Multi-column scanning electron microscope system

Abstract

A multi-column scanning electron microscope (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 that includes two or more illumination sources configured to generate two or more electron beams and two sets or more of multiple positioners configured to adjust a position of a particular illumination source of the two or more illumination sources in multiple directions. The system also includes a stage configured to hold a sample, where the column assembly directs at least a portion of the two or more electron beams onto a portion of the sample.

Description

[0001] Related Application Data

[0002] This application is a divisional application of the application for patent application serial number 201880015469.9, filed February 2, 2018, entitled “Multi-Column Scanning Electron Microscope System.”

[0003] Cross Reference To Related Applications

[0004] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62 / 454,715, entitled “METHOD OF COLUMN QUADRUPOLE OR OCTUPOLE ALIGNMENT, BONDING AND POST-MACHINING,” filed February 3, 2017, naming Robert Haynes, Aron Welk, and Mehran Nasser Ghodsi as inventors, and U.S. Provisional Patent Application No. 62 / 455,955, entitled “COLUMN MANUFACTURING AND ASSEMBLY,” filed February 7, 2017, naming Aron Welk, Robert Haynes, Tomas Plettner, and John Gerling as inventors, each of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0005] The present disclosure relates generally to wafer and photomask / reticle inspection and review, and more particularly, the present disclosure relates to a column assembly for a multi-column scanning electron microscope system used during wafer and photomask / reticle inspection and review. BACKGROUND

[0006] Manufacturing of semiconductor devices, such as logic and memory devices, typically includes processing a semiconductor device using a large number of semiconductor manufacturing processes to form various features and multiple levels of the semiconductor device. Some manufacturing processes utilize a photomask / reticle to print features on the semiconductor device, such as a wafer. As semiconductor device sizes become increasingly smaller, it becomes critically important to develop enhanced inspection and review devices and procedures to improve resolution, speed, and throughput of wafer and photomask / reticle inspection processes.

[0007] One inspection technique includes electron beam based inspection such as scanning electron microscopy (SEM). In some examples, scanning electron microscopy is performed by splitting a single electron beam into a number of electron beams and individually tuning and scanning the number of electron beams with a single electron optical column (e.g., a multi-beam SEM system). However, splitting the electron beam into N lower current beams typically reduces the resolution of the multi-beam SEM system because the N electron beams are tuned globally and cannot be optimized for individual images. Additionally, splitting the electron beam into N electron beams results in a need for more scanning and averaging to obtain an image, which reduces the speed and throughput of the multi-beam SEM system. These issues increase as the electron optical column array size increases.

[0008] In other examples, scanning electron microscopy is performed via a SEM system that includes an increased number of electron optical columns (e.g., a multi-column SEM system). Typically, these electron optical columns are individual stacks of metal, ceramic rings, and electromagnets. These individual stacks are too large to be placed together at an ideal pitch that optimizes the scanning speed of a wafer, photomask / reticle, and cannot be miniaturized to allow a large number of electron optical columns to be packed in the available area, resulting in a limited number of stacks (e.g., 4 stacks) in the multi-column SEM system. Additionally, having individual stacks results in issues of electron optical column matching, cross-talk between columns, and false charging.

[0009] Furthermore, as the electron optical columns become smaller, there are size limitations in manufacturing individual components such as the multipole electron beam deflector (e.g., a quadrupole or octupole electron beam deflector) elements of the electron optical columns. One method of manufacturing the multipole electron beam deflector includes fabricating an array of critical tolerance lens holes and radial slots in a metal via that segments and electrically isolates the poles of the multipole electron beam deflector. As the electron optical column size decreases, the multipole electron beam deflector becomes more susceptible to manufacturing errors that can render the entire element unusable, which subsequently reduces the yield of the manufacturing process. Another method of manufacturing the multipole electron beam deflector includes pre-fabricating individual poles of the multipole electron beam deflector and then joining the individual poles together (either in pairs or via an alignment jig). This method is limited in terms of manufacturing time and is limited to selected manufacturing methods due to the close proximity of the individual poles. Additionally, this method is susceptible to errors in maintaining the manufacturing tolerances because the tolerances are affected by the relative placement errors of the individual poles of the multipole electron beam deflector. Furthermore, maintaining the desired critical tolerances in aligning and joining the individual poles of the multipole electron beam deflector will require precise, microscopic tooling. This tooling adds a significant amount of thermal mass during the joining process and the space required for the tooling limits the subsequent electron optical column pitch.

[0010] Therefore, it would be advantageous to provide a system that overcomes the above disadvantages. SUMMARY

[0011] According to one or more embodiments of the present disclosure, a substrate array is disclosed. In one embodiment, the substrate array includes a composite substrate formed of 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 bond 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 bond 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, each of the plurality of column electron optical elements is positioned over the plurality of holes in the composite substrate. In another embodiment, each of the plurality of column electron optical elements is bonded to a particular ground bond pad and a particular signal bond pad coupled to at least one of the top surface or the bottom surface of the composite substrate.

[0012] According to one or more embodiments of the present disclosure, a multi-column scanning electron microscope (SEM) system is disclosed. 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 of 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 bond 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 bond 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 is bonded to a particular ground bond pad and a particular signal bond pad coupled to at least one of the top surface or the bottom surface of the composite substrate.

[0013] 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, the plurality of positioners of each set 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.

