U.S. patent application number 17/099476 was filed with the patent office on 2021-03-25 for multi-column scanning electron microscopy system.
The applicant listed for this patent is KLA Corporation. Invention is credited to John Gerling, Mehran Nasser Ghodsi, Robert Haynes, Tomas Plettner, Aron Welk.
Application Number | 20210090844 17/099476 |
Document ID | / |
Family ID | 1000005251641 |
Filed Date | 2021-03-25 |
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United States Patent
Application |
20210090844 |
Kind Code |
A1 |
Haynes; Robert ; et
al. |
March 25, 2021 |
MULTI-COLUMN SCANNING ELECTRON MICROSCOPY SYSTEM
Abstract
A multi-column scanning electron microscopy (SEM) system
includes a column assembly, where the column assembly includes a
first substrate array assembly and at least a second substrate
array assembly. The system also includes a source assembly, the
source assembly including two or more illumination sources
configured to generate two or more electron beams and two or more
sets of a plurality of positioners configured to adjust a position
of a particular illumination source of the two or more illumination
sources in a plurality of directions. The system also includes a
stage configured to secure a sample, where the column assembly
directs at least a portion of the two or more electron beams onto a
portion of the sample.
Inventors: |
Haynes; Robert; (Pleasanton,
CA) ; Welk; Aron; (Tracy, CA) ; Plettner;
Tomas; (San Ramon, CA) ; Gerling; John;
(Livermore, CA) ; Ghodsi; Mehran Nasser;
(Hamilton, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KLA Corporation |
Milpitas |
CA |
US |
|
|
Family ID: |
1000005251641 |
Appl. No.: |
17/099476 |
Filed: |
November 16, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15612862 |
Jun 2, 2017 |
10840056 |
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17099476 |
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62455955 |
Feb 7, 2017 |
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62454715 |
Feb 3, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01J 37/02 20130101;
H01J 37/285 20130101; H01J 2237/1205 20130101; H01J 37/14 20130101;
H01J 37/1472 20130101; H01J 2237/28 20130101; H01J 37/147 20130101;
H01J 37/28 20130101; H01J 37/10 20130101; H01J 37/1474
20130101 |
International
Class: |
H01J 37/10 20060101
H01J037/10; H01J 37/02 20060101 H01J037/02; H01J 37/14 20060101
H01J037/14; H01J 37/147 20060101 H01J037/147; H01J 37/28 20060101
H01J037/28; H01J 37/285 20060101 H01J037/285 |
Claims
1. A multi-column scanning electron microscopy (SEM) system
comprising: a column assembly comprising: a first substrate array
assembly; and at least a second substrate array assembly, wherein a
substrate array of at least one of the first substrate array
assembly or the at least a second substrate array assembly
includes: a composite substrate formed from a plurality of
substrate layers, wherein the composite substrate includes a hole
for each of the two or more electron beams; a plurality of
electrical components embedded within the plurality of substrate
layers; at least one ground bonding pad coupled to at least one of
a top surface or a bottom surface of the composite substrate; at
least one signal bonding pad coupled to at least one of the top
surface or the bottom surface of the composite substrate; and a
plurality of column electron-optical elements, wherein the
plurality of column electron-optical elements are bonded to the
composite substrate over the plurality of holes in the composite
substrate, wherein each of the plurality of column electron-optical
elements are bonded to a particular ground bonding pad and a
particular signal bonding pad coupled to at least one of the top
surface or the bottom surface of the composite substrate; a source
assembly comprising: two or more electron beam sources configured
to generate two or more electron beams, wherein each of the two or
more electron beam sources is configured to generate an electron
beam of the two or more electron beams; and two or more sets of a
plurality of positioners, wherein each set of the plurality of
positioners is configured to adjust a position of a particular
electron beam source of the two or more electron beam sources in a
plurality of directions; and a stage configured to secure a sample,
wherein the column assembly is configured to direct at least a
portion of the two or more electron beams onto a portion of the
sample.
2. The system in claim 1, wherein the source assembly further
comprises: two or more sets of source electron-optical elements,
wherein each of the two or more sets of source electron-optical
elements is configured to direct at least a portion of an electron
beam of the two or more electron beams through the column
assembly.
3. The system in claim 1, further comprising: two or more detector
assemblies, wherein the two or more detector assemblies are
positioned to detect electrons emitted or scattered from the
surface of the sample.
4. The system in claim 3, wherein the two or more detector
assemblies are positioned within the column assembly.
5. The system in claim 1, wherein each of the two or more electron
beam sources comprises: at least one of a Schottky emitter device,
a carbon nanotube (CNT) emitter, a nanostructured carbon film
emitter, or a Muller-type emitter.
6. The system in claim 1, wherein at least one of the first
substrate array assembly or the at least a second substrate array
assembly includes two or more substrate arrays, wherein at least
one metal shield is positioned between the two or more substrate
arrays.
7. The system in claim 1, wherein the first substrate array
assembly is arranged in a first substrate array stack and mounted
in a first frame, wherein the at least a second substrate array
assembly is arranged in at least a second substrate array stack and
mounted in at least a second frame, wherein the first frame and the
at least a second frame are coupled.
8. The system in claim 7, wherein at least one of arranging the
first substrate array assembly, arranging the second substrate
array stack, or coupling the first frame and the at least a second
frame includes aligning to compensate for at least one of an offset
distance in an x-direction, an offset distance in a y-direction, or
an offset rotation angle.
9. The system in claim 1, wherein the first substrate array
assembly is arranged in a first bonded substrate array stack,
wherein the at least a second substrate array assembly is arranged
in at least a second bonded substrate array stack, wherein the
first bonded substrate array stack and the at least a second bonded
substrate array stack are bonded.
10. The system in claim 9, wherein at least one of arranging the
first substrate array assembly, arranging the at least a second
substrate array, or bonding the first bonded substrate array stack
and the at least a second bonded substrate array stack includes
aligning to compensate for at least one of an offset distance in an
x-direction, an offset distance in a y-direction, or an offset
rotation angle.
11. The system in claim 1, wherein the first substrate array
assembly is arranged in a first substrate array stack and mounted
in a frame, wherein the at least a second substrate array assembly
is arranged in at least a second substrate array stack and mounted
in the same frame.
12. The system in claim 11, wherein at least one of arranging the
first substrate array assembly or arranging the second substrate
array stack includes aligning to compensate for at least one of an
offset distance in an x-direction, an offset distance in a
y-direction, or an offset rotation angle.
13. The system in claim 1, wherein each set of the plurality of
positioners is configured to adjust a position of a particular
illumination source in a plurality of directions, the plurality of
directions including at least one of an x-direction, a y-direction,
or a z-direction.
14. The system in claim 1, wherein the plurality of electrical
components embedded within the plurality of substrate layers
include at least one of one or more ground traces, one or more
signal traces, one or more ground vias, or one or more signal
vias.
15. The system in claim 14, wherein at least one of the one or more
ground traces, the one or more ground vias, the one or more signal
traces, or the one or more signal vias are embedded in the
plurality of substrate layers prior to forming the composite
substrate.
16. The system in claim 14, wherein the one or more ground traces
are electrically coupled to the at least one ground bonding pad
with the one or more ground vias.
17. The system in claim 14, wherein the one or more signal traces
are electrically coupled to the at least one signal bonding pad
with the one or more signal vias.
