered
electrons, are detected using the EBSD detector 336, which is arranged, for example,
in the position Pos A (see
Figures 1 and 3). Again, EBSD is used to analyze the crystallographic orientation of the material of
the second lamella 808. Additionally or alternatively, the second lamella 808 may
also be analyzed by using TKD. The second charged particle beam 312 is guided to the
first side 805 of the second lamella 808. The second lamella 808 is thin enough to
be transparent to electrons of the second charged particle beam 312. In other words,
the electrons of the second charged particle beam 312 may transmit through the second
lamella 808. The scattered and transmitted electrons of the second charged particle
beam 312 emerging from a bottom side of the second lamella 808 are detected using
the EBSD detector 336, which is arranged in the position Pos B (see
Figures 1 and 3).
[0069] The above mentioned may also apply to the third lamella 809. In other words, the
third lamella 809 is analyzed by identifying third material characteristics of each
pixel of the fourth image pixels of the fourth image, namely the image of the second
side 806, using the second charged particle beam 312. X-rays may be used for carrying
out EDX or WDX. EDX and WDX may be used to identify the third material characteristics
such as the elements and the composition of elements of the third lamella 809 at each
pixel. Additionally or alternatively, interaction particles, for example backscattered
electrons, are detected using the EBSD detector 336, which is arranged, for example,
in the position Pos A (see
Figures 1 and 3). EBSD is used to analyze the crystallographic orientation of the material of the third
lamella 809. Additionally or alternatively, the third lamella 809 may also be analyzed
by using TKD. The second charged particle beam 312 is guided to the second side 806
of the third lamella 809. The third lamella 809 is thin enough to be transparent to
electrons of the second charged particle beam 312. In other words, the electrons of
the second charged particle beam 312 may transmit through the third lamella 809. The
scattered and transmitted electrons of the second charged particle beam 312 emerging
from a bottom side of the third lamella 809 are detected using the EBSD detector 336,
which is arranged in the position Pos B (see
Figures 1 and 3).
[0070] The embodiments of the above mentioned methods now provide for generating filtered
data for each pixel or a group of pixels of the generated images of the first lamella
807, the second lamella 808 and the third lamella 809. More precisely, filtered data
is generated for each pixel of the second image of the second surface 801 of the first
lamella 807, of the third image of the first side 805 of the second lamella 808 and
of the fourth image of the third side 806 of the third lamella 809. In other words,
first filtered data of each pixel of the second image pixels is generated using at
least one first image filter for processing the second image data for each pixel of
the second image pixels. Moreover, second filtered data of each pixel of the third
image pixels is generated using at least one second image filter for processing the
third image data for each pixel of the third image pixels. Furthermore, third filtered
data for each pixel of the fourth image pixels is generated using at least one third
image filter for processing the fourth image data for each pixel of the fourth image
pixels. In other words, each pixel of the second image pixels, of the third image
pixels and/or of the fourth image pixels is filtered using at least one image filter.
The first image filter, the second image filter and the third image filter may each
be a digital image filter. In particular, at least one of the aforementioned filters
may be one of the following filters: a Gabor filter, a mean filter, a variance filter,
a histogram oriented gradient filter, a maximum filter, a minimum filter and a Kuwahara
filter. The first image filter, the second image filter and the third image filter
may not be identical. However, in one embodiment of the invention, at least two of
the filters, namely the first image filter, the second image filter and the third
image filter, are identical. For example, all image filters can be identical. Moreover,
in a further embodiment of the invention, more than one image filter is used for generating
filtered data for a particular pixel, thus generating more than one image based on
filtered data using different image filters.
[0071] The aforementioned is further explained with respect to the second image of the second
surface 801 only. As mentioned above, the second surface 801 is part of the first
lamella 807.
Figure 9A schematically shows the image of the second surface 801. As mentioned above, this
image was generated using the second charged particle beam 312 and detecting interaction
particles such as secondary electrons and/or backscattered electrons using the detector
317. A first image filter in the form of a convolution filter is now used to generate
a first filtered image of the second image. The convolution filter is used to filter
each pixel of the second image of the second surface 801 shown in
Figure 9A. The generated first filtered image is shown in
Figure 9B. Additionally, a second image filter in the form of a maximum filter is now used to
generate a second filtered image of the second image. The maximum filter is used to
filter each pixel of the second image of the second surface 801 shown in
Figure 9A. The generated second filtered image is shown in
Figure 9C. Moreover, a third image filter in the form of a minimum filter is now used to generate
a third filtered image of the second image, wherein the minimum filter is used to
filter each pixel of the second image of the second surface 801 shown in
Figure 9A. The generated third filtered image is shown in
Figure 9D. A fourth image filter in the form of a Kuwahara filter is now used to generate a
fourth filtered image of the second image, wherein the Kuwahara filter is used to
filter each pixel of the second image of the second surface 801 shown in
Figure 9A. The generated fourth filtered image is shown in
Figure 9E. A fifth image filter in the form of a first Gabor filter having first parameters
is now used to generate a fifth filtered image of the second image, wherein the first
Gabor filter is used to filter each pixel of the second image of the second surface
801 shown in
Figure 9A. The generated fifth filtered image is shown in
Figure 9F. A sixth image filter in the form of a second Gabor filter having second parameters
is now used to generate a sixth filtered image of the second image, wherein the second
Gabor filter is used to filter each pixel of the second image of the second surface
801 shown in
Figure 9A. The generated sixth filtered image is shown in
Figure 9G. A seventh image filter in the form of a third Gabor filter having third parameters
is now used to generate a seventh filtered image of the second image, wherein the
third Gabor filter is used to filter each pixel of the second image of the second
surface 801 shown in
Figure 9A. The generated seventh filtered image is shown in
Figure 9H.
[0072] After having carried out method step S10, several filtered images have been generated
associated to the second image, to the third image and to the fourth image. Therefore,
it is possible to generate a vector for each of the second image, the third image
and the fourth image for each pixel of each filtered image, the vector comprising
the filtered data for each filtered image for a particular pixel. This is schematically
shown in
Figure 9I. Figure 9I schematically shows the several generated filtered images, namely the first filtered
image to the seventh filtered image. A vector may be guided through each pixel of
the first filtered image to the seventh filtered image. The vector comprises for each
pixel filtered data of each filtered image. In other words, the vector is a feature
vector. It may have the form

wherein

is the vector for a specific pixel;
D1 is the filtered data at this specific pixel in the first filtered image;
D2 is the filtered data at this specific pixel in the second filtered image;
D3 is the filtered data at this specific pixel in the third filtered image;
D4 is the filtered data at this specific pixel in the fourth filtered image;
D5 is the filtered data at this specific pixel in the fifth filtered image;
D6 is the filtered data at this specific pixel in the sixth filtered image;
D7 is the filtered data at this specific pixel in the seventh filtered image;
[0073] The information with respect to the identified material characteristics and the filtered
data of the filtered images is now used to obtain information on the material characteristics
for each pixel of each surface generated when material is sequentially removed from
the object 304 (method steps S11 and S12). In particular, one of the following methods
may be used: a random decision forest, association rule learning, an artificial neural
network, a support vector machine and a Bayesian network. The aforementioned methods
are machine learning methods for classification, wherein classification is the problem
of identifying to which of a set of categories a new set of data belongs. The embodiment
of
Figure 4 and the example of
Figure 5 may use a random decision forest which is explained using
Figures 10 to 13. The process of using the random decision forest comprises three steps, namely a first
step, a second step and a third step. The random decision forest is trained (first
step) and the training is validated (second step). After validation, the random decision
forest may be used to classify and assign material characteristics to each pixel of
each surface generated and imaged (third step).
[0074] The first step is now discussed. For easier illustration, we assume that the image
of the second surface 801 as shown in
Figure 9A is actually an image as shown in
Figure 10. The image shown in
Figure 10 is called training image hereinafter. The training image may comprise 256 × 256 pixels,
which would mean a total of 65536 pixels. The invention is not restricted to such
number of pixels. Rather, each image of each surface generated when material is sequentially
removed from the object 304 may comprise any number of pixels suitable for carrying
out the invention.
