Charged-particle optical module

Abstract

A charged particle optical module for a plurality of charged particle optical apparatuses configured to direct a charged particle beam along a respective beam path towards a sample position, the charged particle optical module comprising: a plurality of emitters configured to emit a respective source beam of charged particles along a respective source path; and a plurality of charged particle optical plate elements configured to operate on the source beams and a plurality of beam apertures configured for passage of the source beams are defined therein, wherein at least one charged particle optical plate element is common to the plurality of emitters, wherein the charged particle optical plate elements comprise an extractor arrangement configured to individually operate on the source beams.

Description

Cross-references to related applications

[0001] This application claims priority to EP application 24167237.7, filed on March 28, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0002] This invention relates to charged particle optical modules, multiple charged particle optical devices, charged particle optical apparatuses, evaluation devices, methods for providing source beams, methods for assembling charged particle optical modules, and multi-source modules. Background Technology

[0003] For example, in the manufacturing process of semiconductor integrated circuit (IC) chips or displays, undesirable defects may appear on the substrate (e.g., wafer) or mask. Such defects can reduce yield. Defects may occur as a consequence of various processes required to produce integrated circuits or displays, such as photolithography, etching, deposition, or chemical mechanical polishing. Defects can include patterning defects (where patterns are created beyond the pattern tolerances of the process) and particulate matter. Therefore, the extent to which defects are monitored in the manufacturing process is important. Such monitoring (or more generally, assessment) includes not only determining whether defects are present but also classifying the types of defects found.

[0004] To evaluate samples, various types of inspection or measurement systems have been used, including charged particle systems such as electron microscopes. Such evaluations for inspection may relate to defects, such as their presence and classification. Electron microscopes typically generate a probe beam (also often called a primary beam) that can be scanned over a portion of a substrate (as in a scanning electron microscope (SEM)). The interaction products resulting from the interaction of the primary beam with that portion of the substrate are collected, enabling the electron microscope to collect data representing the probed portion of the substrate. This data can be processed / rendered by, for example, the electron microscope to generate an image representation of that portion of the substrate. The collected data (e.g., the generated image representation) allows for the measurement of structures on that portion of the substrate or allows for the identification of defective structures by comparing the image representation with a reference. Such measurements can be called metrology; such defect inspections can be called inspections. Interaction products can include charged particles such as secondary electrons and backscattered electrons, which can be called signal particles (e.g., signal electrons), and can include other interaction products such as X-ray radiation.

[0005] The primary beam can be derived from the source beam emitted by the source. Multiple sources can be set up. Aligning the various components of the sources can be difficult. The goal is to reduce the time and effort required to perform alignment. Summary of the Invention

[0006] According to one aspect of the invention, a charged particle optical module for a plurality of charged particle optical devices is provided, configured to guide a charged particle beam toward a sample location along a respective beam path. The charged particle optical module includes: a plurality of emitters configured to emit respective source beams of charged particles along a respective source path; and a plurality of charged particle optical plate elements configured to operate on the source beams, and a plurality of beam apertures configured for the passage of the source beams are defined therein, wherein at least one charged particle optical plate element is shared by the plurality of emitters, and wherein the charged particle optical plate element includes an extractor arrangement configured to operate the source beams individually.

[0007] According to another aspect of the invention, a method is provided for providing a source beam for a plurality of charged particle optical devices configured to guide a charged particle beam to a sample location along a respective beam path, the method comprising: emitting a respective source beam of charged particles from a plurality of emitters along a respective source path; and operating the source beam with a plurality of charged particle optical plate elements, wherein a plurality of beam apertures configured for the passage of the source beam are defined therein, wherein at least one of the charged particle optical plate elements is shared by the plurality of emitters, wherein the operation includes individually operating the source beam using an extractor arrangement of the charged particle optical plate elements.

[0008] According to another aspect of the invention, a method is provided for assembling a charged particle optical module for a charged particle optical device configured to guide a beam of charged particles along a respective beam path to a sample location. The charged particle optical module includes: a plurality of emitters for emitting a source beam; a plurality of charged particle optical plate elements for manipulating charged particles emitted by the emitters; and spacers interlaced between adjacent charged particle optical plate elements for supporting and electrically isolating the charged particle optical plate elements, including the charged particle optical plate elements and spacers in a stack. The method includes: aligning the elements of the stack relative to the emitters, fixing the elements of the stack to each other, and fixing the stack to the emitters.

[0009] According to another aspect of the invention, a multi-source module for a multi-column electron beam system is provided, the module comprising: a plurality of emitters configured to emit a source beam of corresponding electrons, and a plurality of plate electrodes configured to operate on the source beam, with a plurality of beam apertures defined in different plate electrodes; two or more plate electrodes being shared by more than one of the emitters. Attached Figure Description

[0010] Embodiments of the invention will now be described by way of example only, with reference to the accompanying schematic diagrams, wherein...