18. A method comprising: forming a plurality of substrate arrays,
wherein forming the substrate array of the plurality of substrate
array includes: embedding one or more components within a plurality
of substrate layers; forming a composite substrate from the
plurality of substrate layers; boring a plurality of holes in the
composite substrate; coupling at least one ground bonding pad to at
least one of a top surface or a bottom surface of the composite
substrate; coupling at least one signal bonding pad to at least one
of the top surface or the bottom surface of the composite
substrate; and bonding a plurality of column electron-optical
elements to a particular ground bonding pad and a particular signal
bonding pad coupled to at least one of the top surface or the
bottom surface of the composite substrate, wherein each of the
plurality of column electron-optical elements are positioned over
the plurality of holes in the composite substrate; sorting the
plurality of substrate arrays into a first substrate array assembly
and at least a second substrate array assembly; and forming a
column assembly from the first substrate array assembly and the at
least a second substrate array assembly.
19. The method in claim 18, wherein at least some of the plurality
of column electron-optical elements are partially fabricated via a
first set of fabrication processes prior to bonding the at least
some of the plurality of column electron-optical elements to a
particular ground bonding pad and a particular signal bonding pad,
wherein the at least some of the plurality of column
electron-optical elements are fully fabricated via a second set of
fabrication processes after bonding the at least some of the
plurality of column electron-optical elements to the particular
ground bonding pad and the particular signal bonding pad.
20. The method in claim 19, wherein the first set of fabrication
processes includes: boring a hole based on at least one critical
tolerance in the at least some of the plurality of column
electron-optical elements; and cutting a plurality of slots in the
at least some of the plurality of column electron-optical elements,
wherein the plurality of slots includes a first slot and at least a
second slot, wherein the first slot and the at least a second slot
pass through a portion of the hole, wherein the first slot and the
at least a second slot do not extend to the edge of the at least
some of the plurality of column electron-optical elements.
21. The method in claim 20, wherein the at least one critical
tolerance includes at least one of a bore size or a bore shape.
22. The method in claim 20, wherein the second set of fabrication
processes includes: cutting the plurality of slots to extend to the
edge of the at least some of the plurality of column
electron-optical elements.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to and claims benefit of
the earliest available effective filing date from the following
applications: The present application constitutes a continuation
application of U.S. patent application Ser. No. 15/612,862, filed
on Jun. 2, 2017, which is a regular (non-provisional) patent
application of U.S. Provisional Patent Application Ser. No.
62/454,715, filed Feb. 3, 2017, as well as U.S. Provisional Patent
Application Ser. No. 62/455,955, filed Feb. 7, 2017, whereby each
of the above-listed patent applications is incorporated herein by
reference in their entirety.
TECHNICAL FIELD
[0002] The present invention generally relates to wafer and
photomask/reticle inspection and review and, more particularly, to
a column assembly for a multi-column scanning electron microscopy
system for use during wafer and photomask/reticle inspection and
review.
BACKGROUND
[0003] The fabrication of semiconductor devices, such as logic and
memory devices, typically includes processing a semiconductor
device using a large number of semiconductor fabrication processes
to form various features and multiple levels of the semiconductor
devices. Some fabrication processes utilize photomasks/reticles to
print features on a semiconductor device such as a wafer. As
semiconductor device size becomes smaller and smaller, it becomes
critical to develop enhanced inspection and review devices and
procedures to increase the resolution, speed, and throughput of
wafer and photomask/reticle inspection processes.
[0004] One inspection technology includes electron beam based
inspection such as scanning electron microscopy (SEM). In some
instances, scanning electron microscopy is performed by splitting a
single electron beam into numerous beams and utilizing a single
electron-optical column to individually tune and scan the numerous
beams (e.g. a multi-beam SEM system). However, splitting a beam
into an N number of lower current beams traditionally reduces the
resolution of the multi-beam SEM system, as the N number of beams
are tuned on a global level and individual images cannot be
optimized. Additionally, splitting a beam into an N number of beams
results in needing more scans and averages to obtain an image,
which reduces the speed and throughput of the multi-beam SEM
system. These issues increase with an increase in electron-optical
column array size.
[0005] In other instances, scanning electron microscopy is
performed via an SEM system which includes an increased number of
electron-optical columns (e.g. a multi-column SEM system).
Traditionally, these electron-optical columns are individual stacks
of metal, ceramic rings, and electromagnets. These individual
stacks are too large to be placed together with an ideal pitch for
optimizing wafer, photomask/reticle scan speed, and cannot be
miniaturized to allow for packing a significant number of
electron-optical columns in a usable area, resulting in a
limitation of the number of stacks in the multi-column SEM system
(e.g. four stacks). Additionally, having individual stacks results
in issues with electron-optical column matching, cross talk between
the columns, and errant charging.
[0006] Further, size limitations exist when fabricating individual
components such as multipole beam deflectors (e.g. quadrupole or
octupole beam deflectors) elements for electron-optical columns as
the electron-optical columns become smaller and smaller. One method
of fabricating multipole beam deflectors includes fabricating an
array of critical tolerance lens bores and radial slots in metal
vias that segment and electrically isolate the poles of the
multipole beam deflector. As the electron-optical column size
decreases, multipole beam deflectors become more susceptible to
fabrication errors that may potentially render the entire element
unusable, which subsequently reduces the yield of the fabrication
process. Another method of fabricating multipole beam deflectors
includes pre-fabricating individual poles of the multipole beam
deflectors and then bonding the individual poles together, either
individually in pairs or via an alignment fixture. This method is
limiting in terms of fabrication time and limited to select
fabrication methods due to the close proximity of the individual
poles. Additionally, this method is susceptible to errors in
maintaining fabrication tolerances, as the tolerances would be
affected by the relative placement errors of the individual poles
of the multipole beam deflector. Further, maintaining at a desired
critical tolerance when aligning and bonding the individual poles
of the multipole beam deflector would require precise, miniscule
tooling. This tooling may add a significant thermal mass during the
bonding process, and the space required for the tooling may limit
subsequent electron-optical column spacing.
[0007] Therefore, it would be advantageous to provide a system that
cures the shortcomings described above.
SUMMARY
[0008] A substrate array is disclosed, in accordance with one or
more embodiments of the present disclosure. In one embodiment, the
substrate array includes a composite substrate formed from a
plurality of substrate layers. In another embodiment, the composite
substrate includes a plurality of holes. In another embodiment, the
substrate array includes a plurality of electrical components
embedded within the plurality of substrate layers. In another
embodiment, the substrate array includes at least one ground
bonding pad coupled to at least one of a top surface or a bottom
surface of the composite substrate. In another embodiment, the
substrate array includes at least one signal bonding pad coupled to
at least one of the top surface or the bottom surface of the
composite substrate. In another embodiment, the substrate array
includes a plurality of column electron-optical elements. In
another embodiment, the plurality of column electron-optical
elements are positioned over the plurality of holes in the
composite substrate. In another embodiment, each of the plurality
of column electron-optical elements are bonded to a particular
ground bonding pad and a particular signal bonding pad coupled to
at least one of the top surface or the bottom surface of the
composite substrate.
[0009] A multi-column scanning electron microscopy (SEM) system is
disclosed, in accordance with one or more embodiments of the
present disclosure. In one embodiment, the system includes a column
assembly. In another embodiment, the column assembly includes a
first substrate array assembly. In another embodiment, the column
assembly includes at least a second substrate array assembly. In
another embodiment, at least one of the first substrate array
assembly or the at least a second substrate array assembly includes
a substrate array. In another embodiment, the substrate array
includes a composite substrate formed from a plurality of substrate
layers. In another embodiment, the composite substrate includes a
plurality of holes. In another embodiment, the substrate array
includes a plurality of electrical components embedded within the
plurality of substrate layers. In another embodiment, the substrate
array includes at least one ground bonding pad coupled to at least
one of a top surface or a bottom surface of the composite
substrate. In another embodiment, the substrate array includes at
least one signal bonding pad coupled to at least one of the top
surface or the bottom surface of the composite substrate. In
another embodiment, the substrate array includes a plurality of
column electron-optical elements. In another embodiment, the
plurality of column electron-optical elements are positioned over
the plurality of holes in the composite substrate. In another
embodiment, each of the plurality of column electron-optical
elements are bonded to a particular ground bonding pad and a
particular signal bonding pad coupled to at least one of the top
surface or the bottom surface of the composite substrate.