[0014] In accordance with one or more embodiments of the present disclosure, a method is disclosed. In one embodiment, the method can include, but is not limited to, forming a plurality of substrate arrays. In another embodiment, forming a substrate array of the plurality of substrate arrays can 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 can 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 can include, but is not limited to, drilling a plurality of holes in the composite substrate. In another embodiment, forming the substrate array of the plurality of substrate arrays can include, but is not limited to, coupling at least one ground bond 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 can include, but is not limited to, coupling at least one signal bond 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 can include, but is not limited to, bonding a plurality of column electron optical elements to a particular ground bond pad and a particular signal bond 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 is positioned over the plurality of holes in the composite substrate.

[0015] In another embodiment, the method can include, but is not limited to, classifying the plurality of substrate arrays into a first substrate array assembly and at least a second substrate array assembly. In another embodiment, the method can 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.

[0016] 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 application as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the subject matter. The description and drawings together serve to explain the principles of the application.BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0017] The numerous advantages of the application can be better understood by reference to the drawings, in which:

[0018] Figure 1 is a simplified schematic diagram of a multi-column scanning electron microscope (SEM) system equipped with a column assembly in accordance with one or more embodiments of the application.

[0019] Figure 2A is a cross-sectional view of a column assembly of a multi-column SEM system in accordance with one or more embodiments of the application.

[0020] Figure 2B is a substrate array of a column assembly in accordance with one or more embodiments of the application.

[0021] Figure 2C is a cross-sectional view of a substrate array of a column assembly in accordance with one or more embodiments of the application.

[0022] Figure 3A is an isometric view of a partially fabricated multipole electron beam deflector in accordance with one or more embodiments of the application.

[0023] Figure 3B is a bottom view of a partially fabricated multipole electron beam deflector in accordance with one or more embodiments of the application.

[0024] Figure 3C is a cross-sectional view of a partially fabricated multipole electron beam deflector in accordance with one or more embodiments of the application.

[0025] Figure 3D is a substrate array equipped with a fully fabricated multipole electron beam deflector in accordance with one or more embodiments of the application.

[0026] Figure 4 is a method for fabricating a column assembly of a multi-column SEM system in accordance with one or more embodiments of the application. DETAILED DESCRIPTION

[0027] Reference will now be made in detail to the disclosure, which is illustrated in the accompanying drawings.

[0028] Referring generally to Figures 1 to 4 , a multi-column scanning electron microscope (SEM) system in accordance with the present application is described.

[0029] Embodiments of the present application relate to a multi-column SEM system including a column assembly. Additional embodiments of the present application relate to a method of fabricating a column assembly. Additional embodiments of the present application relate to a substrate array for use in an electron-optical column.

[0030] A multi-column scanning electron microscopy system is described in detail in the assignee's case entitled "MULTI-COLUMN SCANNING ELECTRON MICROSCOPY SYSTEM," by inventors Robert Haines et al., attorney docket number KLA P5068, and U.S. Patent Application No. 15 / 616,749, which is incorporated herein by reference in its entirety.

[0031] Figure 1 An electron optical system 100 for performing SEM imaging of a sample in accordance with one or more embodiments of the present disclosure is illustrated. In one embodiment, the electron optical system 100 is a multi-column scanning electron microscopy (SEM) system. Although the present disclosure is primarily focused on electron optical arrangements associated with multi-column SEM systems, it should be noted herein that this does not represent a limitation on the scope of the present disclosure, but is merely illustrative. Additionally, it should be noted herein that the embodiments described by the present disclosure are extendable to any electron optical system configuration. It should be further noted herein that the embodiments described in the present disclosure are extendable to any optical system configuration for microscopy and / or imaging.

[0032] In one embodiment, the system 100 includes a source assembly 101. In another embodiment, the source assembly 101 includes one or more illumination beam sources 102. For example, the one or more illumination beam sources 102 can include one or more electron beam sources 102. By way of another example, the one or more illumination beam sources 102 can 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.

[0033] In another embodiment, the system 100 includes a column assembly 110 having 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.

[0034] 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.

[0035] The one or more electron beam sources 102 can 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 can include a plurality of electron beam sources 102 for generating a plurality of electron beams 103, with each electron beam source 102 generating an electron beam 103. By way of another example, the one or more electron beam sources 102 can include a single electron beam source 102 generating a single electron beam 103, with the single electron beam 103 being split into a plurality of electron beams 103 via one or more illumination source optical assemblies, such as an aperture array.

[0036] In another embodiment, the electron beam source 102 includes one or more electron emitters. For example, the one or more emitters can include, but are not limited to, one or more field emission guns (FEGs). For example, the one or more FEGs can include, but are not limited to, one or more Schottky-type emitters. It should be noted that the diameter of the Schottky-type emitters can be selected to fit within the pitch spacing of the electron optical column 130 while providing a sufficient amount of clearance to align the electron optical column 130. Additionally, the one or more FEGs can 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 can include, but are not limited to, one or more photocathode emitters. By way of another example, the one or more emitters can include, but are not limited to, one or more silicon emitters.

[0037] In one embodiment, the source assembly 101 includes one or more sets of positioners 106 for actuating the electron beam source 102. For example, the source assembly 101 can include a plurality of sets of positioners 106, with each set of positioners 106 configured to actuate the electron beam source 102. By way of another example, the source assembly 101 can include a single set of positioners 106 configured to actuate a plurality of electron beam sources 102, such as configured to actuate a plurality of electron beam sources 102 across a global range. 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.

[0038] In another embodiment, each set of positioners 106 includes one or more positioners 106 configured to translate the electron beam source 102 along one or more linear directions, such as the x-direction, the y-direction, and / or the z-direction. For example, three positioners 106 can be configured to translate the electron beam source 102. For example, the three positioners can include, but are not limited to, a first positioner 106 configured to adjust the electron beam source 102 in the x-direction, a second positioner 106 configured to adjust the electron beam source 102 in the y-direction, and a third positioner 106 configured to adjust the electron beam source 102 in the z-direction. It is noted herein that the stacking order of the positioners within each of the one or more sets of positioners is for illustration only and should not be construed as limiting to the present disclosure.