[0011] Figure 1 This is a schematic diagram of an exemplary evaluation device;

[0012] Figure 2 Schematic depiction of, for example Figure 1 The evaluation device is a multi-beam charged particle optical instrument;

[0013] Figure 3 An array of charged particle optical devices is schematically depicted.

[0014] Figure 4 A charged particle optical module comprising multiple sources is schematically depicted.

[0015] Figure 5 The source of contrast is depicted schematically;

[0016] Figure 6 schematically depicted Figure 4 A plan view of the stacked charged particle optical modules shown;

[0017] Figure 7 schematically depicted Figure 6 The side view of the stack shown; and

[0018] Figure 8 A vacuum chamber is schematically depicted.

[0019] The accompanying drawings are schematic. In the following description of the drawings, the same or similar reference numerals refer to the same or similar parts or entities, and differences are described only with respect to individual embodiments. Although the specification and drawings are intended to guide electro-optical devices, it should be understood that these embodiments are not intended to limit this disclosure to specific charged particles. Therefore, throughout this document, references to electrons and terms relating to electrons can be more generally understood as references to charged particles and terms relating to charged particles, where charged particles are not necessarily electrons. For example, references to electro-optical devices can be more generally understood as references to charged particle optical devices. Detailed Implementation

[0020] In the semiconductor industry, there is a trend (often referred to as "Moore's Law") to reduce the physical size of structures representing circuit components on substrates and / or increase the packaging density of such structures in order to reduce the physical size of electronic devices and / or enhance their computing power. The physical size of such structures can be reduced and / or the packaging density can be increased by improving lithographic resolution. The manufacturing process of semiconductor IC chips can have hundreds of individual steps. Errors in any step of the manufacturing process can adversely affect the functionality of electronic devices. Improving the overall yield of the manufacturing process is desirable. For example, to achieve a 75% yield in a 50-step manufacturing process (where steps can represent the number of layers formed on the substrate), each individual step must have a yield greater than 99.4%. If individual steps have a yield of 95%, the overall yield of the manufacturing process will be as low as 7-8%. Rapid defect identification is desired to maintain high substrate throughput, which is defined as the number of substrates processed per hour.

[0021] Figure 1 This is a schematic diagram illustrating an exemplary evaluation apparatus 100, such as a measurement or inspection apparatus. The evaluation apparatus 100 can be configured to scan a sample using one or more electron beams. The sample can be, for example, a semiconductor substrate, a substrate made of other materials, or a mask. Electrons interact with the sample and generate interaction products. Interaction products include signal electrons (e.g., secondary electrons and / or backscattered electrons), and possibly X-ray radiation. The evaluation apparatus 100 can be configured to detect the interaction products from the sample, such that a dataset can be generated, which can be processed into an image or any other data representation of the scanned area of ​​the sample that can be generated. For clarity, embodiments focusing on the detected interaction products being signal electrons are described below. For example, during operation, the evaluation apparatus 100 can include a single beam or multiple beams (i.e., multiple beams). The component beams of a multiple beam can be referred to as sub-beams or beam waves. Multiple beams can be used to simultaneously scan different portions of the sample. When the evaluation apparatus 100 uses multiple beams, it can evaluate the sample more quickly than when it uses a single beam. For example, compared to using a single-beam device, a high throughput of sample evaluation can be achieved using a multi-beam evaluation device.

[0022] Figure 1The evaluation apparatus 100 includes a vacuum chamber 110, a loading and locking chamber 120, an electron optics device 140, an equipment front-end module (EFEM) 130, and a controller 150. The electron optics device 140 (also referred to as an electron beam device or electron device) may be located within the vacuum chamber 110. The electron optics device 140 may include electron optical equipment (described in more detail below) and an actuable stage. It should be understood that references to electron optical elements of the electron optics device 140 in the description may be considered as references to the electron optical equipment itself.

[0023] EFEM 130 includes a first loading port 130a and a second loading port 130b. EFEM 130 may include additional loading ports. For example, the first loading port 130a and the second loading port 130b may receive a substrate-front-opening transfer cassette containing a sample. One or more robotic arms (not shown) within EFEM 130 transfer the sample to the loading locking chamber 120.