[0075] Each pixel of the training image has a specific material characteristic (hereinafter
referred to as a "class"). The training image comprises pixels belonging to three
different classes, namely classes A, B and C.
[0076] The training image is used for carrying out method step S10. As mentioned above,
after having carried out method step S10, several filtered images have been generated
associated to the training image. A vector may be generated for the training image
as shown in
Figure 9I. It is now possible for each filtered image, namely the first filtered image, the
second filtered image, the third filtered image, the fourth filtered image, the fifth
filtered image, the sixth filtered image and the seventh filtered image, to determine
a gray value at each pixel from each filtered image, for example by reading out the
pixel values from each filtered image or by using an image recognition algorithm known
in the art, for example a thresholding process. The gray values obtained at each pixel
of the first to seventh filtered images are stored in the database 702 and are arranged
in a table together with the gray values at each pixel of the training image. The
table may have the following form:
Table 1:
| Pixel # |
GV0 |
GV1 |
GV2 |
GV3 |
GV4 |
GV5 |
GV6 |
GV7 |
Class |
| 1 |
204 |
205 |
181 |
226 |
129 |
-0.06 |
207 |
205 |
A |
| 2 |
200 |
203 |
179 |
222 |
125 |
-0.05 |
203 |
202 |
A |
| 3 |
198 |
196 |
177 |
220 |
122 |
-0.04 |
195 |
196 |
A |
| ··· |
··· |
··· |
··· |
··· |
··· |
··· |
··· |
··· |
··· |
| 32768 |
172 |
170 |
155 |
194 |
253 |
0.2 |
166 |
160 |
B |
| 32769 |
171 |
169 |
154 |
193 |
252 |
0.19 |
164 |
159 |
B |
| ··· |
··· |
··· |
··· |
··· |
··· |
··· |
··· |
··· |
··· |
| 65535 |
147 |
147 |
87 |
203 |
253 |
0.01 |
144 |
145 |
C |
wherein
- Pixel #
- is the number of the pixel in the training image;
- GV0
- is the gray value of a specific pixel in the training image;
- GV1
- is the gray value of a specific pixel in the first filtered image;
- GV2
- is the gray value of a specific pixel in the second filtered image;
- GV3
- is the gray value of a specific pixel in the third filtered image;
- GV4
- is the gray value of a specific pixel in the fourth filtered image;
- GV5
- is the gray value of a specific pixel in the fifth filtered image;
- GV6
- is the gray value of a specific pixel in the sixth filtered image;
- GV7
- is the gray value of a specific pixel in the seventh filtered image; and wherein
- class
- is the class (i.e. the material characteristic) the pixel belongs to.
[0077] The random decision forest is now trained as shown in
Figure 11A. During the training process, the random forest algorithm builds a model. This model
is based on decision trees which comprise nodes with specific rules for splitting.
Each node of a decision tree represents a feature which is a gray value of a specific
pixel in a specific filtered image. The nodes of a decision tree may branch into two
branches of the decision tree. If the value of the pixel for that feature is less
than or equal to a specific value, then the pixel travels down a specific branch of
the decision tree, for example the left branch. If the value of the pixel of that
feature is more than the specific value, it travels down the other branch of the decision
tree, for example the right branch. This will be explained in detail below.
[0078] The random decision forest method comprises several decision trees, namely decision
trees 1 to N, wherein N is an integer. N might be any integer which is sufficient
for carrying out the invention. For example, N can be in the range of 100 to 300,
or in the range of 100 to 200. In an exemplary embodiment of the invention, N is 100.
Therefore, this exemplary embodiment comprises 100 decision trees. The training of
the random decision forest is carried out using the data comprised in table 1. More
precisely, each decision tree of the decision trees 1 to N is generated using the
data of pixels from table 1 which are randomly selected. Therefore, those pixels are
also called random sample of pixels or boot strap sample hereinafter. Typically, 63.2%
of all available pixels and their corresponding data shown in table 1 are used as
the random sample of pixels (random sample of features). Each decision tree 1 to N
has its own random sample of pixels. Therefore, the random sample of pixels is randomly
selected for each decision tree 1 to N.
[0079] The generation of decision tree 1 is now explained in detail. Decision trees 2 to
N are generated in the same manner. Decision tree 1 comprises nodes whose number is
randomly selected. For each node of decision tree 1, two features are randomly selected
out of the random sample of features, for example GV1 as feature 1 and GV6 as feature
2. It is then decided whether feature 1 or feature 2 would be used for the node based
on the best split criteria. The best split criteria also determines the split values
for the node.
[0080] The best split is based on the so-called Gini impurity criterion. The Gini impurity
criterion is a measure of how often a randomly chosen element from a set would be
incorrectly labeled if it was randomly labeled according to the distribution of labels
in a subset. The Gini impurity index at each node t in a decision tree is defined
as:

wherein
- G
- is the Gini impurity index,
- pi
- is the ratio of a specific class at the node t, and wherein
- n
- is the total number of classes.
[0081] After splitting a node t into a first child node t
1 and a second child node t
2, the Gini index of split data is defined as:

wherein
- N(t)
- is the total number of available or selected pixels,
- N(t1)
- is the number of pixels belonging to specific classes at a node t1, and
- N(t2)
- is the number of pixels belonging to specific classes at a node t2.
[0082] The feature providing the smallest Gini
split(t) is chosen for the node. This is explained in detail further below using a specific
embodiment. We assume that GV2 as feature 1 and GV6 as feature 2 are randomly selected
out of the random sample of features for a node t. It is then decided whether feature
1 or feature 2 is used for the node t based on the best split criteria. For simpler
presentation purposes we further assume that only 6 pixels of GV2 and GV6 are available,
namely
Table 2:
| Pixel # |
GV2 |
GV6 |
Class |
| 1 |
181 |
207 |
A |
| 2 |
179 |
203 |
A |
| 3 |
177 |
195 |
A |
| 32768 |
155 |
166 |
B |
| 32769 |
154 |
164 |
B |
| 65535 |
87 |
144 |
C |
[0083] The total number of selected pixels is 6, therefore N(t) = 6. Gini
split(t) is now calculated for the feature 1, namely GV2:
Table 3:
| Subnode |
Split criteria |
Class A |
Class B |
Class C |
Pixels Ni(t) |
G(t) |
Ginisplit |
| t1 |
GV2<=87 |
0 |
0 |
1 |
1 |
0 |
0.4 |
| t2 |
GV2>87 |
3 |
2 |
0 |
5 |
0.48 |
|
| t1 |
GV2<=154 |
0 |
1 |
1 |
2 |
0.5 |
0.4166667 |
| t2 |
GV2>154 |
3 |
1 |
0 |
4 |
0.375 |
|
| t1 |
GV2<=155 |
0 |
2 |
1 |
3 |
0.444444 |
0.2222222 |
| t2 |
GV2>155 |
3 |
0 |
0 |
3 |
0 |
|
| t1 |
GV2<=177 |
1 |
2 |
1 |
4 |
0.625 |
0.4166667 |
| t2 |
GV2>177 |
2 |
0 |
0 |
2 |
0 |
|
| t1 |
GV2<=179 |
2 |
2 |
1 |
5 |
0.64 |
0.53333333 |
| t2 |
GV2>179 |
1 |
0 |
0 |
1 |
0 |
|
[0084] The smallest Gini
split (t) is for GV2 <= 155. Gini
split (t) is now calculated for the feature 2, namely GV6, in an identical manner. We assume
that Gini
split (t) for GV6 is higher than Gini
split (t) for GV2. Therefore, GV2 is selected as the feature for the node t. The specific
value is 155. If a pixel having a certain gray value to be evaluated runs down the
decision tree and if the gray value of that pixel is less than or equal to 155, the
pixel runs down the left branch of the node t to the node t
1. If a pixel having a certain gray value to be evaluated runs down the decision tree
and if the gray value of that pixel is higher than 155, the pixel runs down the right
branch of node t to the node t
2.