[0010] In another embodiment, the system includes a source
assembly. In another embodiment, the source assembly includes two
or more electron beam sources configured to generate two or more
electron beams. In another embodiment, each of the two or more
electron beam sources is configured to generate an electron beam.
In another embodiment, the source assembly includes two or more
sets of a plurality of positioners. In another embodiment, each set
of the plurality of positioners is configured to adjust a position
of a particular illumination source of the two or more illumination
sources in a plurality of directions. In another embodiment, the
system includes a stage configured to secure a sample. In another
embodiment, the column assembly is configured to direct at least a
portion of the two or more electron beams onto a portion of the
sample.
[0011] A method is disclosed, in accordance with one or more
embodiments of the present disclosure. In one embodiment, the
method may include, but is not limited to, forming a plurality of
substrate arrays. In another embodiment, forming the substrate
array of the plurality of substrate arrays may include, but is not
limited to, embedding one or more components within a plurality of
substrate layers. In another embodiment, forming the substrate
array of the plurality of substrate arrays may include, but is not
limited to, forming a composite substrate from the plurality of
substrate layers/In another embodiment, forming the substrate array
of the plurality of substrate arrays may include, but is not
limited to, boring a plurality of holes in the composite substrate.
In another embodiment, forming the substrate array of the plurality
of substrate arrays may include, but is not limited to, coupling at
least one ground bonding pad to at least one of a top surface or a
bottom surface of the composite substrate. In another embodiment,
forming the substrate array of the plurality of substrate arrays
may include, but is not limited to, coupling at least one signal
bonding pad to at least one of the top surface or the bottom
surface of the composite substrate. In another embodiment, forming
the substrate array of the plurality of substrate arrays may
include, but is not limited to, bonding a plurality of column
electron-optical elements to a particular ground bonding pad and a
particular signal bonding pad coupled to at least one of the top
surface or the bottom surface of the composite substrate. In
another embodiment, each of the plurality of column
electron-optical elements are positioned over the plurality of
holes in the composite substrate.
[0012] In another embodiment, the method may include, but is not
limited to, sorting the plurality of substrate arrays into a first
substrate array assembly and at least a second substrate array
assembly. In another embodiment, the method may include, but is not
limited to, forming a column assembly from the first substrate
array assembly and the at least a second substrate array
assembly.
[0013] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not necessarily restrictive of the
present disclosure. The accompanying drawings, which are
incorporated in and constitute a part of the characteristic,
illustrate subject matter of the disclosure. Together, the
descriptions and the drawings serve to explain the principles of
the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The numerous advantages of the disclosure may be better
understood by those skilled in the art by reference to the
accompanying figures in which:
[0015] FIG. 1 is a simplified schematic view of a multi-column
scanning electron microscopy (SEM) system equipped with a column
assembly, in accordance with one or more embodiments of the present
disclosure.
[0016] FIG. 2A is a cross-section view of a column assembly for a
multi-column SEM system, in accordance with one or more embodiments
of the present disclosure.
[0017] FIG. 2B is a substrate array for a column assembly, in
accordance with one or more embodiments of the present
disclosure.
[0018] FIG. 2C is a cross-section view of a substrate array for a
column assembly, in accordance with one or more embodiments of the
present disclosure.
[0019] FIG. 3A is an isometric view of a partially-fabricated
multipole beam deflector, in accordance with one or more
embodiments of the present disclosure.
[0020] FIG. 3B is a bottom view of a partially-fabricated multipole
beam deflector, in accordance with one or more embodiments of the
present disclosure.
[0021] FIG. 3C is a cross-section view of a partially-fabricated
multipole beam deflector, in accordance with one or more
embodiments of the present disclosure.
[0022] FIG. 3D is a substrate array equipped with fully-fabricated
multipole beam deflectors, in accordance with one or more
embodiments of the present disclosure.
[0023] FIG. 4 is a method for fabricating a column assembly for a
multi-column SEM system, in accordance with one or more embodiments
of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Reference will now be made in detail to the subject matter
disclosed, which is illustrated in the accompanying drawings.
[0025] Referring generally to FIGS. 1-4, a multi-column scanning
electron microscopy (SEM) system is described, in accordance with
the present disclosure.
[0026] Embodiments of the present disclosure are directed to a
multi-column SEM system including a column assembly. Additional
embodiments of the present disclosure are directed to a method of
fabricating a column assembly. Additional embodiments of the
present disclosure are directed to substrate arrays for use in the
electron-optical columns.
[0027] FIG. 1 illustrates an electron-optical system 100 for
performing SEM imaging of a sample, in accordance with one or more
embodiments of the present disclosure. In one embodiment, the
electron-optical system 100 is a multi-column scanning electron
microscopy (SEM) system. While the present disclosure largely
focuses on an electron-optical arrangement associated with a
multi-column SEM system, it is noted herein that this does not
represent a limitation on the scope of the present disclosure and
is provided merely for illustrative purposes. It is additionally
noted herein that the embodiments described through the present
disclosure may be extended to any electron-optical system
configuration. It is further noted herein that the embodiments
described throughout the present disclosure may be extended to any
optical system configuration for microscopy and/or imaging.
[0028] In one embodiment, the system 100 includes a source assembly
101. In another embodiment, the source assembly 101 includes one or
more illumination sources 102. For example, the one or more
illumination beam sources 102 may include one or more electron beam
sources 102. By way of another example, the one or more
illumination beam sources 102 may include any illumination beam
source known in the art. In another embodiment, the one or more
electron beam sources 102 generate one or more electron beams 103
and direct the one or more electron beams 103 to one or more sets
of source electron-optical elements 104. In another embodiment, the
one or more electron beam sources 102 are coupled to one or more
sets of positioners 106.
[0029] In another embodiment, the system 100 includes a column
assembly 110 including one or more electron-optical columns 130. In
another embodiment, the one or more sets of source electron-optical
elements 104 direct the one or more electron beams 103 through the
column assembly 110.
[0030] In another embodiment, the system 100 includes a stage 140
configured to secure a sample 142. In another embodiment, the
column assembly 110 directs the one or more electron beams 103 to a
surface of the sample 142. In another embodiment, the column
assembly 110 includes one or more electron detectors 150 for
detecting one or more electrons 141 emitted and/or scattered from
the surface of the sample 142 in response to the electron beams
103.
[0031] The one or more electron beam sources 102 may include any
electron beam source known in the art suitable for generating the
one or more electron beams 103. For example, the one or more
electron beam sources 102 may include multiple electron beam
sources 102 for generating multiple electron beams 103, where each
electron beam source 102 generates an electron beam 103. By way of
another example, the one or more electron beam sources 102 may
include a single electron beam source 102 that generates a single
electron beam 103, where the single electron beam 103 is split into
multiple electron beams 103 via one or more illumination source
optical elements (e.g. an aperture array).
[0032] In another embodiment, the electron beam sources 102 include
one or more electron emitters. For example, the one or more
emitters may include, but are not limited to, one or more field
emission guns (FEGs). For instance, the one or more FEGs may
include, but are not limited to, one or more Schottky-type
emitters. It is noted the diameter of the Schottky-type emitters
may be selected to fit within the pitch spacing of the
electron-optical columns 130, while providing a sufficient amount
of clearance for alignment of the electron-optical columns 130.
Additionally, the one or more FEGs may include, but are not limited
to, one or more carbon nanotube (CNT) emitters, one or more
nanostructured carbon film emitters, and/or one or more Muller-type
emitters. By way of another example, the one or more emitters may
include, but are not limited to, one or more photocathode emitters.