[0039] In one embodiment, the source assembly 101 includes one or more sets of source electron optical elements 104. For example, the source assembly 101 can include one set of source electron optical elements 104 for each of the plurality of electron beams 103. In another embodiment, the one or more sets of source electron optical elements 104 include 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 can include, but are not limited to, one or more electron optical lenses, such as one or more magnetic condenser lenses and / or one or more magnetic focusing lenses. By way of another example, the one or more sets of source electron optical elements 104 can include one or more extractors (or extractor electrodes). It is noted herein that the one or more extractors can include any electron beam extractor configuration known in the art. For example, the one or more extractors can include one or more planar extractors. Additionally, the one or more extractors can include one or more non-planar extractors. The use of planar and non-planar extractors in an electron beam source is generally described in U.S. Patent No. 8,513,619, issued August 20, 2013, which is incorporated herein by reference in its entirety.

[0040] 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 beam column 130 of the column assembly 110. For example, the one or more column electron optical elements 210 can include, but are not limited to, one or more extractors previously described in detail herein. Accordingly, the above description should not be construed as limiting to the scope of the present disclosure, but merely as an illustration.

[0041] The source assembly 101 is further described in detail in KLA P5068, previously incorporated herein in its entirety.

[0042] 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 one or more sets of column electron-optical elements 210 to 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 a surface of the sample 142. It is noted that the column assembly 110, the substrate array assembly 120, the electron-optical column 130, the substrate array 200, and the column electron-optical element 210 will be described in further detail herein.

[0043] In one embodiment, the sample 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 can include, but is not limited to, one or more translation stages suitable for selectively translating the sample 142 along one or more linear directions, such as an x-direction, a y-direction, and / or a z-direction. By way of another example, the sample stage 140 can include, but is not limited to, one or more rotation stages suitable for selectively rotating the sample 142 along a rotational direction. By way of another example, the sample stage 140 can include, but is not limited to, a rotation stage and a translation stage suitable for selectively translating the sample along a linear direction and / or rotating the sample 142 along a rotational direction.

[0044] The sample 142 includes any sample suitable for inspection / re-inspection using an electron beam microscope. In one embodiment, the sample includes a wafer. For example, the sample can include, but is not limited to, a semiconductor wafer. As used by the present disclosure, the term "wafer" refers to a substrate formed of semiconductor and / or non-semiconductor material. For example, the semiconductor or semiconductor material can include, but is not limited to, monocrystalline silicon, gallium arsenide, and indium phosphide.

[0045] In another embodiment, the sample 142 emits and / or scatters electrons 141 in response to the electron beam 103. For example, the electrons 141 can be secondary electrons 141 and / or backscattered electrons 141.

[0046] In one embodiment, one or more electron detectors 150 are positioned within 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 can include any type of electron detector assembly known in the art capable of detecting electrons 141. For example, the one or more detectors 150 can include, but are not limited to, one or more single-piece annular secondary electron detectors. By way of further example, the one or more detectors 150 can include, but are not limited to, one or more multi-piece annular secondary electron detectors. For example, the one or more multi-piece annular secondary electron detectors can include, but are not limited to, one or more secondary electron quad arrays, one or more secondary electron octet arrays, and the like.

[0047] By way of further example, one or more microchannel plates (MCPs) can be used to collect and image electrons 141. It is noted herein that the use of MCP-based detectors to detect electrons is generally described in U.S. Patent No. 7,335,895, issued February 26, 2008, which is incorporated herein by reference in its entirety. By way of further example, one or more PIN or p-n junction detectors, such as diodes or diode arrays, can be used to collect and image electrons 141. By way of further example, one or more avalanche photodiodes (APDs) can be used to collect and image electrons 141.

[0048] In another embodiment, system 100 includes one or more components required to inspect a photomask rather than a sample 142.

[0049] In another embodiment, system 100 includes a vacuum assembly to isolate source assembly 101 from column assembly 110 during operation of system 100 and / or maintenance of column assembly 110. In this regard, the amount of time required to return system 100 to operation is reduced. It is noted herein that the use of a vacuum assembly to create differential pumping in a multi-column SEM system is generally described in U.S. Patent No. 8,106,358, issued January 31, 2012, which is incorporated herein by reference in its entirety.

[0050] In another embodiment, source assembly 101 includes a ceramic pedestal to electrically and thermally isolate one or more electron beam sources 102 from a set of corresponding positioners 106 and surrounding structures of system 100.

[0051] In another embodiment, system 100 includes a controller (not shown). In one embodiment, the controller is communicatively coupled to one or more components of system 100. For example, the controller may be communicatively coupled to source assembly 101, components of source assembly 101, column assembly 110, one or more electro-optical columns 130, components of one or more electro-optical columns 130 (e.g., one or more column electro-optical elements 210), and / or stage 140. In this respect, the controller may direct any component of system 100 to perform any one or more of the various functions described herein. For example, the controller may instruct one or more sets of positioners 106 coupled to one or more electron beam sources 102 to translate one or more electron beam sources 102 in one or more of the x, y and / or z directions to correct electron beam misalignment caused by any component of the source assembly 101, the pillar assembly 110, the pillar assembly 110, one or more electron optical pillars 130, the components of one or more electron optical pillars 130 (e.g., one or more pillar electron optical elements 210), and / or any component of the stage 140.