[0085] The aforementioned is carried out for each node of each decision tree 1 to N. An
embodiment of a decision tree is shown in
Figure 11B. The end nodes (hereinafter called terminal nodes) are assigned to that class of the
pixel used for training which is ending up at a specific terminal node and which was
already labeled and assigned to a specific class. For example, the terminal node at
the far left comprises a pixel which has a grey value <= 144. Therefore, this terminal
node is assigned to class C since the gray value of pixel 65535 (which is 144) of
GV6 belongs to class C.
[0086] As mentioned above, decision trees 2 to N are generated in analogy to the generation
of decision tree 1.
[0087] As mentioned above, in the second step, the training of the random decision forest
is validated. The validation is shown in
Figure 12. The validation of decision tree 1 is now explained in detail. Decision trees 2 to
N are validated in the same manner.
[0088] For validation of decision tree 1, the remaining 36.8 % pixels and their corresponding
data of table 1 which have not been used for training are now used for validation.
Those pixels and their corresponding data now used for validation are also called
out-of-bag data. Since the pixels used for training each decision tree 1 to N are
randomly selected in each case, the out-of-bag data for each decision tree 1 to N
differ from each other. Each pixel of the out-of-bag data of decision tree 1 is pushed
down decision tree 1. The pixel is guided down decision tree 1. It is decided at each
node of decision tree 1 whether the pixel has to be pushed down the left branch or
the right branch depending on the gray value of the pixel. If the gray value of the
pixel is lower than or equal to the specific value as above mentioned then the pixel
travels down the left branch. If the gray value of the pixel is higher than the specific
value as above mentioned then the pixel travels down the right branch. Each pixel
of the out-of-bag data being pushed down decision tree 1 ends up at a terminal node.
As mentioned above, the terminal node is assigned to a specific class, namely class
A, B or C, in the embodiment described here. Therefore, when the pixel of the out-of-bag
data being pushed down decision tree 1 ends up at a terminal node, decision tree 1
has voted that this specific pixel has the same class as the class being assigned
to this terminal node. This means that the decision tree 1 has voted that the class
of this specific pixel is the same as the one assigned to this terminal node.
[0089] Step 2, namely the validation of the random decision forest, also comprises calculating
the misclassification rate (the so called out-of-bag error rate) by comparing the
class of each pixel as mentioned in table 1 to the class assigned by each decision
tree 1 to N. The out-of-bag error rate of all decision trees 1 to N of the random
decision forest is aggregated to determine an overall out-of-bag error rate. If the
overall out-of-bag error rate is too high (for example, higher than 0.4), the training
is repeated with more data included in the random sample of pixels than before.
[0090] The generated random decision forest is now used to classify each pixel of each image
of each surface generated when material is sequentially removed from the object 304,
wherein the pixels of these images have not yet been analyzed with respect to the
material characteristics. This is step 3 as mentioned above. Each pixel from these
images is pushed down each decision tree 1 to N. The pixel is guided down each decision
tree. It is decided at each node of each decision tree whether the pixel has to be
pushed down the left branch or the right branch depending on the gray value of the
pixel as mentioned above. Each pixel being pushed down each decision tree 1 to N ends
up at a terminal node. As mentioned above, the terminal nodes are assigned to a specific
class, namely class A, B or C in the embodiment described here. Therefore, when each
pixel ends up at a terminal node of decision trees 1 to N, decision trees 1 to N have
voted that this specific pixel has the same class as the class being assigned to this
terminal node. This means that decision trees 1 to N have voted that the class of
a specific pixel is the same as the one assigned to a terminal node. Now, the probability
P
class for each pixel to be part of a specific class is calculated as the ratio of total
votes for the class to the total numbers of decision trees:

[0091] If the total number of decision trees is, for example, 100 (i.e. N = 100), and 95
of the decision trees vote that a specific pixel is part of class A, then the probability
of the pixel to be classified in class A would be 0.95.
[0092] After carrying out step 3, it is possible to generate probability maps for each class.
Moreover, a segmented image for each image of each generated surface is then generated
by assigning the class at each pixel based on the highest probability. The segmented
image comprises information on the material characteristics of the object 304 at each
pixel. The segmented images may then be used to generate a 3D analytical data set
of the object 304 which is already known in the art, for example in
WO 2010/108852 A1.
[0093] The workflows depicted
in Figures 4 ,5 and 8 can be summarized as follows: When conducting the steps S1 to S5 (
Figure 4) or steps S1A to S5 (
Figure 5), a first data set of a three dimensional measurement volume of the object with a
high resolution using the charged particle beam is obtained. This first data set is
based on detected interaction particles leaving the object due to an impingement of
the charged particle beam. The first data set comprises a plurality of individual
voxels.
[0094] In step S7, at least one lamella is extracted from the object from a region neighbored
to the three dimension measurement volume by using the charged particle beam device.
[0095] In step S8, a second data set of the at least one lamella with a high resolution
is obtained using said charged particle beam. This second data set is also based on
detected interaction particles leaving the object due to an impingement of the charged
particle beam.
[0096] In step S9, charged particle beam analytics using the charged particle beam device
is performed at the at least one lamella to identify material characteristics of the
at least one lamella. The charged particle beam analytics can be at least one of:
EDX, WDX, EBSD and TKD. The resolution of the charged particle beam analytics achieved
in this step is considerable lower than the high resolution imaging data of the first
and second data set. However, since the charged particle beam analytics are performed
at the at least one lamella having a thickness of 10 - 100 nm, the resolution of the
charged particle beam analytics achieved in this step is still in the range some ten
nm, i.e. 10 to 30 nm, and, accordingly, is much higher than the resolution which could
be achieved if the charged particle beam analytics were performed on a larger object
directly.
[0097] In step S10, data of said second data set, high-resolution material contrast image
data of the at least one lamella, are allocated to said material characteristics of
the lamella identified in step 9.
[0098] In step S12, material characteristics are allocated to said individual voxels representing
the three dimensional measurement volume of the object based on said allocation of
said second data set to said material characteristics performed in step S10. In the
above described way, the resolution of the charged particle beam analytics achieved
in step S9 is transferred in step 12 to the complete three dimensional measurement
volume of the object from which the data in the first data set are collected.
[0099] In an embodiment in step S7, two additional lamellas are extracted from the object,
whereby said additional lamellas are extracted at different sides relative to said
three dimensional measurement volume. In this embodiment in step S9, charged particle
analytics are also performed at these two additional lamellas so that altogether charged
particle analytics are performed at three lamellas extracted at three different sides
relative to said three dimensional measurement volume.
[0100] In a further embodiment, the workflow can include a further step S10 in which first
feature vectors are generated based on said second data set by performing data filtering.
In such embodiment, the allocation of data of said second data set to material characteristics
can be performed by allocating particular feature vectors to particular material characteristics.
In such embodiment, in addition, in an additional intermediate step S11, second feature
vectors can be generated based on said first data set by performing data filtering.
The allocation of material characteristics to the individual voxels of the first data
set can be carried out by comparing said first feature vectors with said second feature
vectors and identifying regions in the first data set which have similar feature vectors
as regions in the lamella(s). Regions within the three dimensional measurement volume
having feature vectors which are similar to a particular feature vector in the lamella(s)
are supposed to have a similar material characteristic as the respective location
in the lamella. The embodiments of the invention have the advantages mentioned above.
Various embodiments discussed herein may be combined with each other in appropriate
combinations in connection with the system described herein. Additionally, in some
instances, the order of steps in the flow diagrams, flowcharts and/or described flow
processing may be modified, where appropriate. Further, various aspects of the system
described herein are implemented using software, hardware, a combination of software
and hardware and/or other computer-implemented modules or devices having the described
features and performing the described functions. The system may further include a
display and/or other computer components for providing a suitable interface with a
user and/or with other computers.
[0101] Software implementations of aspects of the system described herein include executable
code that is stored in a computer-readable medium and executed by one or more processors.