[0024] Loading-lock chamber 120 is used to remove gas surrounding the sample. Loading-lock chamber 120 can be connected to a loading-lock vacuum pump system (not shown) that removes gas particles within loading-lock chamber 120. Operation of the loading-lock vacuum pump system enables the loading-lock chamber to reach a first pressure below atmospheric pressure. Vacuum chamber 110 is connected to a main chamber vacuum pump system (not shown), which can be the main chamber of evaluation apparatus 100. The main chamber vacuum pump system removes gas molecules from vacuum chamber 110, causing the pressure around the sample to reach a second pressure equal to or below the first pressure. Different sections of electron optics apparatus 140 can have different levels of pressure below atmospheric pressure. After the required pressure is reached, the sample leaves loading-lock chamber 120 and is transferred to electron optics apparatus 140 where the sample can be evaluated. Electron optics apparatus 140 can be evaluated using a single beam or multiple beams. Alternatively, an array of electron optics devices comprising multiple electron optics devices can be used, further referred to as a multi-column electron array, wherein, for example, during operation, each electron optics device (or each column in a multi-column array) comprises a single beam or multiple beams.

[0025] Controller 150 is electrically connected to electro-optical device 140. Controller 150 may be a processor (such as a computer) configured to control evaluation device 100. Controller 150 may also include processing circuitry configured to perform data, signal, and image processing functions on datasets (e.g., signals implemented as such as detection signals). Controller 150 may therefore include processing circuitry configured to perform processing functions on signals, images, and other data generated in evaluation device 100. Although controller 150 is... Figure 1The device is shown as being located outside the structure comprising the vacuum chamber 110, the loading lock chamber 120, and the EFEM 130; however, it should be understood that the controller 150 may be part of this structure. The controller 150 may be located in one of the components of the evaluation device 100, or the controller 150 may be distributed across at least two of the components.

[0026] Figure 2 This is a schematic diagram illustrating an exemplary electro-optical device 140. The electro-optical device 140 can be configured as follows: Figure 1 This is part of the evaluation apparatus 100. The electron-optical apparatus 140 includes a source 201 and an electron-optical device 230 (which may also be referred to as an electron-optical column). The source 201 may include an emitter (not shown), which may be a cathode, and an extractor and / or an anode (not shown). During operation, the source 201 is configured to emit electrons from the emitter. The electrons may be extracted or accelerated by the extractor and / or the anode to form a source beam 202.

[0027] Electron optics device 230 can be configured to convert source beam 202 into multiple primary beams 211, 212, 213 (which may be referred to as sub-beams or beam waves). Electron optics device 230 can be configured to guide primary beams 211, 212, 213 along corresponding beam paths to the sample position of sample 208. Although three beams are illustrated, the number of beams can be on the order of hundreds or thousands, for example, up to 20,000 per electron optics device 140. Multiple beams can be collectively referred to as multiple beams or beam grids. Different beams can be arranged in a pattern relative to each other in the beam grid. The pattern of the beam grid can be referred to as an array. Electron optics device 230 has a field of view that can be defined as an area on the surface of sample 208 within which the primary beams 211, 212, 213 can scan while the aberrations of electron optics device 230 are preserved within defined values. Alternatively, the field of view can be defined by the maximum scanning range of electron optics device 230. The field of view can be on the order of millimeters, for example, up to 20 mm at sample 208.

[0028] Electro-optical device 230 includes a plurality of electro-optical elements positioned along a beam path. The electro-optical elements are configured to manipulate the beam. For example, the electro-optical elements may be configured to lens, focus, deflect, or correct the beam. Electro-optical elements may be arranged in at least one stack of electro-optical elements. Such electro-optical elements may be positioned upstream or downstream relative to another electro-optical element. The terms upstream and downstream refer to the direction of the beam from source 201 to sample 208 during use of electro-optical device 230, which can be expressed as a direction along one or more beam paths. In embodiments, some different electro-optical elements may take the form of planar elements, such as plates 261. An electric field for manipulating the beam may be generated between two plates 261, for example, by applying different potentials to adjacent / adjacent plates 261 during use, such as along the beam path. The electric field for manipulating the beam may be generated between the surfaces of plates 261 across the beam path (e.g., between adjacent plates 261). One or more beam apertures 266 may be defined in plates 261 for the passage of one or more beams. The beam apertures 266 can be arranged in a pattern such as a regular grid (e.g., hexagons or squares). This pattern of beam apertures 266 can be referred to as an aperture array (i.e., a two-dimensional array on the surface of the plate). The pattern of the beam apertures 266 can correspond to the pattern of the beams within the beam grid. The beam apertures 266 in different plates operating on the same(multiple) beams(s) are typically aligned.

[0029] Electro-optical elements may include one or more corrector arrays. For example, a corrector array may be integrated into the shape, location, and / or size of the beam aperture 266 of plate 261. The disclosure of such corrector arrays as described in WO 2022101072 A1 is incorporated herein by reference. One or more corrector arrays may include a specific superposition of multipole deflectors having potentials applied to individual controllable electrodes. The disclosure of multipole deflector arrays in WO2012165955 is incorporated herein by reference.