[0052] In another embodiment, the controller includes one or more processors configured to execute program instructions suitable for causing the one or more processors to perform one or more steps described in the present invention. In one embodiment, one or more processors of the controller may communicate with memory media (e.g., non-transitory storage media) containing program instructions configured to cause the one or more processors of the controller to implement the various steps described in the present invention.

[0053] Figure 2A A cross-sectional view of the column assembly 110 according to one or more embodiments of the present invention is shown.

[0054] In one embodiment, the pillar assembly 110 includes one or more substrate array assemblies 120. For example, the pillar assembly 110 may include a first substrate array assembly 120a and at least one second substrate array assembly 120b. In another embodiment, each of the one or more substrate array assemblies 120 includes one or more substrate arrays 200. For example, the substrate array assembly 120 may include a substrate array 200a. By another example, the substrate array assembly 120 may include a first substrate array 200a and at least one second substrate array 200b. In another embodiment, each of the one or more substrate array assemblies 200 includes one or more vias 201.

[0055] In another embodiment, at least a portion of the top and / or bottom surface of the one or more substrate array 200 is shielded by a metal layer to prevent false charging between the one or more substrate array 200, between the one or more substrate array 200 and one or more components bonded to the one or more substrate array 200, and / or between one or more components bonded to the one or more substrate array 200. In another embodiment, when the 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 can be configured to prevent cross-talk or false charging between the one or more substrate array assembly 120 and / or components of the one or more substrate array assembly 120 in the column assembly 110.

[0056] In another embodiment, one or more sets of column electron optical elements 210 are bonded to the substrate array 200 above the one or more apertures 201. For example, at least one of the one or more sets of column electron optical elements 210 can 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 can include, but are not limited to, one or more detectors 150, one or more gun multipole electron 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 electron beam deflectors, one or more lower electron beam deflectors, one or more dynamic focusing lenses, and / or one or more magnetic focusing lenses. It should be noted that multipole electron beam deflectors are described in further detail herein.

[0057] In another embodiment, a first column electron optical element 210 is bonded to the top or bottom surface of at least some of the one or more substrate array 200. In another embodiment, a first and second column electron optical element 210 are bonded to the top and bottom surface, respectively, of at least some of the one or more substrate array 200.

[0058] It should be noted herein that U.S. Patent No. 7,109,486, issued September 19, 2006, generally describes bonding electron optical elements to a substrate array to form a column assembly, which is incorporated herein by reference in its entirety.

[0059] In another embodiment, the column assembly 110 includes one or more electron optical columns 130. For example, the column assembly 110 can 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 can 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 beam 103 to the surface of the sample 142.

[0060] In another embodiment, the one or more electron-optical columns 130 are formed by one or more sets of column electron-optical elements 210. For example, the electron-optical column 130 can 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 one fourth element 210d. In another embodiment, the electron-optical column 130 is formed by a set of column electron-optical elements 210 for each of the one or more electron beams 103.

[0061] The sequence and arrangement of the one or more sets of column electron-optical elements 210 forming the one or more electron-optical columns 130 are further described in detail in Attorney Docket No. KLA P5068, previously incorporated herein in its entirety.

[0062] In one embodiment, the one or more substrate arrays 200 are grouped into a first substrate array assembly 120a and at least one 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 a first substrate array assembly 120a and at least one second substrate array assembly 120b. For example, the pitch spacing of the one or more substrate arrays 200 can be inspected according to a desired tolerance. For example, the pitch spacing tolerance can include one or more unit number micron feature tolerances.

[0063] 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 one second substrate array assembly 120b are arranged into at least one second substrate array stack. In another embodiment, the at least one second substrate array stack is mounted in at least one second frame. In another embodiment, the first frame and the at least one second frame are coupled to form the column assembly 110.

[0064] In another embodiment, one or more alignment errors are reduced via a least squares 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 a first substrate array stack, arranging the one or more substrate arrays 200 of the at least one second substrate array assembly 120b into at least one second substrate array stack, and / or coupling the first frame and the at least one second frame together. For example, the one or more alignment errors can 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.

[0065] In one embodiment, 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, one or more substrate arrays 200 of the at least one second substrate array assembly 120b are arranged into at least one second bonded substrate array stack. In another embodiment, the first bonded substrate array stack and the at least one second bonded substrate array stack are bonded to form the pillar assembly 110.

[0066] In another embodiment, one or more alignment errors are reduced via a least squares best fit alignment process when performing at least one of arranging one or more substrate arrays 200 of the first substrate array assembly 120a into a first bonded substrate array stack, arranging substrate arrays 200 of the at least one second substrate array assembly 120b into at least one second bonded substrate array stack, and / or bonding the first bonded substrate array stack and the at least one second bonded substrate array stack. For example, the one or more alignment errors can 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.

[0067] In one embodiment, 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, one or more substrate arrays 200 of the at least one second substrate array assembly 120b are arranged into at least one second substrate array stack. In another embodiment, the at least one second substrate array stack is mounted in the same frame.

[0068] In another embodiment, one or more alignment errors are reduced via a least squares best fit alignment process when performing at least one of arranging one or more substrate arrays 200 of the first substrate array assembly 120a into a first substrate array stack or arranging one or more substrate arrays 200 of the at least one second substrate array assembly 120b into at least one second substrate array stack. For example, the one or more alignment errors can 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.

[0069] Figure 2B and 2C A substrate array 200 of one or more substrate arrays in accordance with one or more embodiments of the present disclosure is described.