The computer-readable medium may include volatile memory and/or non-volatile memory,
and may include, for example, a computer hard drive, ROM, RAM, flash memory, portable
computer storage media such as a CD-ROM, a DVD-ROM, an SO card, a flash drive or other
drive with, for example, a universal serial bus (USB) interface, and/or any other
appropriate tangible or non-transitory computer-readable medium or computer memory
on which executable code may be stored and executed by a processor. The system described
herein may be used in connection with any appropriate operating system.
[0102] Other embodiments of the invention will be apparent to those skilled in the art from
a consideration of the specification and/or an attempt to put into practice the invention
disclosed herein. It is intended that the specification and examples be considered
as exemplary only, with the true scope of the invention being indicated by the following
claims.
List of reference signs
[0103]
- 300
- charged particle beam device
- 301
- first particle beam column
- 302
- second particle beam column
- 303
- object chamber
- 304
- object
- 305
- first optical axis
- 306
- second optical axis
- 307
- second beam generator
- 308
- first electrode
- 309
- second electrode
- 310
- third electrode
- 311
- beam guide tube
- 312
- second charged particle beam
- 313
- collimator arrangement
- 314
- first annular coil
- 315
- yoke
- 316
- pin hole diaphragm
- 317
- detector
- 318
- central opening
- 319
- second objective lens
- 320
- magnetic lens
- 321
- electrostatic lens
- 322
- second annular coil
- 323
- inner pole piece
- 324
- outer pole piece
- 325
- end of beam guiding tube
- 326
- terminating electrode
- 327
- raster device
- 328
- object holder
- 329
- first charged particle beam
- 330
- first beam generator
- 331
- extraction electrode
- 332
- collimator
- 333
- variable aperture
- 334
- first objective lens
- 335
- raster electrodes
- 336
- EBSD detector
- 337
- gas injection unit
- 500
- radiation detector
- 600
- pressure sensor
- 601
- pump system
- 700
- control unit
- 701
- processor
- 702
- database
- 703
- particle detector
- 800
- first surface
- 801
- second surface
- 803
- opening
- 804
- boundary side
- 805
- first side
- 806
- second side
- 807
- first lamella
- 808
- second lamella
- 809
- third lamella
- Pos A
- first position
- Pos B
- second position
- S1 to S12
- method steps
- T1 to T3
- thicknesses
1. Method for analyzing an object (304) using a charged particle beam device (300),
- the charged particle beam device (300) comprising a first charged particle beam
generator (330) for generating a first charged particle beam (329) having first charged
particles, a first objective lens (334) for focusing the first charged particle beam
(329) onto the object (304), a second charged particle beam generator (307) for generating
a second charged particle beam (312) having second charged particles, a second objective
lens (319) for focusing the second charged particle beam (312) onto the object (304),
a first detection unit (317, 703) and a second detection unit (336, 500),
wherein the method comprises the following steps:
- guiding the first charged particle beam (329) over the object (304), removing material
from the object (304) using the first charged particle beam (329), exposing a first
surface (800) of the object (304) when removing the material from the object (304),
guiding the second charged particle beam (312) over the first surface (800) of the
object (304), detecting first interaction particles using the first detection unit
(317, 703), the first interaction particles arising when the second charged particle
beam (312) impinges on the first surface (800), generating a first detection signal
using the first detection unit (317, 703) and generating a first image of the first
surface (800) of the object (304) using the first detection signal, the first image
comprising first image pixels, each pixel of the first image pixels comprising first
image data;
- guiding the first charged particle beam (329) over the object (304), removing material
comprising the first surface (800) from the object (304) using the first charged particle
beam (329), exposing a second surface (801) of the object (304) when removing the
material from the object (304), guiding the second charged particle beam (312) over
the second surface (801) of the object (304), detecting second interaction particles
using the first detection unit (317, 703), the second interaction particles arising
when the second charged particle beam (312) impinges on the second surface (800),
generating a second detection signal using the first detection unit (317, 703) and
generating a second image of the second surface (801) of the object (304) using the
second detection signal, the second image comprising second image pixels, each pixel
of the second image pixels comprising second image data, wherein an opening (803)
is generated when removing the material from the object (304) so as to expose the
first surface (800) and the second surface (801) of the object (304), wherein the
opening (803) comprises a first side (804) comprising the second surface (801) and
a second side (805, 806) extending from the second surface (804) of the object (304)
in a direction away from the second surface (801);
- generating a first lamella (807) comprising the first side (804) of the opening
(800) having the second surface (801) as an outer surface, and generating a second
lamella (807, 809) comprising the second side (805, 806) of the opening (800);
- guiding the second charged particle beam (312) over the second side (805, 806) of
the object (304), detecting third interaction particles using the first detection
unit (317, 703), the third interaction particles arising when the second charged particle
beam (312) impinges on the second side (805, 806) of the object (304), generating
a third detection signal using the first detection unit (317, 703) and generating
a third image of the second side (805, 806) of the object (304) using the third detection
signal, the third image comprising third image pixels, each pixel of the third image
pixels comprising third image data;
- analyzing the first lamella (807) by identifying first material characteristics
of the first lamella (807) associated to each pixel of the second image pixels using
at least one of: the first charged particle beam (329) and the second charged particle
beam (312), and detecting at least one of: fourth interaction particles and first
interaction radiation using the second detection unit (336, 500);
- analyzing the second lamella (808) by identifying second material characteristics
of the second lamella associated to each pixel of the third image pixels using at
least one of: the first charged particle beam (329) and the second charged particle
beam (312) and detecting at least one of: fifth interaction particles and second interaction
radiation using the second detection unit (336, 500);
- generating first filtered data for each pixel of the second image pixels using at
least one first image filter for processing the second image data for each pixel of
the second image pixels, and generating second filtered data for each pixel of the
third image pixels using at least one second image filter for processing the third
image data for each pixel of the third image pixels;
- identifying data identical or similar to the first image data for each pixel of
the first image pixels of the first image from among the following: the second image
data of each pixel of the second image pixels, the third image data of each pixel
of the third image pixels, the first filtered data for each pixel of the second image
pixels and the second filtered data for each pixel of the third image pixels; and
- assigning material characteristics to at least one pixel of the first image pixels
of the first image, wherein
(i) the first material characteristics are assigned if at least one of: the identified
second image data of a pixel of the second image pixels and the identified first filtered
data for a pixel of the second image pixels is identical or similar to the first image
data of the at least one pixel of the first image pixels; and wherein
(ii) the second material characteristics are assigned if at least one of:
the identified third image data of a pixel of the third image pixels and the identified
second filtered data for a pixel of the third image pixels is identical or similar
to the first image data of the at least one pixel of the first image pixels.
2. The method according to claim 1, the method further comprising:
- generating a third lamella (809) comprising a third side (806) of the opening (803),
the third side (806) and the second side (805) being arranged opposite to each other
and the first side (804) being arranged between the second side (805) and the third
side (806);
- guiding the second charged particle beam (312) over the third side (806) of the
object (304), detecting sixth interaction particles using the first detection unit
(317, 703), the sixth interaction particles arising when the second charged particle
beam (312) impinges on the third side (806) of the object (304), generating a fourth
detection signal using the first detection unit (317, 703) and generating a fourth
image of the third side (806) of the object (304) using the fourth detection signal,
the fourth image comprising fourth image pixels, each pixel of the fourth image pixels
comprising fourth image data;
- analyzing the third lamella (809) by identifying third material characteristics
of the third lamella (809) associated to each pixel of the fourth image pixels using
at least one of: the first charged particle beam (329) and the second charged particle
beam (312), and detecting at least one of: seventh interaction particles and third
interaction radiation using the second detection unit (336, 500);
- generating third filtered data for each pixel of the fourth image pixels using at
least one third image filter for processing the fourth image data for each pixel of
the fourth image pixels;
- the step of identifying data identical or similar to the first image data for each
pixel of the first image pixels of the first image also comprising identifying from
among the following: the fourth image data of each pixel of the fourth image pixels
and the third filtered data for each pixel of the fourth image pixels;
- the step of assigning material characteristics to at least one pixel of the first
image pixels of the first image comprising assigning the third material characteristics
if at least one of: the identified fourth image data of a pixel of the fourth image
pixels and the identified third filtered data for a pixel of the fourth image pixels
is identical or similar to the first image data of the at least one pixel of the first
image pixels.