By way of another example, the one or more emitters may include,
but are not limited to, one or more silicon emitters.
[0033] In one embodiment, the source assembly 101 includes one or
more sets of positioners 106 to actuate the electron beam sources
102. For example, the source assembly 101 may include multiple sets
of positioners 106, where each set of positioners 106 is configured
to actuate an electron beam source 102. By way of another example,
the source assembly 101 may include a single set of positioners 106
configured to actuate multiple electron beam sources 102 (e.g.
configured to actuate the multiple electron beam sources 102 on a
global scale). In another embodiment, the one or more sets of
positioners 106 are electrically coupled to the one or more
electron beam sources 102. In another embodiment, the one or more
sets of positioners 106 are mechanically coupled to the one or more
electron beam sources 102.
[0034] In another embodiment, each set of positioners 106 includes
one or more positioners 106 configured to translate an electron
beam source 102 along one or more linear directions (e.g.,
x-direction, y-direction and/or z-direction). For example, three
positioners 106 may be configured to translate an electron beam
source 102. For instance, the three positioners may include, but
are not limited to, a first positioner 106 configured to adjust the
electron beam source 102 in an x-direction, a second positioner 106
configured to adjust the electron beam source 102 in a y-direction,
and a third positioner 106 configured to adjust the electron beam
source 102 in a z-direction. It is noted herein that the stacking
order of the positioners within each of the one or more sets of
positioners is provided purely for illustration, and is not to be
understood as limiting for purposes of the present disclosure.
[0035] In one embodiment, the source assembly 101 includes one or
more sets of source electron-optical elements 104. For example, the
source assembly 101 may include a set of source electron-optical
elements 104 for each of the multiple electron beams 103. In
another embodiment, the one or more sets of source electron-optical
elements 104 includes any electron-optical element known in the art
suitable for focusing and/or directing at least a portion of the
electron beams 103 to the column assembly 110. For example, the one
or more sets of source electron-optical elements 104 may include,
but are not limited to, one or more electron-optical lenses (e.g.
one or more magnetic condenser lenses and/or one or more magnetic
focus lenses). By way of another example, the one or more sets of
source electron-optical elements 104 may include one or more
extractors (or extractor electrodes). It is noted herein the one or
more extractors may include any electron beam extractor
configuration known in the art. For instance, the one or more
extractors may include one or more planar extractors. Additionally,
the one or more extractors may include one or more non-planar
extractors. The use of planar and non-planar extractors in electron
beam sources is generally described in U.S. Pat. No. 8,513,619,
issued on Aug. 20, 2013, which is incorporated herein by reference
in its entirety.
[0036] In another embodiment, the source assembly 101 does not
include any source electron-optical elements 104. In this
embodiment, the one or more electron beams 103 are focused and/or
directed by one or more column electron-optical elements 210
positioned within each electron-optical column 130 of the column
assembly 110. For example, the one or more column electron-optical
elements 210 may include, but are not limited to, the one or more
extractors described in detail previously herein. Therefore, the
above description should not be interpreted as a limitation on the
scope of the present disclosure but merely an illustration.
[0037] In one embodiment, the system 100 includes a column assembly
110. In another embodiment, the column assembly 110 includes one or
more substrate array assemblies 120. In another embodiment, the one
or more substrate array assemblies 120 include one or more
substrate arrays 200. In another embodiment, the column assembly
110 includes an electron-optical column 130 for each of the
electron beams 103. In another embodiment, the one or more
electron-optical columns 130 are formed by bonding the one or more
sets of column electron-optical elements 210 to the one or more
substrate arrays 200. In another embodiment, the one or more
electron-optical columns 130 direct at least a portion of the one
or more electron beams 103 to the surface of the sample 142. It is
noted the column assembly 110, the substrate array assemblies 120,
the electron-optical columns 130, the substrate arrays 200, and the
column electron-optical elements 210 are described in detail
further herein.
[0038] In one embodiment, the stage 140 is configured to secure the
sample 142. In another embodiment, the sample stage 140 is an
actuatable stage. For example, the sample stage 140 may include,
but is not limited to, one or more translational stages suitable
for selectably translating the sample 142 along one or more linear
directions (e.g., x-direction, y-direction and/or z-direction). By
way of another example, the sample stage 140 may include, but is
not limited to, one or more rotational stages suitable for
selectively rotating the sample 142 along a rotational direction.
By way of another example, the sample stage 140 may include, but is
not limited to, a rotational stage and a translational stage
suitable for selectably translating the sample along a linear
direction and/or rotating the sample 142 along a rotational
direction.
[0039] The sample 142 includes any sample suitable for
inspection/review with electron-beam microscopy. In one embodiment,
the sample includes a wafer. For example, the sample may include,
but is not limited to, a semiconductor wafer. As used through the
present disclosure, the term "wafer" refers to a substrate formed
of a semiconductor and/or a non-semi-conductor material. For
instance, a semiconductor or semiconductor material may include,
but is not limited to, monocrystalline silicon, gallium arsenide,
and indium phosphide.
[0040] In another embodiment, the sample 142 emits and/or scatters
electrons 141 in response to the electron beams 103. For example,
the electrons 141 may be secondary electrons 141 and/or
backscattered electrons 141.
[0041] In one embodiment, one or more electron detectors 150 are
positioned within the one or more electron-optical columns 130,
such that each electron-optical column 130 includes one or more
electron detectors 150. The one or more electron detectors 150 may
include any type of electron detector assembly known in the art
capable of detecting the electrons 141. For example, the one or
more detectors 150 may include, but are not limited to, one or more
single-piece annular secondary electron detectors. By way of
another example, the one or more detectors 150 may include, but are
not limited to, one or more multi-piece annular secondary electron
detectors. For instance, the one or more multi-piece annular
secondary detectors may include, but are not limited to, one or
more secondary electron quad arrays, one or more secondary electron
octuplet arrays, and the like.
[0042] By way of another example, the electrons 141 may be
collected and imaged using one or more micro-channel plates (MCP).
It is noted herein that the use of MCP-based detectors to detect
electrons is generally described in U.S. Pat. No. 7,335,895, issued
on Feb. 26, 2008, which is incorporated herein by reference in its
entirety. By way of another example, the electrons 141 may be
collected and imaged using one or more PIN or p-n junction
detectors such as a diode or a diode array. By way of another
example, the electrons 141 may be collected and imaged using one or
more avalanche photo diodes (APDs).
[0043] In another embodiment, the system 100 includes one or more
components necessary to inspect a photomask/reticle instead of the
sample 142.
[0044] In another embodiment, the system 100 includes a vacuum
assembly to isolate the source assembly 101 from the column
assembly 110 during operation of the system 100 and/or maintenance
of the column assembly 110. In this regard, the amount of time
required to bring the system 100 back up to operation is reduced.
It is noted herein that the use of a vacuum assembly to generate
differential pumping in a multi-column SEM system is generally
described in U.S. Pat. No. 8,106,358, issued on Jan. 31, 2012,
which is incorporated herein by reference in its entirety.
[0045] In another embodiment, the source assembly 101 includes
ceramic standoffs to electrically and thermally isolate the one or
more electron beam sources 102 from the respective set of
positioners 106 and the surrounding structures of the system
100.
[0046] In another embodiment, the system 100 includes a controller
(not shown). In one embodiment, the controller is communicatively
coupled to one or more of components of system 100. For example,
the controller may be communicatively coupled to the source
assembly 200, components of the source assembly 200, the column
assembly 300, the one or more electron-optical columns 320,
components of the one or more electron-optical columns 320 (e.g.
the one or more column electron-optical elements 340), and/or the
stage 102. In this regard, the controller may direct any of the
components of system 100 to carry out any one or more of the
various functions described previously herein. For example, the
controller may direct the one or more sets of positioners 204
coupled to the one or more electron beam sources 202 to translate
the one or more electron beam sources 202 in one or more of an
x-direction, a y-direction, and/or a z-direction to correct beam
misalignment produced by any of the components of the source
assembly 200, the components of the column assembly 200, the column
assembly 300, the one or more electron-optical columns 320,
components of the one or more electron-optical columns 320 (e.g.
the one or more column electron-optical elements 340), and/or the
stage 102.