[0070] In one embodiment, the substrate array 200 includes a composite layer 202 having 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 can 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 co-firing ceramics. In another embodiment, the composite layer 202 is formed from a plurality of substrate layers via a fabrication process. For example, the fabrication process can include, but is not limited to, pressing the plurality of substrate layers together, sintering the plurality of substrate layers together, and / or bonding the plurality of substrate layers together via a co-firing process.

[0071] In another embodiment, the substrate array 200 includes one or more electrical contact layers 204 coupled to one or more of the top and / or bottom surfaces of the composite layer 202. For example, the substrate array 200 can include a contact layer 204a having one or more electrical contacts coupled to the top surface of the composite layer 202. By way of another example, the substrate array 200 can include a contact layer 204b having 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), wherein the one or more signal bonding pads are electrically isolated from the one or more ground bonding pads.

[0072] In another embodiment, the one or more contact layers 204 include a metallized coating or a metal plate. In another embodiment, the one or more contact layers 204 are coupled to the top and / or bottom surfaces of the composite layer 202 via a fabrication process. For example, the fabrication process can include, but is not limited to, a pressing process, a sintering process, an adhesive process (e.g., via epoxy bonding), a thick film process, and / or a thin film process. In another embodiment, the one or more contact layers 204 are configured to prevent false charging and negative electron beam interactions.

[0073] 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.

[0074] In another embodiment, the one or more ground traces 220 are electrically coupled to one or more ground bonding pads in the one or more contact layers 204 via the one or more ground vias 222. In another embodiment, the one or more signal traces 230 are electrically coupled to one or more signal bonding pads in the one or more contact layers 204 via the one or more signal vias 232.

[0075] It should be noted herein that although one or more ground vias 222 and one or more signal vias 232 are shown in the same cross-section of the substrate array 200, the one or more ground vias 222 and one or more signal vias 232 may be arranged such that the cross-section of the substrate array 200 will only contain one or more ground vias 222 or one or more signal vias 232. Additionally, it should be noted herein that although one or more ground pads and one or more signal pads in one or more contact layers 204 are shown in the same cross-section of the substrate array 200, the one or more ground pads and one or more signal pads in one or more contact layers 204 may be arranged such that the cross-section of the substrate array 200 will only contain one or more ground pads or one or more signal pads. Therefore, the above description should not be construed as limiting the scope of the invention, but is merely illustrative.

[0076] In another embodiment, one or more electrical components 206 are electrically coupled to one or more electrical contact pads 208. For example, one or more ground traces 220 may be electrically coupled to one or more ground contact pads 208. By another example, one or more signal traces 230 may be electrically coupled to one or more signal contact pads 208.

[0077] In another embodiment, one or more electrical contact pads 208 are positioned on a portion of the top and / or bottom surface of the composite layer 202 that is not shielded by the contact layer 204 (e.g., an unshielded portion of the substrate array 200). However, it should be noted herein that a large portion of the top and / or bottom surface of the composite layer 202 is shielded to prevent incorrect charging.

[0078] In one embodiment, one or more pillar electron optical elements 210 are bonded to the substrate array 200. For example, one or more pillar electron optical elements 210 may be bonded to the top and / or bottom surface of the substrate array 200. By another example, one or more pillar electron optical elements 210 may be bonded to specific grounding pads and specific signaling pads coupled to the top or bottom surface of the substrate array 200. In another embodiment, one or more pillar electron optical elements 210 are bonded to the substrate array 200 via a bonding process. For example, the bonding process may include (but is not limited to) soldering, brazing, or adhesive processes (e.g., via epoxy bonding).

[0079] In another embodiment, at least some of the one or more pillar electron optical elements 210 are fully fabricated before being bonded to the substrate array 200. In another embodiment, at least some of the one or more pillar electron optical elements 210 are partially fabricated via a first set of manufacturing processes before being bonded to the substrate array 200, and fully fabricated via a second set of manufacturing processes after being bonded to the substrate array 200. It should be noted that the first set of manufacturing processes and the second set of manufacturing processes will be described in further detail herein.

[0080] In another embodiment, the one or more column electron optical elements 210 are inspected to meet individual tolerances. For example, the individual tolerances can include one or more unit number micron feature tolerances. In another embodiment, the one or more column electron optical elements 210 are aligned via an alignment process when bonded to the substrate array 200. For example, the alignment process can include, but is not limited to, an alignment process for aligning a plurality of lithographic target features or an optical overlay alignment process.

[0081] Figures 3A to 3C A partially fabricated multipole electron beam deflector 210 is illustrated in accordance with one or more embodiments of the present disclosure.

[0082] In one embodiment, the multipole electron beam deflector 210 includes a cylindrical portion 302 and a disc portion 306. For example, the cylindrical portion 302 can be inserted into a hole of the substrate array 200 when the multipole electron beam deflector 210 is bonded to the substrate array 200.

[0083] In another embodiment, the multipole electron beam deflector 210 includes a hole 304 drilled through a top of the cylindrical portion 302 and a bottom of the disc portion 306. For example, the hole 304 can allow the electron beam 103 to pass through the multipole electron beam deflector 210. In another embodiment, the hole 304 has one or more critical tolerances. For example, the one or more critical tolerances can include, but are not limited to, a hole diameter and / or a hole shape.

[0084] In another embodiment, the multipole electron beam deflector 210 includes one or more slots 308. For example, the one or more slots 308 can be partially cut into the multipole electron beam deflector 210 such that the one or more slots 308 cut through the cylindrical portion 302 and the disc portion 306 of the multipole electron beam deflector 210 and do not extend to an edge of the disc portion 306. It is noted herein that if the one or more slots 308 extend to the edge of the disc portion 306, the multipole electron beam deflector 210 will be segmented into a plurality of individual electron beam deflector poles.