3. The method according to claim 1, wherein the step of identifying identical or similar
data comprises comparing the first image data for each pixel of the first image pixels
of the first image to at least one of: the second image data of each pixel of the
second image pixels, the third image data of each pixel of the third image pixels,
the first filtered data for each pixel of the second image pixels and the second filtered
data for each pixel of the third image pixels.
4. The method according to claim 1, further comprising at least one of:
(i) analyzing the first lamella (807) using at least one of: X-rays and cathodoluminescence
light;
(ii) analyzing the second lamella (808) using at least one of: X-rays and cathodoluminescence
light.
5. The method according to claim 1, further comprising at least one of:
(i) analyzing the first lamella (807) using at least one of: EDX, WDX, EBSD and TKD;
(ii) analyzing the second lamella (808) using at least one of: EDX, WDX, EBSD and
TKD.
6. The method according to claim 1, wherein the step of identifying identical or similar
data comprises using a learning method for classification.
7. The method according to claim 6, wherein the step of identifying identical or similar
data comprises using at least one of: a random decision forest, association rule learning,
an artificial neural network, a support vector machine and a Bayesian network.
8. The method according to claim 1, further comprising: using at least one of the following
filters as the image filter: a Gabor filter, a mean filter, a variance filter, a histogram
oriented gradient filter, a maximum filter, a minimum filter and a Kuwahara filter.
9. Computer program product comprising a program code which is adapted to be loaded into
a processor (701) and, which, when being executed, controls a charged particle beam
device (300) in such a way that a method according to claim 1 is carried out.
10. Charged particle beam device (300) for analyzing an object (304), comprising
- a first charged particle beam generator (330) for generating a first charged particle
beam (329) having first charged particles,
- a first objective lens (334) for focusing the first charged particle beam (329)
onto the object (304),
- a second charged particle beam generator (302) for generating a second charged particle
beam (312) having second charged particles,
- a second objective lens (319) for focusing the second charged particle beam (312)
onto the object (304),
- a first detection unit (317, 703) for detecting interaction particles and a second
detection unit (336, 500) for detecting at least one of: interaction particles and
interaction radiation, the interaction particles and the interaction radiation arising
when at least one of: (i) the first charged particle beam (329) and (ii) the second
charged particle beam (312) impinges on the object (304), and
- a processor (701) into which a computer program product according to claim 9 is
loaded.
11. The charged particle beam (300) device according to claim 10, further comprising one
of the following features:
- a first detector comprises the first detector unit (317, 703) and a second detector
comprises the second detector unit (336, 500); and
- a single detector comprises the first detector unit (317, 703) and the second detector
unit (336, 500).
12. The charged particle beam device (300) according to claim 10, wherein the charged
particle beam device (300) is at least one of the following: an electron beam device
and an ion beam device.
1. Verfahren zum Analysieren eines Objekts (304) unter Verwendung einer Ladungsträgerstrahlvorrichtung
(300), wobei
- die Ladungsträgerstrahlvorrichtung (300) einen ersten Ladungsträgerstrahlgenerator
(330) zum Erzeugen eines ersten Ladungsträgerstrahls (329), der erste Ladungsträger
aufweist, eine erste Objektivlinse (334) zum Fokussieren des ersten Ladungsträgerstrahls
(329) auf das Objekt (304), einen zweiten Ladungsträgerstrahlgenerator (307) zum Erzeugen
eines zweiten Ladungsträgerstrahls (312), der zweite Ladungsträger aufweist, eine
zweite Objektivlinse (319) zum Fokussieren des zweiten Ladungsträgerstrahls (312)
auf das Objekt (304), eine erste Detektionseinheit (317, 703) und eine zweite Detektionseinheit
(336, 500) umfasst und
das Verfahren die folgenden Schritte umfasst:
- Führen des ersten Ladungsträgerstrahls (329) über das Objekt (304), Entfernen von
Material vom Objekt (304) unter Verwendung des ersten Ladungsträgerstrahls (329),
Freilegen einer ersten Oberfläche (800) des Objekts (304), wenn das Material vom Objekt
(304) entfernt wird, Führen des zweiten Ladungsträgerstrahls (312) über die erste
Oberfläche (800) des Objekts (304), Detektieren erster Interaktionspartikel unter
Verwendung der ersten Detektionseinheit (317, 703), wobei die ersten Interaktionspartikel
entstehen, wenn der zweite Ladungsträgerstrahl (312) auf die erste Oberfläche (800)
einwirkt, Erzeugen eines ersten Detektionssignals unter Verwendung der ersten Detektionseinheit
(317, 703) und Erzeugen eines ersten Bildes der ersten Oberfläche (800) des Objekts
(304) unter Verwendung des ersten Detektionssignals, wobei das erste Bild erste Bildpixel
umfasst und jedes Pixel der ersten Bildpixel erste Bilddaten umfasst;
- Führen des ersten Ladungsträgerstrahls (329) über das Objekt (304), Entfernen von
Material, das die erste Oberfläche (800) umfasst, vom Objekt (304) unter Verwendung
des ersten Ladungsträgerstrahls (329), Freilegen einer zweiten Oberfläche (801) des
Objekts (304), wenn das Material vom Objekt (304) entfernt wird, Führen des zweiten
Ladungsträgerstrahls (312) über die zweite Oberfläche (801) des Objekts (304), Detektieren
zweiter Interaktionspartikel unter Verwendung der ersten Detektionseinheit (317, 703),
wobei die zweiten Interaktionspartikel entstehen, wenn der zweite Ladungsträgerstrahl
(312) auf die zweite Oberfläche (800) einwirkt, Erzeugen eines zweiten Detektionssignals
unter Verwendung der ersten Detektionseinheit (317, 703) und Erzeugen eines zweiten
Bildes der zweiten Oberfläche (801) des Objekts (304) unter Verwendung des zweiten
Detektionssignals, wobei das zweite Bild zweite Bildpixel umfasst, jedes Pixel der
zweiten Bildpixel zweite Bilddaten umfasst, eine Öffnung (803) erzeugt wird, wenn
das Material vom Objekt (304) entfernt wird, um die erste Oberfläche (800) und die
zweite Oberfläche (801) des Objekts (304) freizulegen, und die Öffnung (803) eine
erste Seite (804), die die zweite Oberfläche (801) umfasst, und eine zweite Seite
(805, 806), die sich von der zweiten Oberfläche (804) des Objekts (304) in einer Richtung
weg von der zweiten Oberfläche (801) erstreckt, umfasst;
- Erzeugen einer ersten Lamelle (807), die die erste Seite (804) der Öffnung (800),
die die zweite Oberfläche (801) als eine Außenoberfläche aufweist, umfasst, und Erzeugen
einer zweiten Lamelle (807, 809), die die zweite Seite (805, 806) der Öffnung (800)
umfasst;
- Führen des zweiten Ladungsträgerstrahls (312) über die zweite Seite (805, 806) des
Objekts (304), Detektieren dritter Interaktionspartikel unter Verwendung der ersten