[0047] In another embodiment, the controller includes one or more
processors configured to execute program instructions suitable for
causing the one or more processors to execute one or more steps
described in the present disclosure. In one embodiment, the one or
more processors of the controller may be in communication with a
memory medium (e.g., a non-transitory storage medium) containing
program instructions configured to cause the one or more processors
of the controller to carry out various steps described throughout
the present disclosure.
[0048] FIG. 2A illustrates a cross-section view of the column
assembly 110, in accordance with one or more embodiments of the
present disclosure.
[0049] In one embodiment, the column assembly 110 includes one or
more substrate array assemblies 120. For example, the column
assembly 110 may include a first substrate array assembly 120a and
at least a second substrate array assembly 120b. In another
embodiment, the one or more substrate array assemblies 120 each
include one or more substrate arrays 200. For example, a substrate
array assembly 120 may include a substrate array 200a. By way of
another example, substrate array assembly 120 may include a first
substrate array 200a and at least a second substrate array 200b. In
another embodiment, the one or more substrate array assemblies 200
each include one or more holes 201.
[0050] In another embodiment, at least a portion of a top surface
and/or a bottom surface of the one or more substrate arrays 200 is
shielded by a metal layer to prevent errant charging between the
one or more substrate arrays 200, between the one or more substrate
arrays 200 and one or more components bonded to the one or more
substrate arrays 200, and/or between the one or more components
bonded to the one or more substrate arrays 200. In another
embodiment, where a substrate array assembly 120 includes two or
more substrate arrays 200, one or more metal shields 212 are
positioned between the two or more substrate arrays 200. For
example, the one or more metal shields 212 may be configured to
prevent cross talk or errant charging between the one or more
substrate array assemblies 120 and/or components of the one or more
substrate array assemblies 120 in the column assembly 110.
[0051] In another embodiment, the one or more sets of column
electron-optical elements 210 are bonded to the substrate arrays
200 over the one or more holes 201. For example, at least some of
the one or more sets of column electron-optical elements 210 may
include one or more three-dimensional column electron-optical
elements 210. By way of another example, the one or more sets of
column electron-optical elements 210 may include, but are not
limited to, one or more detectors 130, one or more gun multipole
beam deflectors, one or more extractors, one or more magnetic
condenser lenses, one or more gun condenser lenses, one or more
anodes, one or more upper beam deflectors, one or more lower beam
deflectors, one or more dynamic focus lenses, and/or one or more
magnetic focus lenses. It is noted the multipole beam deflectors
are described in detail further herein.
[0052] In another embodiment a first column electron-optical
element 210 is bonded to a top surface or a bottom surface of at
least some of the one or more substrate arrays 200. In another
embodiment, a first and a second column electron-optical element
210 is bonded to a top surface and a bottom surface, respectively,
of at least some of the one or more substrate arrays 200.
[0053] It is noted herein that bonding electron-optical elements to
substrate arrays to form a column assembly is generally described
in U.S. Pat. No. 7,109,486, issued on Sep. 19, 2006, which is
incorporated herein by reference in its entirety.
[0054] In another embodiment, the column assembly 110 includes one
or more electron-optical columns 130. For example, the column
assembly 110 may include a first electron-optical column 130a and
at least a second electron-optical column 130b. By way of another
example, the column assembly 110 may include, but is not limited
to, 2 to 60 electron-optical columns 130. In another embodiment,
the column assembly 110 includes an electron-optical column 130 for
each of the one or more electron beams 103. In another embodiment,
the one or more electron-optical columns 130 direct at least a
portion of the electron beams 103 to the surface of the sample
142.
[0055] In another embodiment, the one or more electron-optical
columns 130 are formed by the one or more sets of column
electron-optical elements 210. For example, an electron-optical
column 130 may be formed by a set of column electron-optical
elements 210 including, but not limited to, a first element 210a, a
second element 210b, a third element 210c, and at least a fourth
element 210d. In another embodiment, an electron-optical column 130
is formed from a set of column electron-optical elements 210 for
each of the one or more electron beams 103.
[0056] In one embodiment, the one or more substrate arrays 200 are
grouped into the first substrate array assembly 120a and the at
least a second substrate array assembly 120b. In another
embodiment, one or more tolerance characteristics of the one or
more substrate array assemblies 200 are inspected prior to grouping
the one or more substrate arrays 200 into the first substrate array
assembly 120 and the at least a second substrate array assembly
120b. For example, the pitch spacing of the one or more substrate
arrays 200 may be inspected for the required tolerances. For
instance, pitch spacing tolerance may include one or more
single-digit micron feature tolerances.
[0057] In one embodiment, the one or more substrate arrays 200 of
the first substrate array assembly 120a are arranged into a first
substrate array stack. In another embodiment, the first substrate
array stack is mounted in a first frame. In another embodiment, the
one or more substrate arrays 200 of the at least a second substrate
array assembly 120b are arranged into at least a second substrate
array stack. In another embodiment, the at least a second substrate
array stack is mounted in at least a second frame. In another
embodiment, the first frame and the at least a second frame are
coupled to form the column assembly 110.
[0058] In another embodiment, one or more alignment errors are
reduced via a least square best fit alignment process when
performing at least one of arranging the one or more substrate
arrays 200 of the first substrate array assembly 120a into the
first substrate array stack, arranging the one or more substrate
arrays 200 of the at least a second substrate array assembly 120b
into the at least a second substrate array stack, and/or coupling
together the first frame and the at least a second frame. For
example, the one or more alignment errors may include, but is not
limited to, an offset distance in an x-direction, an offset
distance in a y-direction, and/or an offset rotation angle.
[0059] In one embodiment, the one or more substrate arrays 200 of
the first substrate array assembly 120a are arranged into a first
bonded substrate array stack. In another embodiment, the one or
more substrate arrays 200 of the at least a second substrate array
assembly 120b are arranged into at least a second bonded substrate
array stack. In another embodiment, the first bonded substrate
array stack and the at least a second bonded substrate array stack
are bonded to form the column assembly 110.
[0060] In another embodiment, one or more alignment errors are
reduced via a least square best fit alignment process when
performing at least one of arranging the one or more substrate
arrays 200 of the first substrate array assembly 120a into the
first bonded substrate array stack, arranging the substrate arrays
200 of the at least a second substrate array assembly 120b into the
at least a second bonded substrate array stack, and/or bonding the
first bonded substrate array stack and the at least a second bonded
substrate array stack. For example, the one or more alignment
errors may include, but is not limited to, an offset distance in an
x-direction, an offset distance in a y-direction, and/or an offset
rotation angle.
[0061] In one embodiment, the one or more substrate arrays 200 of
the first substrate array assembly 120a are arranged into a first
substrate array stack. In another embodiment, the first substrate
array stack is mounted in a frame. In another embodiment, the one
or more substrate arrays 200 of the at least a second substrate
array assembly 120b are arranged into at least a second substrate
array stack. In another embodiment, the at least a second substrate
array stack is mounted in the same frame.
[0062] In another embodiment, one or more alignment errors are
reduced via a least square best fit alignment process when
performing at least one of arranging the one or more substrate
arrays 200 of the first substrate array assembly 120a into the
first substrate array stack or arranging the one or more substrate
arrays 200 of the at least a second substrate array assembly 120b
into the at least a second substrate array stack. For example, the
one or more alignment errors may include, but is not limited to, an
offset distance in an x-direction, an offset distance in a
y-direction, and/or an offset rotation angle.