[0085] In another embodiment, the multipole electron beam deflector 210 includes a raised region 310 on an outer region of the disc portion 306. For example, the raised region 310 can offset an inner region of the disc portion 306 from a top or bottom surface of the substrate array 200 by a distance equal to a height of the raised region 310. In another embodiment, the multipole electron beam deflector 210 includes one or more grooves 312 in the raised region 310. For example, the one or more grooves 312 in the raised region 310 can be a working region for one or more post-bonding fabrication processes that are used to ensure that the one or more post-bonding fabrication processes do not damage the substrate array 200 (or otherwise interfere with the operation of the substrate array 200).

[0086] Figure 3D A set of fully fabricated multipole electron beam deflectors bonded to a substrate array 200 is illustrated in accordance with one or more embodiments of the present disclosure.

[0087] In one embodiment, one or more partially fabricated multipole electron beam deflectors 210 are bonded to the contact layer 204 of the substrate array 200. In another embodiment, one or more slots 308 extend to the edges of one or more partially fabricated multipole electron beam deflectors 210 at one or more grooves 312 via a dicing process that segments the one or more partially fabricated multipole electron beam deflectors 210 into individual electron beam deflector poles 210a to thereby fully fabricate one or more multipole electron beam deflectors 210. For example, one or more partially fabricated multipole electron beam deflectors 210 can include, but are not limited to, 2 to 12 slots 308 that, when extended to the edges of the multipole electron beam deflectors 210, segment the partially fabricated multipole electron beam deflectors 210 into 4 to 24 individual electron beam deflector poles (e.g., resulting in quadrupole electron beam deflectors, octupole electron beam deflectors, and the like) to fully fabricate one or more multipole electron beam deflectors 210.

[0088] Advantages of embodiments of the present disclosure include fabricating and aligning a multi-column SEM system with reduced pitch spacing and tighter tolerances. Advantages of the present disclosure also include forming a better matching substrate array assembly by inspecting a substrate array and classifying the substrate array based on the inspection results. Advantages of the present disclosure also include improving yield of fabricated electron-optical elements by partially fabricating the electron-optical elements via a first set of fabrication processes, inspecting the partially fabricated electron-optical elements, classifying the partially fabricated electron-optical elements into matching groups based on the inspection results, aligning the matching groups 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.

[0089] Figure 4 A process flow diagram illustrating a method 400 for fabricating a column assembly 110 of a multi-column SEM system 100 is depicted. The method can also include any other steps that can be performed by the output acquisition subsystem and / or computer subsystem(s) or system described herein.

[0090] In step 402, one or more substrate arrays 200 are formed. In one embodiment, forming 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 substrate layers 202 are made of 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.

[0091] In another embodiment, forming one or more substrate arrays 200 includes forming a composite substrate 202 from a plurality of substrate layers. For example, forming a composite substrate from substrate layers can include, but is not limited to, pressing substrate layers together, sintering substrate layers together, or bonding substrate layers together via a co-firing process. In another embodiment, forming one or more substrate arrays 200 includes drilling a plurality of holes 201 in the composite substrate 202.

[0092] In another embodiment, forming one or more substrate arrays 200 includes coupling one or more contact layers 204 to at least one of a top surface or a bottom surface of the composite substrate 202, where the one or more contact layers 204 include a metallized coating and / or a metal plate. For example, coupling one or more contact layers 204 can include a pressing process, a sintering process, a bonding process, a thick film process, and / or a thin film process. For example, the bonding process can be, but is not limited to, using an epoxy bond. 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 can be electrically coupled to the one or more ground bonding pads via the one or more ground vias 222. In another embodiment, the contact layer 204 includes 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 can be electrically coupled to the one or more signal bonding pads via the one or more signal vias 232.

[0093] 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 the one or more column electron optical elements 210 to a particular ground bond pad of the one or more ground bond pads and a particular signal bond pad of the one or more signal bond pads coupled to at least one of a top surface or a 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 bond pad and the particular signal bond pad can include, but is not limited to, a soldering process, a brazing process, or an adhesive process (e.g., via an epoxy bond). By way of another example, bonding each of the one or more column electron optical elements 210 to the particular ground bond pad and the particular signal bond pad can include an alignment process, such as, but not limited to, an alignment process for aligning a plurality of lithography target features or an optical overlay alignment process.

[0094] In another embodiment, at least some of the column electron optical elements 210 are fully fabricated prior to being bonded to the particular ground bond pad and the particular signal bond pad. In another embodiment, at least some of the column electron optical elements 210 (e.g., multipole electron 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 the particular ground bond pad and the particular signal bond 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 bond pad and the particular signal bond pad.

[0095] For example, the first set of fabrication processes can include drilling a hole 304 in the column electron optical element 210 based on one or more critical tolerances (e.g., aperture and / or hole shape), and cutting one or more slots 308 in the column electron optical element 210. For example, the one or more slots 308 can 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 can pass through a portion of the hole 304. Furthermore, the first slot 308 and the at least a second slot 308 can not extend to an edge of the column electron optical element 210. By way of another example, the second set of fabrication processes can include cutting one or more slots 308 that extend to an edge of the column electron optical element 210 such that the column electron optical element 210 is segmented into one or more electron beam deflector poles (e.g., 2 to 12 slots segment the column electron optical element 210 into 4 to 24 electron beam deflector poles).

[0096] In step 404, the formed substrate array 200 is sorted into a first substrate array assembly 120a and at least a second substrate array assembly 120b. In one embodiment, the formed substrate array 200 is inspected prior to sorting the formed substrate array 200 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 array 200 is based on the inspection results.