Detektionseinheit (317, 703), wobei die dritten Interaktionspartikel entstehen, wenn
der zweite Ladungsträgerstrahl (312) auf die zweite Seite (805, 806) des Objekts (304)
einwirkt, Erzeugen eines dritten Detektionssignals unter Verwendung der ersten Detektionseinheit
(317, 703) und Erzeugen eines dritten Bildes der zweiten Seite (805, 806) des Objekts
(304) unter Verwendung des dritten Detektionssignals, wobei das dritte Bild dritte
Bildpixel umfasst und jedes Pixel der dritten Bildpixel dritte Bilddaten umfasst;
- Analysieren der ersten Lamelle (807) durch Identifizieren erster Materialeigenschaften
der ersten Lamelle (807), die jedem Pixel der zweiten Bildpixel zugeordnet sind, unter
Verwendung von Folgendem: des ersten Ladungsträgerstrahls (329) und/oder des zweiten
Ladungsträgerstrahls (312), und Detektieren von Folgendem: vierter Interaktionspartikel
und/oder einer ersten Interaktionsstrahlung unter Verwendung der zweiten Detektionseinheit
(336, 500);
- Analysieren der zweiten Lamelle (808) durch Identifizieren zweiter Materialeigenschaften
der zweiten Lamelle, die jedem Pixel der dritten Bildpixel zugeordnet sind, unter
Verwendung von Folgendem: des ersten Ladungsträgerstrahls (329) und/oder des zweiten
Ladungsträgerstrahls (312), und Detektieren von Folgendem: fünfter Interaktionspartikel
und/oder einer zweiten Interaktionsstrahlung unter Verwendung der zweiten Detektionseinheit
(336, 500);
- Erzeugen erster gefilterter Daten für jedes Pixel der zweiten Bildpixel unter Verwendung
mindestens eines ersten Bildfilters zum Verarbeiten der zweiten Bilddaten für jedes
Pixel der zweiten Bildpixel und Erzeugen zweiter gefilterter Daten für jedes Pixel
der dritten Bildpixel unter Verwendung mindestens eines zweiten Bildfilters zum Verarbeiten
der dritten Bilddaten für jedes Pixel der dritten Bildpixel;
- Identifizieren von Daten, die den ersten Bilddaten gleich oder ähnlich sind, für
jedes Pixel der ersten Bildpixel des ersten Bildes unter den Folgenden: den zweiten
Bilddaten jedes Pixels der zweiten Bildpixel, den dritten Bilddaten jedes Pixels der
dritten Bildpixel, den ersten gefilterten Daten für jedes Pixel der zweiten Bildpixel
und den zweiten gefilterten Daten für jedes Pixel der dritten Bildpixel; und
- Zuweisen von Materialeigenschaften zu mindestens einem Pixel der ersten Bildpixel
des ersten Bildes, wobei
(i)die ersten Materialeigenschaften zugewiesen werden, wenn: die identifizierten zweiten
Bilddaten eines Pixels der zweiten Bildpixel und/oder die identifizierten ersten gefilterten
Daten für ein Pixel der zweiten Bildpixel gleich oder ähnlich den ersten Bilddaten
des mindestens einen Pixels der ersten Bildpixel sind; und
(ii) die zweiten Materialeigenschaften zugewiesen werden, wenn: die identifizierten
dritten Bilddaten eines Pixels der dritten Bildpixel und/oder die identifizierten
zweiten gefilterten Daten für ein Pixel der dritten Bildpixel gleich oder ähnlich
den ersten Bilddaten des mindestens einen Pixels der ersten Bildpixel sind.
2. Verfahren nach Anspruch 1, wobei das Verfahren ferner Folgendes umfasst:
- Erzeugen einer dritten Lamelle (809), die eine dritte Seite (806) der Öffnung (803)
umfasst, wobei die dritte Seite (806) und die zweite Seite (805) einander gegenüber
angeordnet sind und die erste Seite (804) zwischen der zweiten Seite (805) und der
dritten Seite (806) angeordnet ist;
- Führen des zweiten Ladungsträgerstrahls (312) über die dritte Seite (806) des Objekts
(304), Detektieren sechster Interaktionspartikel unter Verwendung der ersten Detektionseinheit
(317, 703), wobei die sechsten Interaktionspartikel entstehen, wenn der zweite Ladungsträgerstrahl
(312) auf die dritte Seite (806) des Objekts (304) einwirkt, Erzeugen eines vierten
Detektionssignals unter Verwendung der ersten Detektionseinheit (317, 703) und Erzeugen
eines vierten Bildes der dritten Seite (806) des Objekts (304) unter Verwendung des
vierten Detektionssignals, wobei das vierte Bild vierte Bildpixel umfasst und jedes
Pixel der vierten Bildpixel vierte Bilddaten umfasst;
- Analysieren der dritten Lamelle (809) durch Identifizieren dritter Materialeigenschaften
der dritten Lamelle (809), die jedem Pixel der vierten Bildpixel zugeordnet sind,
unter Verwendung von Folgendem: des ersten Ladungsträgerstrahls (329) und/oder des
zweiten Ladungsträgerstrahls (312), und Detektieren von Folgendem: siebter Interaktionspartikel
und/oder einer dritten Interaktionsstrahlung unter Verwendung der zweiten Detektionseinheit
(336, 500); und
- Erzeugen dritter gefilterter Daten für jedes Pixel der vierten Bildpixel unter Verwendung
mindestens eines dritten Bildfilters zum Verarbeiten der vierten Bilddaten für jedes
Pixel der vierten Bildpixel; wobei
- der Schritt des Identifizierens von Daten, die den ersten Bilddaten gleich oder
ähnlich sind, für jedes Pixel der ersten Bildpixel des ersten Bildes auch ein Identifizieren
unter den Folgenden umfasst: den vierten Bilddaten jedes Pixels der vierten Bildpixel
und den dritten gefilterten Daten für jedes Pixel der vierten Bildpixel; und
- der Schritt des Zuweisens von Materialeigenschaften zu mindestens einem Pixel der
ersten Bildpixel des ersten Bildes ein Zuweisen der dritten Materialeigenschaften
umfasst, wenn: die identifizierten vierten Bilddaten eines Pixels der vierten Bildpixel
und/oder die identifizierten dritten gefilterten Daten für ein Pixel der vierten Bildpixel
gleich oder ähnlich den ersten Bilddaten des mindestens einen Pixels der ersten Bildpixel
sind.
3. Verfahren nach Anspruch 1, wobei der Schritt des Identifizierens gleicher oder ähnlicher
Daten ein Vergleichen der ersten Bilddaten für jedes Pixel der ersten Bildpixel des
ersten Bildes mit Folgendem umfasst: den zweiten Bilddaten jedes Pixels der zweiten
Bildpixel und/oder den dritten Bilddaten jedes Pixels der dritten Bildpixel und/oder
den ersten gefilterten Daten für jedes Pixel der zweiten Bildpixel und/oder den zweiten
gefilterten Daten für jedes Pixel der dritten Bildpixel.
4. Verfahren nach Anspruch 1, das ferner Folgendes umfasst:
(i)Analysieren der ersten Lamelle (807) unter Verwendung von Folgendem: Röntgenstrahlen
und/oder Kathodolumineszenzlicht; und/oder
(ii) Analysieren der zweiten Lamelle (808) unter Verwendung von Folgendem: Röntgenstrahlen
und/oder Kathodolumineszenzlicht.
5. Verfahren nach Anspruch 1, das ferner Folgendes umfasst:
(i)Analysieren der ersten Lamelle (807) unter Verwendung von Folgendem: EDX und/oder
WDX und/oder EBSD und/oder TKD; und/oder
(ii) Analysieren der zweiten Lamelle (808) unter Verwendung von Folgendem: EDX und/oder
WDX und/oder EBSD und/oder TKD.
6. Verfahren nach Anspruch 1, wobei der Schritt des Identifizierens gleicher oder ähnlicher
Daten ein Verwenden eines Lernverfahrens zur Klassifizierung umfasst.
7. Verfahren nach Anspruch 6, wobei der Schritt des Identifizierens gleicher oder ähnlicher
Daten ein Verwenden von Folgendem umfasst: eines Zufallsentscheidungswalds und/oder
eines Zuordnungsregellernens und/oder eines künstlichen neuronalen Netzes und/oder
einer Support-Vektor-Maschine und/oder eines Bayes'sehen Netzes.