[0063] FIGS. 2B and 2C illustrate a substrate array 200 of the one
or more substrate arrays, in accordance with one or more
embodiments of the present disclosure.
[0064] In one embodiment, the substrate array 200 includes a
composite layer 202 with one or more holes 201. In another
embodiment, the composite layer 202 is formed from one or more
substrate layers. For example, the composite layer 202 may include,
but is not limited to, a first substrate layer 202a, a second
substrate layer 202b, and at least a third substrate layer 202c. In
another embodiment, the one or more substrate layers are fabricated
from a co-fired ceramic. In another embodiment, the composite layer
200 is formed from the plurality of substrate layers via a
fabrication process. For example, the fabrication process may
include, but is not limited to, pressing together the plurality of
substrate layers, sintering together the plurality of substrate
layers, and/or joining together the plurality of substrate layers
via a co-firing process.
[0065] In another embodiment, the substrate array 200 includes one
or more electrical contact layers 204 coupled to one or more of the
top surface and/or the bottom surface of the composite layer 202.
For example, the substrate array 200 may include a contact layer
204a with one or more electrical contacts coupled to the top
surface of the composite layer 202. By way of another example, the
substrate array 200 may include a contact layer 204b with one or
more electrical contacts coupled to the bottom surface of the
composite layer 202. In another embodiment, the one or more
electrical contacts include one or more ground bonding pads (e.g.
ground contact pads). In another embodiment, the one or more
electrical contacts include one or more signal bonding pads (e.g.
signal contact pads), where the one or more signal bonding pads are
electrically isolated from the one or more ground bonding pads.
[0066] In another embodiment, the one or more contact layers 204
include a metalized coating or a metal plate. In another
embodiment, the one or more contact layers 204 are coupled to the
top surface and/or the bottom surface of the composite layer 202
via a fabrication process. For example, the fabrication may
include, but is not limited to, a pressing process, a sintering
process, an adhesion process (e.g., joining via an epoxy), a
thick-film process, and/or a thin-film process. In another
embodiment, the one or more contact layers 204 are configured to
prevent errant charging and negative beam interaction.
[0067] In another embodiment, the composite layer 202 includes one
or more electrical components 206 embedded within the one or more
substrate layers. In another embodiment, the one or more electrical
components 206 include one or more ground traces 220, one or more
ground vias 222, one or more signal traces 230, and/or one or more
signal vias 232. In another embodiment, the one or more electrical
components 206 are embedded within the plurality of substrate
layers prior to forming the composite layer 202.
[0068] In another embodiment, the one or more ground traces 220 are
electrically coupled to the one or more ground bonding pads in the
one or more contact layers 204 with the one or more ground vias
222. In another embodiment, the one or more signal traces 230 are
electrically coupled to the one or more signal bonding pads in the
one or more contact layers 204 with the one or more signal vias
232.
[0069] It is noted herein that although both the one or more ground
vias 222 and the one or more signal vias 232 are shown within the
same cross-section of the substrate array 200, the one or more
ground vias 222 and the one or more signal vias 232 may be arranged
such that a cross-section of the substrate array 200 would only
include either the one or more ground vias 222 or the one or more
signal vias 232. It is additionally noted herein that although both
the one or more ground bonding pads and the one or more signal
bonding pads in the one or more contact layers 204 are shown in the
same cross-section of the substrate array 200, the one or more
ground bonding pads and the one or more signal bonding pads in the
one or more contact layers 204 may be arranged such that a
cross-section of the substrate array 200 would only include either
the one or more ground bonding pads or the one or more signal
bonding pads. Therefore, the above description should not be
interpreted as a limitation on the scope of the present disclosure
but merely an illustration.
[0070] In another embodiment, the one or more electrical components
206 are electrically coupled to one or more electrical contact pads
208. For example, the one or more ground traces 220 may be
electrically coupled to one or more ground contact pads 208. By way
of another example, the one or more signal traces 230 may be
electrically coupled to one or more signal contact pads 208.
[0071] In another embodiment, the one or more electrical contact
pads 208 are located on a portion of the top surface and/or the
bottom surface of the composite layer 202 not shielding by a
contact layer 204 (e.g. an unshielded portion of the substrate
array 200). It is not herein, however, that a majority of the top
surface and/or the bottom surface of the composite layer 202 is
shielded to prevent errant charging.
[0072] In one embodiment, one or more column electron-optical
elements 210 are bonded to the substrate array 200. For example,
the one or more column electron-optical elements 210 may be bonded
to the top surface and/or the bottom surface of the substrate array
200. By way of another example, the one or more column
electron-optical elements 210 may be bonded to a particular ground
bonding pad and a particular signal bonding pad coupled to the top
surface and/or the bottom surface of the substrate array 200. In
another embodiment, the one or more column electron-optical
elements 210 are bonding to the substrate array 200 via a bonding
process. For example, the bonding process may include, but is not
limited to, a soldering process, a brazing process, or an adhesion
process (e.g. joining via an epoxy).
[0073] In another embodiment, at least some of the one or more
column electron-optical elements 210 are fully fabricated prior to
being bonded to the substrate array 200. In another embodiment, at
least some of the one or more column electron-optical elements 210
are partially fabricated via a first set of fabrication process
prior to being bonded to the substrate array 200, and fully
fabricated via a second set of fabrication processes after being
bonded to the substrate array 200. It is noted the first set of
fabrication processes and the second set of fabrication processes
are described in detail further herein.
[0074] In another embodiment, the one or more column
electron-optical elements 210 are inspected to meet individual
tolerances. For example, the individual tolerances may include one
or more single-digit micron feature tolerances. In another
embodiment, the one or more column electron-optical elements 210
are aligned while being bonded to the substrate array 200 via an
alignment process. For example, the alignment process may include,
but is not limited to, an alignment process to align a plurality of
lithographic target features or an optical overlay alignment
process.
[0075] FIGS. 3A-3C illustrate a partially-fabricated multipole beam
deflector 210, in accordance with one or more embodiments of the
present disclosure.
[0076] In one embodiment, the multipole beam deflector 210 includes
a barrel portion 302 and a disc portion 306. For example, the
barrel portion 302 may be inserted into a hole of a substrate array
200 when the multipole beam deflector 210 is bonded to the
substrate array 200.
[0077] In another embodiment, the multipole beam deflector 210
includes a hole 304 bored through the top of the barrel portion 302
and the bottom of the disc portion 306. For example, the hole 304
may allow an electron beam 103 to pass through the multipole beam
deflector 210. In another embodiment, the hole 304 has one or more
critical tolerances. For example, the one or more critical
tolerances may include, but are not limited to, a bore size and/or
a bore shape.
[0078] In another embodiment, the multipole beam deflector 210
includes one or more slots 308. For example, the one or more slots
308 may be partially cut into the multipole beam deflector 210,
such that the one or more slots 308 cut through the barrel portion
302 and the disc portion 306 of the multipole beam deflector 210
without extending to the edge of the disc portion 306. It is noted
herein that if the one or more slots 308 extended to the edge of
the disc portion 306, the multipole beam deflector 210 would be
segmented into multiple individual beam deflector poles.
[0079] In another embodiment, the multipole beam deflector 210
includes a raised region 310 on an outer area of the disc portion
306. For example, the raised region 310 may offset an inner area of
the disc portion 306 from the top surface or the bottom surface of
the substrate array 200 at a distance equal to the height of the
raised region 310. In another embodiment, the multipole beam
deflector 310 includes one or more grooves 312 in the raised region
310. For example, the one or more grooves 312 in the raised region
310 may be work areas for one or more post-bonding fabrication
processes, to ensure the one or more post-bonding fabrication
processes do not damage (or otherwise interfere with the operation
of) the substrate array 200.