[0097] 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 one or more column electron-optical elements 210 of one or more substrate arrays 200 bonded to the first substrate array assembly 120a and the at least a second substrate array assembly 120b, as previously described herein.

[0098] In one embodiment, forming the column assembly 110 includes arranging the first substrate array assembly 120a into 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 into at least a second substrate array stack. In another embodiment, forming the column assembly 110 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, when 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 is performed, one or more alignment errors are reduced via a least-squares best-fit alignment process. For example, the one or more alignment errors can 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.

[0099] In one embodiment, forming the column assembly 110 includes arranging the first substrate array assembly 120a into a first bonded substrate array stack. In another embodiment, forming the column assembly 110 includes arranging at least one second substrate array assembly 120b into at least one 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 one second bonded substrate array stack. In another embodiment, when performing at least one of arranging the first substrate array assembly 120a, arranging the at least one second substrate array assembly 120b, or bonding the first bonded substrate array stack and the at least one second bonded substrate array stack, one or more alignment errors are reduced via a least squares best fit alignment process. For example, the one or more alignment errors can 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.

[0100] In one embodiment, forming the column assembly 110 includes arranging the first substrate array assembly 120a into 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 100 includes arranging at least one second substrate array assembly 120b into at least one second substrate array stack. In another embodiment, forming the column assembly 110 includes mounting the at least one second substrate array assembly in the same frame. In another embodiment, when performing at least one of arranging the first substrate array assembly 120a or arranging the at least one second substrate array assembly 120b, one or more alignment errors are reduced via a least squares best fit alignment process. For example, the one or more alignment errors can 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.

[0101] Those skilled in the art will recognize that the components, e.g. operations, apparatus, objects, and the like, described herein can be a result of the application of known concepts, e.g. principles, to a known field, e.g. technology. Thus, as used herein, the stated examples and their accompanying discussion are intended to represent the more general class of which they are a part. In general, any stated example, and its accompanying discussion, is intended to represent the class of which it is a part and not to be limited to the specific components, e.g. operations, apparatus, and objects, described.

[0102] With respect to substantially any plural and / or singular term herein, those skilled in the art can convert the plural to the singular and / or the singular to the plural, depending on the context and / or application. For clarity, various singular / plural permutations are not explicitly set forth herein.

[0103] The objects described herein sometimes refer to different components contained within or connected to different other components. It should be understood that such architectures depicted are merely illustrative, and many other architectures can in fact be implemented to achieve the same functionality. Conceptually, any arrangement of components used to achieve the same functionality is effectively “associated” to achieve the desired functionality. Therefore, any two components combined herein to achieve a particular functionality can be considered “associated” with each other to achieve the desired functionality, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered “operably connected” or “operably coupled” with each other to achieve the desired functionality, and any two components that can be so associated can also be considered “operably coupled” with each other to achieve the desired functionality. Specific examples of operable coupling include (but are not limited to) physically mating and / or physically interacting components and / or wirelessly interacting and / or logically interacting components.

[0104] In some instances, one or more components may be referred to herein as “configured to…”, “configurable to…”, “operable / operated to…”, “adaptable / adaptable”, “capable of…”, “can be with / with…”, etc. Those skilled in the art will recognize that, unless the context otherwise requires, such terms (e.g., “configured to…”) generally cover active state components and / or passive state components and / or standby state components.

[0105] Although specific aspects of the subject matter described herein have been shown, described and demonstrated by way of illustration, it will be recognized that the details are susceptible to modifications and alternatives, and therefore, specific exercises should not be read into the description as requirements or limitations therefrom. It will be recognized not to depart from the spirit of the subject matter described herein and that modifications and alternatives are possible. It will be understood by those within the art that, in general, terms used herein, and especially to the immediately preceding claims, are intended to be interpreted broadly. Thus, for example, the terms "includes", "including" and "has" are intended to be open-ended and do not exclude the presence of non-recited items. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such intent will be explicitly recited in the claim. For example, the phrase "at least one of A and B" will be understood to mean A or B or A and B. Any patents or publications mentioned in this specification are indicative of the levels of those skilled in the art those prior to the filing date of the subject patent application. These patents or publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. Any theory, mechanism, exercise, composition of matter, means, methods, and / or operations that incorporates benefits, advantages, preferred applications and / or activities will be deemed as being within the scope of the present subject matter.It will be further understood by those skilled in the art that, unless otherwise indicated herein, the transition phrase "comprising," as well as any variations thereof, such as "comprise" and "comprises," is intended to be inclusive of the subject matter that follows, encompassing the possibility of reciting only a single element of the recited step or group of steps, or a plurality of elements of the recited step or group of steps. For example, the phrase "comprising A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

[0106] With respect to the appended claims, those skilled in the art will recognize that changes can be made in the element described therein without departing from the scope of the disclosure. It will be understood that any described process can be performed in a different order. Furthermore, unless otherwise indicated herein, the terms "comprising" or "comprises," and variations thereof such as "comprise" or "comprises," are not intended to exclude other additives, components, integers or steps. Furthermore, unless otherwise indicated herein, the terms "coupled" and "coupling" and variations thereof are intended to describe a direct connection between items, an indirect connection between items, or an adapter between items.

[0107] It is believed that the present application and many of its attendant advantages will be understood by the foregoing description, and it will be apparent that various changes can 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 exemplary and it is intended to encompass and embrace various changes without departing from the spirit and scope of the presently disclosed subject matter. Therefore, the scope of the present application should not be determined from the described form but from the following claims.