8. Verfahren nach Anspruch 1, das ferner Folgendes umfasst: Verwenden eines der folgenden
Filter als das Bildfilter: eines Gabor-Filters und/oder eines Mittelwertfilters und/oder
eines Varianzfilters und/oder eines histogrammorientierten Gradientenfilters und/oder
eines Maximumfilters und/oder eines Minimumfilters und/oder eines Kuwahara-Filters.
9. Computerprogrammprodukt, das einen Programmcode enthält, der ausgelegt ist, in einen
Prozessor (701) geladen zu werden, und der, wenn er ausgeführt wird, eine Ladungsträgerstrahlvorrichtung
(300) derart steuert, dass ein Verfahren nach Anspruch 1 ausgeführt wird.
10. Ladungsträgerstrahlvorrichtung (300) zum Analysieren eines Objekts (304), die Folgendes
umfasst:
- einen ersten Ladungsträgerstrahlgenerator (330) zum Erzeugen eines ersten Ladungsträgerstrahls
(329), der erste Ladungsträger aufweist,
- eine erste Objektivlinse (334) zum Fokussieren des ersten Ladungsträgerstrahls (329)
auf das Objekt (304),
- einen zweiten Ladungsträgerstrahlgenerator (302) zum Erzeugen eines zweiten Ladungsträgerstrahls
(312), der zweite Ladungsträger besitzt,
- eine zweite Objektivlinse (319) zum Fokussieren des zweiten Ladungsträgerstrahls
(312) auf das Objekt (304),
- eine erste Detektionseinheit (317, 703) zum Detektieren von Interaktionspartikeln
und eine zweiten Detektionseinheit (336, 500) zum Detektieren von Folgendem: Interaktionspartikeln
und/oder Interaktionsstrahlung, wobei die Interaktionspartikel und die Interaktionsstrahlung
auftreten, wenn: (i) der erste Ladungsträgerstrahl (329) und/oder (ii) der zweite
Ladungsträgerstrahl (312) auf das Objekt (304) einwirken, und
- einen Prozessor (701) in den ein Computerprogrammprodukt nach Anspruch 9 geladen
ist.
11. Ladungsträgerstrahlvorrichtung (300) nach Anspruch 10, die ferner eines der folgenden
Merkmale umfasst:
- ein erster Detektor umfasst die erste Detektoreinheit (317, 703) und ein zweiter
Detektor umfasst die zweite Detektoreinheit (336, 500); und
- ein einzelner Detektor umfasst die erste Detektoreinheit (317, 703) und die zweite
Detektoreinheit (336, 500).
12. Ladungsträgerstrahlvorrichtung (300) nach Anspruch 10, wobei die Ladungsträgerstrahlvorrichtung
(300) Folgendes ist: eine Elektronenstrahlvorrichtung und/oder eine Ionenstrahlvorrichtung.
1. Procédé d'analyse d'un objet (304) au moyen d'un dispositif à faisceau de particules
chargées (300),
- le dispositif à faisceau de particules chargées (300) comprenant un premier générateur
de faisceau de particules chargées (330) destiné à générer un premier faisceau de
particules chargées (329) comportant des premières particules chargées, une première
lentille objective (334) destinée à concentrer le premier faisceau de particules chargées
(329) sur l'objet (304), un deuxième générateur de faisceau de particules chargées
(307) destiné à générer un deuxième faisceau de particules chargées (312) comportant
des deuxièmes particules chargées, une deuxième lentille objective (319) destinée
à concentrer le deuxième faisceau de particules chargées (312) sur l'objet (304),
une première unité de détection (317, 703) et une deuxième unité de détection (336,
500),
le procédé comprenant les étapes suivantes :
- guidage du premier faisceau de particules chargées (329) au-dessus de l'objet (304),
élimination de matériau de l'objet (304) au moyen du premier faisceau de particules
chargées (329), mise à nu d'une première surface (800) de l'objet (304) lors de l'élimination
du matériau de l'objet (304), guidage du deuxième faisceau de particules chargées
(312) au-dessus de la première surface (800) de l'objet (304), détection de premières
particules d'interaction au moyen de la première unité de détection (317, 703), les
premières particules d'interaction apparaissant lorsque le deuxième faisceau de particules
chargées (312) frappe la première surface (800), génération d'un premier signal de
détection au moyen de la première unité de détection (317, 703) et génération d'une
première image de la première surface (800) de l'objet (304) au moyen du premier signal
de détection, la première image comprenant des premiers pixels d'image, chaque pixel
des premiers pixels d'image comprenant des premières données d'image ;
- guidage du premier faisceau de particules chargées (329) au-dessus de l'objet (304),
élimination de matériau comprenant la première surface (800) de l'objet (304) au moyen
du premier faisceau de particules chargées (329), mise à nu d'une deuxième surface
(801) de l'objet (304) lors de l'élimination du matériau de l'objet (304), guidage
du deuxième faisceau de particules chargées (312) au-dessus de la deuxième surface
(801) de l'objet (304), détection de deuxièmes particules d'interaction au moyen de
la première unité de détection (317, 703), les deuxièmes particules d'interaction
apparaissant lorsque le deuxième faisceau de particules chargées (312) frappe la deuxième
surface (800), génération d'un deuxième signal de détection au moyen de la première
unité de détection (317, 703) et génération d'une deuxième image de la deuxième surface
(801) de l'objet (304) au moyen du deuxième signal de détection, la deuxième image
comprenant des deuxièmes pixels d'image, chaque pixel des deuxièmes pixels d'image
comprenant des deuxièmes données d'image, une ouverture (803) étant générée lors de
l'élimination du matériau de l'objet (304) de manière à mettre à nu la première surface
(800) et la deuxième surface (801) de l'objet (304), l'ouverture (803) comprenant
un premier côté (804) comprenant la deuxième surface (801) et un deuxième côté (805,
806) s'étendant depuis la deuxième surface (804) de l'objet (304) dans une direction
s'éloignant de la deuxième surface (801) ;
- génération d'une première lamelle (807) comprenant le premier côté (804) de l'ouverture
(800) comportant la première surface (801) comme une surface extérieure, et génération
d'une deuxième lamelle (807, 809) comprenant le deuxième côté (805, 806) de l'ouverture
(800) ;
- guidage du deuxième faisceau de particules chargées (312) au-dessus du deuxième
côté (805, 806) de l'objet (304), détection de troisièmes particules d'interaction
au moyen de la première unité de détection (317, 703), les troisièmes particules d'interaction
apparaissant lorsque le deuxième faisceau de particules chargées (312) frappe le deuxième
côté (805, 806) de l'objet (304), génération d'un troisième signal de détection au
moyen de la première unité de détection (317, 703) et génération d'une troisième image
du deuxième côté (805, 806) de l'objet (304) au moyen du troisième signal de détection,
la troisième image comprenant des troisièmes pixels d'image, chaque pixel des troisièmes
pixels d'image comprenant des troisièmes données d'image ;
- analyse de la première lamelle (807) par identification de premières caractéristiques
de matériau de la première lamelle (807) associées à chaque pixel des deuxièmes pixels
d'image au moyen du premier faisceau de particules chargées (329) et/ou du deuxième
faisceau de particules chargées (312), et détection de quatrièmes particules d'interaction
et/ou d'un premier rayonnement d'interaction au moyen de la deuxième unité de détection
(336, 500) ;
- analyse de la deuxième lamelle (808) par identification de deuxièmes caractéristiques
de matériau de la deuxième lamelle associées à chaque pixel des troisièmes pixels
d'image au moyen du premier faisceau de particules chargées (329) et/ou du deuxième
faisceau de particules chargées (312), et détection de cinquièmes particules d'interaction
et/ou d'un deuxième rayonnement d'interaction au moyen de la deuxième unité de détection
(336, 500) ;
- génération de premières données filtrées pour chaque pixel des deuxièmes pixels
d'image au moyen d'au moins un premier filtre d'image pour le traitement des deuxièmes
données d'image pour chaque pixel des deuxièmes pixels d'image, et génération de deuxièmes
données filtrées pour chaque pixel des troisièmes pixels d'image au moyen d'au moins
un deuxième filtre d'image pour le traitement des troisièmes données d'image pour
chaque pixel des troisièmes pixels d'image ;
- identification de données identiques ou similaires aux premières données d'image
pour chaque pixel des premiers pixels d'image de la première image parmi : les deuxièmes
données d'image de chaque pixel des deuxièmes pixels d'image, les troisièmes données
d'image de chaque pixel des troisièmes pixels d'image, les premières données filtrées
pour chaque pixel des deuxièmes pixels d'image et les deuxièmes données filtrées pour
chaque pixel des troisièmes pixels d'image ; et
- assignation de caractéristiques de matériau à au moins un pixel des premières pixels
d'image de la première image,
(i) les premières caractéristiques de matériau étant assignées si les deuxièmes données
d'image identifiées d'un pixel des deuxièmes pixels d'image et/ou les premières données
filtrées identifiées pour un pixel des deuxièmes pixels d'image sont identiques ou
similaires aux premières données d'image de l'au moins un pixel des premiers pixels
d'image ; et
(ii) les deuxièmes caractéristiques de matériau étant assignées si les troisièmes
données d'image identifiées d'un pixel des troisièmes pixels d'image et/ou les deuxièmes
données filtrées identifiées pour un pixel des troisièmes pixels d'image sont identiques
ou similaires aux premières données d'image de l'au moins un pixel des premiers pixels
d'image.