[0080] FIG. 3D illustrates a set of fully-fabricated multipole beam
deflectors bonded to a substrate array 200, in accordance with one
or more embodiments of the present disclosure.
[0081] In one embodiment, one or more partially-fabricated
multipole beam deflectors 210 are bonded to the contact layers 304
of the substrate array 200. In another embodiment, the one or more
slots 308 are extended to the edge of the one or more
partially-fabricated multipole beam deflectors 210 at the one or
more grooves 312 via a cutting process, where the cutting process
segments the one or more partially-fabricated multipole beam
deflectors 210 into individual beam deflector poles 210a, thus
fully-fabricating the one or more multipole beam deflectors 210.
For example, the one or more partially-fabricated multipole beam
deflectors 210 may include, but are not limited to, 2-12 slots 308,
which segment the partially-fabricated multipole beam deflectors
210 into 4-24 individual beam deflector poles (e.g. resulting in a
quadrupole beam deflector, an octupole beam deflector, and the
like) when extending to the edge of the multipole beam deflectors
210 to fully fabricate the one or more multipole beam deflectors
210.
[0082] Advantages of the embodiments of the present disclosure
include fabricating and aligning multi-column SEM systems with
decreased pitch spacing and tighter tolerances. Advantages of the
present disclosure also include forming better-matching substrate
array assemblies by inspecting substrate arrays and sorting the
substrate arrays based on inspection results. Advantages of the
present disclosure also include improving the yield of fabricated
electron-optical elements by partially fabricating electron-optical
elements via a first set of fabrication processes, inspecting the
partially-fabricated electron-optical elements, sorting the
partially-fabricated electron-optical elements to matched sets
based on inspection results, aligning the matched sets of
partially-fabricated electron-optical elements, bonding the
partially-fabricated electron-optical elements to a substrate
array, and fully fabricating the bonded electron-optical elements
via a second set of fabrication processes. Advantages of the
present disclosure also include preventing charging and reducing
cross talk between multiple electron-optical column beam
signals.
[0083] FIG. 4 illustrates a process flow diagram depicting a method
400 to fabricate a column assembly 110 for a multi-column SEM
system 100. The method may also include any other step(s) that can
be performed by the output acquisition subsystem and/or computer
subsystem(s) or system(s) described herein.
[0084] In step 402, one or more substrate arrays 200 are formed. In
one embodiment, forming the one or more substrate arrays 200
includes embedding one or more electrical components 206 within one
or more substrate layers 202, where at least some of the one or
more the substrate layers 202 are fabricated from a co-fired
ceramic. In another embodiment, the one or more electrical
components 206 include one or more ground traces 220, one or more
signal traces 230, one or more ground vias 222, and/or one or more
signal vias 232.
[0085] In another embodiment, forming the one or more substrate
arrays 202 includes forming a composite substrate 204 from the
plurality of substrate layers. For example, forming a composite
substrate from the substrate layers may include, but is not limited
to, pressing together the substrate layers, sintering together the
substrate layers, or joining together the substrate layers via a
co-firing process. In another embodiment, forming the one or more
substrate arrays 200 includes boring a plurality of holes 201 in
the composite substrate 202.
[0086] In another embodiment, forming the one or more substrate
arrays 200 includes coupling one or more contact layers 204 to at
least one of the top surface or the bottom surface of the composite
substrate 202, where the one or more contact layers 204 include a
metalized coating and/or a metal plate. For example, coupling the
one or more contact layers 204 may include a pressing process, a
sintering process, an adhesion process, a thick-film process,
and/or a thin-film process. For instance, the adhesion process may
be, but is not limited to, joining with an epoxy. In another
embodiment, the one or more contact layers 204 include one or more
ground bonding pads. For example, the one or more ground traces 220
may be electrically coupled to the one or more ground bonding pads
with the one or more ground vias 222. In another embodiment, the
contact layers 204 include one or more signal bonding pads, where
the one or more signal bonding pads are electrically isolated from
the one or more ground bonding pads. For example, the one or more
signal traces 230 may be electrically coupled to the one or more
signal bonding pads with the one or more signal vias 232.
[0087] In another embodiment, forming the one or more substrate
arrays 200 includes positioning each of the one or more column
electron-optical elements 210 over a hole 201 in the composite
substrate 202. In another embodiment, forming the one or more
substrate arrays 200 includes bonding one or more column
electron-optical elements 210 to a particular ground bonding pad of
the one or more ground bonding pads and a particular signal bonding
pad of the one or more signal bonding pads coupled to at least one
of the top surface or the bottom surface of the composite substrate
202. For example, bonding each of the one or more column
electron-optical elements 210 to the particular ground bonding pad
and the particular signal bonding pad may include, but is not
limited to, a soldering process, a brazing process, or an adhesion
process (e.g., joining via an epoxy). By way of another example,
bonding each of the one or more column electron-optical elements
210 elements to the particular ground bonding pad and the
particular signal bonding pad may include an alignment process such
as, but not limited to, an alignment process to align a plurality
of lithographic target features or an optical overlay alignment
process.
[0088] In another embodiment, at least some of the column
electron-optical elements 210 are fully fabricated prior to being
bonded to the particular ground bonding pad and a particular signal
bonding pad. In another embodiment, at least some of the column
electron-optical elements 210 (e.g. multipole beam deflectors 210)
are partially fabricated via a first set of fabrication processes
prior to bonding the at least some of the column electron-optical
elements 210 to a particular ground bonding pad and a particular
signal bonding pad, and are fully fabricated via a second set of
fabrication processes after bonding the at least some of the column
electron-optical elements 210 to the particular ground bonding pad
and the particular signal bonding pad.
[0089] For example, the first set of fabrication processes may
include boring a hole 304 based on one or more critical tolerances
(e.g. a bore size and/or a bore shape) in a column electron-optical
element 210, and cutting one or more slots 308 in the column
electron-optical element 210. For instance, the one or more slots
308 may include a first slot 308 and at least a second slot 308.
Additionally, the first slot 308 and the at least a second slot 308
may pass through a portion of the hole 304. Further, the first slot
308 and the at least a second slot 308 may not extend to the edge
of the column electron-optical element 210. By way of another
example, the second set of fabrication processes may include
cutting the one or more slots 308 to extend to the edge of the
column electron-optical element 210, such that the column
electron-optical element 210 is segmented into one or more beam
deflector poles (e.g. 2-12 slots segment the column
electron-optical element 210 into 4-24 beam deflector poles).
[0090] In step 404, the formed substrate arrays 200 are sorted into
a first substrate array assembly 120a and at least a second
substrate array assembly 120b. In one embodiment, the formed
substrate arrays 200 are inspected prior to being sorted into the
first substrate array assembly 120a and the at least a second
substrate array assembly 120b. In another embodiment, the sorting
of the formed substrate arrays 200 is based on inspection
results.
[0091] In step 406, a column assembly 110 is formed from the first
substrate array assembly 120a and the at least a second substrate
array assembly 120b. In one embodiment, the column assembly 110
includes one or more electron-optical columns 130 formed from the
one or more column electron-optical elements 210 bonded to the one
or more substrate arrays 200 of the first substrate array assembly
120a and the at least a second substrate array assembly 120b, as
previously described herein.
[0092] In one embodiment, forming the column assembly 110 includes
arranging the first substrate array assembly 120a in a first
substrate array stack. In another embodiment, forming the column
assembly 110 includes mounting the first substrate array stack in a
first frame. In another embodiment, forming the column assembly 110
includes arranging the at least a second substrate array assembly
120b in at least a second substrate array stack. In another
embodiment, forming the column assembly 100 includes mounting the
at least a second substrate array assembly in at least a second
frame. In another embodiment, forming the column assembly 110
includes coupling the first frame and the at least a second frame.