Claims

1. A multi-column scanning electron microscope (SEM) system, comprising: a column assembly, comprising: a first substrate array assembly; and at least a second substrate array assembly; wherein a substrate array in 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 two or more electron beams configured to be generated by two or more electron beam sources; a plurality of electrical components embedded within the plurality of substrate layers; at least one ground bond pad coupled to at least one of a top surface or a bottom surface of the composite substrate; at least one signal bond pad coupled to at least one of the top surface or the bottom surface of the composite substrate; a plurality of column electron optical elements, wherein the plurality of column electron optical elements are bonded to the composite substrate above the plurality of holes in the composite substrate, wherein each of the plurality of column electron optical elements is bonded to a particular ground bond pad and a particular signal bond pad coupled to at least one of the top surface or the bottom surface of the composite substrate, wherein the particular ground bond pad and the particular signal bond pad correspond to a respective one of the plurality of column electron optical elements, and wherein each of the plurality of column electron optical elements is segmented into one or more electron beam deflector poles by a plurality of slots, wherein each of the plurality of slots extends to an edge of each of the plurality of column electron optical elements and is formed after each of the plurality of column electron optical elements is bonded to the particular ground bond pad and the particular signal bond pad; a source assembly, comprising: the two or more electron beam sources, 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, wherein the particular electron beam source is the electron beam source corresponding to a respective one of the two or more sets of the plurality of positioners; 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 of 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 of 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 a surface of the sample.

4. The system of claim 3, wherein the two or more detector assemblies are positioned within the column assembly.

5. The system of 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 of claim 1, wherein at least one of the first substrate array assembly or the at least one second substrate array assembly includes two or more substrate arrays with at least one metal shield positioned between the two or more substrate arrays.

7. The system of claim 1, wherein the first substrate array assembly is arranged into a first substrate array stack and mounted in a first frame, wherein the at least one second substrate array assembly is arranged into a second substrate array stack and mounted in at least one second frame, wherein the first frame and the at least one second frame are coupled.

8. The system of 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 one second frame includes alignment 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 of claim 1, wherein the first substrate array assembly is arranged into a first bonded substrate array stack, wherein the at least one second substrate array assembly is arranged into at least one second bonded substrate array stack, wherein the first bonded substrate array stack and the at least one second bonded substrate array stack are bonded.

10. The system of claim 9, wherein at least one of arranging the first substrate array assembly, arranging the at least one second substrate array, or bonding the first bonded substrate array stack and the at least one second bonded substrate array stack includes alignment 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 of claim 1, wherein the first substrate array assembly is arranged into a first substrate array stack and mounted in a frame, wherein the at least one second substrate array assembly is arranged into at least one second substrate array stack and mounted in the same frame.

12. The system of claim 11, wherein arranging into the first substrate array assembly or arranging into the second substrate array stack includes alignment 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 of claim 1, wherein each set of the plurality of positioners is configured to adjust a position of the particular electron beam 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 of claim 1, wherein the plurality of electrical components embedded within the plurality of substrate layers includes 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 of claim 14, wherein at least one of the one or more ground traces, the one or more signal traces, the one or more ground vias, or the one or more signal vias are embedded into the plurality of substrate layers prior to forming the composite substrate.

16. The system of claim 14, wherein the one or more ground traces are electrically coupled to the at least one ground landing pad via the one or more ground vias.

17. The system of claim 14, wherein the one or more signal traces are electrically coupled to the at least one signal landing pad via the one or more signal vias.

18. The system of claim 1, wherein each of the plurality of column electron optical elements has an aperture that allows the electron beam to pass through, and the aperture of the each of the plurality of column electron optical elements has at least one critical tolerance, the at least one critical tolerance including at least one of an aperture size or an aperture shape.

19. A method comprising: forming a plurality of substrate arrays, wherein forming the substrate arrays of the plurality of substrate arrays includes: embedding one or more components within a plurality of substrate layers; forming a composite substrate from the plurality of substrate layers; drilling a plurality of holes in the composite substrate; coupling at least one ground landing pad to at least one of a top surface or a bottom surface of the composite substrate; coupling at least one signal landing pad to at least one of the top surface or the bottom surface of the composite substrate; bonding a plurality of column electron optical elements to a particular ground landing pad and a particular signal landing pad coupled to at least one of the top surface or the bottom surface of the composite substrate, wherein the particular ground landing pad and the particular signal landing pad correspond to a respective one of the plurality of column electron optical elements, and wherein each of the plurality of column electron optical elements is positioned over the plurality of holes in the composite substrate; classifying 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, and the method further comprises, after bonding at least some of the plurality of column electron optical elements to the particular ground landing pad and the particular signal landing pad, cutting a plurality of slots that extend to edges of the at least some of the plurality of column electron optical elements, such that each of the at least some of the plurality of column electron optical elements is segmented by the plurality of slots into one or more electron beam deflector poles.

20. The method of claim 19, wherein prior to bonding at least some of the plurality of column electron optical elements to a particular ground landing pad and a particular signal landing pad, drilling holes in the at least some of the plurality of column electron optical elements based on at least one critical tolerance, the holes allowing the electron beam to pass through, and wherein the at least one critical tolerance includes at least one of an aperture size or an aperture shape.

21. The method of claim 20, further comprising: cutting the plurality of slots in the at least some of the plurality of column electron optical elements prior to bonding the at least some of the plurality of column electron optical elements to the particular ground bonding pads and the particular signal bonding pads, 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 aperture, wherein the first slot and the at least a second slot do not extend to an edge of the at least some of the plurality of column electron optical elements.

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