2. Procédé selon la revendication 1, le procédé comprenant en outre :
- génération d'une troisième lamelle (809) comprenant un troisième côté (806) de l'ouverture
(803), le troisième côté (806) et le deuxième côté (805) étant agencés en regard l'un
de l'autre et le premier côté (804) étant agencé entre le deuxième côté (805) et le
troisième côté (806) ;
- guidage du deuxième faisceau de particules chargées (312) au-dessus du troisième
côté (806) de l'objet (304), détection de sixièmes particules d'interaction au moyen
de la première unité de détection (317, 703), les sixièmes particules d'interaction
apparaissant lorsque le deuxième faisceau de particules chargées (312) frappe le troisième
côté (806) de l'objet (304), génération d'un quatrième signal de détection au moyen
de la première unité de détection (317, 703) et génération d'une quatrième image du
troisième côté (806) de l'objet (304) au moyen du quatrième signal de détection, la
quatrième image comprenant des quatrièmes pixels d'image, chaque pixel des quatrièmes
pixels d'image comprenant des quatrièmes données d'image ;
- analyse de la troisième lamelle (809) par identification de troisièmes caractéristiques
de matériau de la troisième lamelle (809) associées à chaque pixel des quatrièmes
pixels d'image au moyen du premier faisceau de particules chargées (329) et/ou du
deuxième faisceau de particules chargées (312), et détection de septièmes particules
d'interaction et/ou d'un troisième rayonnement d'interaction au moyen de la deuxième
unité de détection (336, 500) ;
- génération de troisièmes données filtrées pour chaque pixel des quatrièmes pixels
d'image au moyen d'au moins un troisième filtre d'image pour le traitement des quatrièmes
données d'image pour chaque pixel des quatrièmes pixels d'image ;
- l'étape d'identification de données identiques ou similaires aux premières données
d'image pour chaque pixel des premiers pixels d'image de la première image comprenant
également l'identification parmi : les quatrièmes données d'image de chaque pixel
des quatrièmes pixels d'image et les troisièmes données filtrées pour chaque pixel
des quatrièmes pixels d'image ;
- l'étape d'assignation de caractéristiques de matériau à au moins un pixel des premiers
pixels d'image de la première image comprenant l'assignation des troisièmes caractéristiques
de matériau si les quatrièmes données d'image identifiées d'un pixel des quatrièmes
pixels d'image et/ou les troisièmes données filtrées identifiées pour un pixel des
quatrièmes pixels d'image sont identiques ou similaires aux premières données d'image
de l'au moins un pixel des premiers pixels d'image.
3. Procédé selon la revendication 1, dans lequel l'étape d'identification de données
identiques ou similaires comprend la comparaison des premières données d'image pour
chaque pixel des premiers pixels d'image de la première image aux deuxièmes données
d'image de chaque pixel des deuxièmes pixels d'image et/ou aux troisièmes données
d'image de chaque pixel des troisièmes pixels d'image et/ou aux premières données
filtrées pour chaque pixel des deuxièmes pixels d'image et/ou aux deuxièmes données
filtrées pour chaque pixel des troisièmes pixels d'image.
4. Procédé selon la revendication 1, comprenant en outre :
(i) l'analyse de la première lamelle (807) au moyen de rayons X et/ou d'une lumière
par cathodoluminescence ; et/ou
(ii) l'analyse de la deuxième lamelle (808) au moyen de rayons X et/ou d'une lumière
par cathodoluminescence.
5. Procédé selon la revendication 1, comprenant en outre :
(i) l'analyse de la première lamelle (807) par EDX et/ou WDX et/ou EBSD et/ou TKD
; et/ou
(ii) l'analyse de la deuxième lamelle (808) par EDX et/ou WDX et/ou EBSD et/ou TKD.
6. Procédé selon la revendication 1, dans lequel l'étape d'identification de données
identiques ou similaires comprend l'utilisation d'une méthode d'apprentissage à des
fins de classification.
7. Procédé selon la revendication 6, dans lequel l'étape d'identification de données
identiques ou similaires comprend l'utilisation d'une forêt aléatoire d'arbres décisionnels
et/ou d'un apprentissage de règles d'association et/ou d'un réseau de neurones artificiels
et/ou d'une machine à vecteurs de support et/ou d'un réseau de Bayes.
8. Procédé selon la revendication 1, comprenant en outre : l'utilisation d'au moins un
des filtres suivants comme filtre d'image : un filtre de Gabor, un filtre de moyenne,
un filtre de variance, un filtre de gradient orienté histogramme, un filtre maximum,
un filtre minimum et un filtre de Kuwahara.
9. Produit-programme d'ordinateur comprenant un code de programme qui est adapté à être
chargé dans un processeur (701) et qui, lors de son exécution, commande un dispositif
à faisceau de particules chargées (300) de manière à mettre en œuvre un procédé selon
la revendication 1.
10. Dispositif à faisceau de particules chargées (300) destiné à analyser un objet (304),
comprenant
- un premier générateur de faisceau de particules chargées (330) destiné à générer
un premier faisceau de particules chargées (329) comportant des premières particules
chargées,
- une première lentille objective (334) destinée à concentrer le premier faisceau
de particules chargées (329) sur l'objet (304),
- un deuxième générateur de faisceau de particules chargées (302) destiné à générer
un deuxième faisceau de particules chargées (312) comportant des deuxièmes particules
chargées,
- une deuxième lentille objective (319) destinée à concentrer le deuxième faisceau
de particules chargées (312) sur l'objet (304),
- une première unité de détection (317, 703) destinée à détecter des particules d'interaction
et une deuxième unité de détection (336, 500) destinée à détecter des particules d'interaction
et/ou un rayonnement d'interaction, les particules d'interaction et le rayonnement
d'interaction apparaissant lorsque (i) le premier faisceau de particules chargées
(329) et/ou (ii) le deuxième faisceau de particules chargées (312) frappent/frappe
l'objet (304), et
- un processeur (701) dans lequel est chargé un produit-programme d'ordinateur selon
la revendication 9.
11. Dispositif à faisceau de particules chargées (300) selon la revendication 10, comprenant
en outre l'une des caractéristiques suivantes :
- un premier détecteur comprend la première unité détectrice (317, 703) et un deuxième
détecteur comprend la deuxième unité détectrice (336, 500) ; et
- un unique détecteur comprend la première unité détectrice (317, 703) et la deuxième
unité détectrice (336, 500).
12. Dispositif à faisceau de particules chargées (300) selon la revendication 10, le dispositif
à faisceau de particules chargées (300) prenant la forme d'un dispositif à faisceau
d'électrons et/ou d'un dispositif à faisceau d'ions.