In another embodiment, one or more alignment errors are reduced via
a least square best fit alignment process when performing at least
one of arranging the first substrate array assembly 120a, arranging
the at least a second substrate array assembly 120b, or coupling
the first frame and the at least a second frame. For example, the
one or more alignment errors may include, but are not limited to,
an offset distance in an x-direction, an offset distance in a
y-direction, and/or an offset rotation angle,
[0093] In one embodiment, forming the column assembly 110 includes
arranging the first substrate array assembly 120a in a first bonded
substrate array stack. In another embodiment, forming the column
assembly 110 includes arranging the at least a second substrate
array assembly 120b in at least a second bonded substrate array
stack. In another embodiment, forming the column assembly 110
includes bonding the first bonded substrate array stack and the at
least a second bonded substrate array stack. In another embodiment,
one or more alignment errors are reduced via a least square best
fit alignment process when performing at least one of arranging the
first substrate array assembly 120a, arranging the at least a
second substrate array assembly 120b, or bonding the first bonded
substrate array stack and the at least a second bonded substrate
array stack. For example, the one or more alignment errors may
include, but are not limited to, an offset distance in an
x-direction, an offset distance in a y-direction, and/or an offset
rotation angle.
[0094] In one embodiment, forming the column assembly 110 includes
arranging the first substrate array assembly 120a in a first
substrate array stack. In another embodiment, forming the column
assembly 110 includes mounting the first substrate array stack in a
frame. In another embodiment, forming the column assembly 110
includes arranging the at least a second substrate array assembly
120b in at least a second substrate array stack. In another
embodiment, forming the column assembly 100 includes mounting the
at least a second substrate array assembly in the same frame. In
another embodiment, one or more alignment errors are reduced via a
least square best fit alignment process when performing at least
one of arranging the first substrate array assembly 120a or
arranging the at least a second substrate array assembly 120b. For
example, the one or more alignment errors may include, but are not
limited to, an offset distance in an x-direction, an offset
distance in a y-direction, and/or an offset rotation angle,
[0095] One skilled in the art will recognize that the herein
described components (e.g., operations), devices, objects, and the
discussion accompanying them are used as examples for the sake of
conceptual clarity and that various configuration modifications are
contemplated. Consequently, as used herein, the specific exemplars
set forth and the accompanying discussion are intended to be
representative of their more general classes. In general, use of
any specific exemplar is intended to be representative of its
class, and the non-inclusion of specific components (e.g.,
operations), devices, and objects should not be taken limiting.
[0096] With respect to the use of substantially any plural and/or
singular terms herein, those having skill in the art can translate
from the plural to the singular and/or from the singular to the
plural as is appropriate to the context and/or application. The
various singular/plural permutations are not expressly set forth
herein for sake of clarity.
[0097] The herein described subject matter sometimes illustrates
different components contained within, or connected with, different
other components. It is to be understood that such depicted
architectures are merely exemplary, and that in fact many other
architectures may be implemented which achieve the same
functionality. In a conceptual sense, any arrangement of components
to achieve the same functionality is effectively "associated" such
that the desired functionality is achieved. Hence, any two
components herein combined to achieve a particular functionality
can be seen as "associated with" each other such that the desired
functionality is achieved, irrespective of architectures or
intermedial components. Likewise, any two components so associated
can also be viewed as being "operably connected", or "operably
coupled," to each other to achieve the desired functionality, and
any two components capable of being so associated can also be
viewed as being "operably couplable," to each other to achieve the
desired functionality. Specific examples of operably couplable
include but are not limited to physically mateable and/or
physically interacting components, and/or wirelessly interactable,
and/or wirelessly interacting components, and/or logically
interacting, and/or logically interactable components.
[0098] In some instances, one or more components may be referred to
herein as "configured to," "configurable to," "operable/operative
to," "adapted/adaptable," "able to," "conformable/conformed to,"
etc. Those skilled in the art will recognize that such terms (e.g.,
"configured to") can generally encompass active-state components
and/or inactive-state components and/or standby-state components,
unless context requires otherwise.
[0099] While particular aspects of the present subject matter
described herein have been shown and described, it will be apparent
to those skilled in the art that, based upon the teachings herein,
changes and modifications may be made without departing from the
subject matter described herein and its broader aspects and,
therefore, the appended claims are to encompass within their scope
all such changes and modifications as are within the true spirit
and scope of the subject matter described herein. It will be
understood by those within the art that, in general, terms used
herein, and especially in the appended claims (e.g., bodies of the
appended claims) are generally intended as "open" terms (e.g., the
term "including" should be interpreted as "including but not
limited to," the term "having" should be interpreted as "having at
least," the term "includes" should be interpreted as "includes but
is not limited to," etc.). It will be further understood by those
within the art that if a specific number of an introduced claim
recitation is intended, such an intent will be explicitly recited
in the claim, and in the absence of such recitation no such intent
is present. For example, as an aid to understanding, the following
appended claims may contain usage of the introductory phrases "at
least one" and "one or more" to introduce claim recitations.
However, the use of such phrases should not be construed to imply
that the introduction of a claim recitation by the indefinite
articles "a" or "an" limits any particular claim containing such
introduced claim recitation to claims containing only one such
recitation, even when the same claim includes the introductory
phrases "one or more" or "at least one" and indefinite articles
such as "a" or "an" (e.g., "a" and/or "an" should typically be
interpreted to mean "at least one" or "one or more"); the same
holds true for the use of definite articles used to introduce claim
recitations. In addition, even if a specific number of an
introduced claim recitation is explicitly recited, those skilled in
the art will recognize that such recitation should typically be
interpreted to mean at least the recited number (e.g., the bare
recitation of "two recitations," without other modifiers, typically
means at least two recitations, or two or more recitations).
Furthermore, in those instances where a convention analogous to "at
least one of A, B, and C, etc." is used, in general such a
construction is intended in the sense one having skill in the art
would understand the convention (e.g., "a system having at least
one of A, B, and C" would include but not be limited to systems
that have A alone, B alone, C alone, A and B together, A and C
together, B and C together, and/or A, B, and C together, etc.). In
those instances where a convention analogous to "at least one of A,
B, or C, etc." is used, in general such a construction is intended
in the sense one having skill in the art would understand the
convention (e.g., "a system having at least one of A, B, or C"
would include but not be limited to systems that have A alone, B
alone, C alone, A and B together, A and C together, B and C
together, and/or A, B, and C together, etc.). It will be further
understood by those within the art that typically a disjunctive
word and/or phrase presenting two or more alternative terms,
whether in the description, claims, or drawings, should be
understood to contemplate the possibilities of including one of the
terms, either of the terms, or both terms unless context dictates
otherwise. For example, the phrase "A or B" will be typically
understood to include the possibilities of "A" or "B" or "A and
B.
[0100] With respect to the appended claims, those skilled in the
art will appreciate that recited operations therein may generally
be performed in any order. Also, although various operational flows
are presented in a sequence(s), it should be understood that the
various operations may be performed in other orders than those
which are illustrated, or may be performed concurrently. Examples
of such alternate orderings may include overlapping, interleaved,
interrupted, reordered, incremental, preparatory, supplemental,
simultaneous, reverse, or other variant orderings, unless context
dictates otherwise. Furthermore, terms like "responsive to,"
"related to," or other past-tense adjectives are generally not
intended to exclude such variants, unless context dictates
otherwise.
[0101] It is believed that the present disclosure and many of its
attendant advantages will be understood by the foregoing
description, and it will be apparent that various changes may be
made in the form, construction and arrangement of the components
without departing from the disclosed subject matter or without
sacrificing all of its material advantages. The form described is
merely explanatory, and it is the intention of the following claims
to encompass and include such changes. Accordingly, the scope of
the invention should be limited only by the claims appended
hereto.
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