[0030] One or more electro-optical elements may include apertures for paths of multiple beams. For example, the aperture may be a macroaperture for all beams. The disclosures in WO 2021156121 A1 and WO 2021204734 A1 concerning slit apertures for collimators or correctors including strip electrodes are incorporated herein by reference. One or more electro-optical elements may include one or more plate electrodes that are bent along the path of the beam grid to serve as lens arrays, corrector arrays, and / or collimator arrays, as disclosed in European Patent Application 23211553.5, filed November 22, 2023, which is incorporated herein by reference at least in relation to the use and application of bent plate electrodes.

[0031] In the current embodiment, the electron optics device 230 can form three probe spots 281, 282, and 283 on the surface of the sample 208. The electron optics device 230 can be configured to deflect primary beams 211, 212, and 213 to scan probe spots 281, 282, and 283 within individual scanning areas of the sample 208. In response to the primary beams 211, 212, and 213 incident on the sample 208, signal electrons are generated from the sample 208, which may include secondary electrons and backscattered electrons. The secondary electrons typically have an electron energy of up to 50 eV. The backscattered electrons typically have an electron energy greater than 50 eV and less than the landing energy of the primary beams 211, 212, and 213.

[0032] Electron-optical device 140 includes a sample holder 207 supporting a sample 208. The sample holder 207 supports the sample 208 for evaluation. The sample holder 207 is supported by an actuable stage 209. Electron-optical device 140 also includes a detector array 240. The detector array 240 may be part of the electro-optical device 230. For example, the detector array 240 detects signal electrons from the sample 208. The detector array 240 generates a detection signal based on the detection of the signal electrons.

[0033] In an embodiment, detector array 240 may define the surface of electro-optical device 140 facing sample 208, such as the bottom surface of electro-optical device 230. More than one detector array may be present at different locations along the path of primary beams 211, 212, 213.

[0034] Detector array 240 may include multiple detector elements, with each beam having at least one detector element. For example, a detector element may be a charge-trapping electrode (e.g., a metal plate) configured to detect at least a portion of the signal electrons. Alternatively or additionally, a detector element may include a detection diode configured to detect at least a portion of the signal electrons. Alternatively or additionally, a detector element may include a scintillator material (such as YAG) configured to convert the signal electrons into photons that can subsequently be detected. Detector elements may be arranged around beam aperture 266 in the bottom surface of electron optics device 230 to allow primary beams 211, 212, 213 to pass toward sample 208. Each detector element may include multiple detection segments, or may constitute a single sensitive surface for each beam. Detection signals generated by the detector elements may be transmitted to a processor for image generation. For example, the detection signals may represent grayscale values ​​or intensity values ​​of pixels in an image.

[0035] Detector array 240 can transmit detection signals (e.g., as imaging or detection signals) to controller 150 or to a signal processing system (not shown) that may be part of controller 150. Controller 150 or the signal processing system can be configured to generate an image of sample 208 corresponding to the scanned area. Detector array 240 can be at least partially incorporated into electro-optical device 230. Alternatively, detector array 240 can be separate from electro-optical device 230. For example, electro-optical device 140 may include a secondary electro-optical device configured to direct secondary electrons to detector array 240. In such embodiments, the secondary electro-optical device includes a beam splitter (e.g., a Wiener filter, not shown). The beam splitter can separate the path of primary electrons toward sample 208 from the path of signal electrons away from sample 208. It should be noted that such beam splitters can exist within different embodiments of electro-optical device 230 with detector arrays for directing primary electrons to the sample and signal particles to detector elements of the detector array.

[0036] Controller 150 (e.g., a control system including a distributed controller) can be connected to Figure 2 The various parts (e.g., components) of the electro-optical device 140 include the source 201, detector array 240, electro-optical device 230, and actuable stage 209. The controller 150 can perform various image processing and signal processing functions. The controller 150 can also generate various control signals to manage the operation of the evaluation device 100.

[0037] Figure 3 An array of electro-optical devices 299 is schematically depicted. In an embodiment, Figure 1 The evaluation apparatus 100 includes an electro-optical device array 299, rather than an electro-optical device 140. This electro-optical device array 299 is also referred to as a multi-pillar array. Different pillars (or electro-optical devices 230) can include multiple beams, such as a beam grid, in use. In this embodiment, the electro-optical device array 299 includes... Figure 2 Multiple electro-optical devices 230 of the type shown.

[0038] In an embodiment, one or more electro-optical elements may be shared among more than one electro-optical device 230 of the electro-optical device array 299. An electro-optical element may include one or more plates 261, wherein multiple beam apertures 266 are defined for corresponding beam paths. In an embodiment, one or more sources 201 may be shared among the multiple electro-optical devices 230 of the electro-optical device array 299. Sources may be included in a source array with different sources to generate source beams for different corresponding electro-optical devices 230.

[0039] Electro-optical device 230 can simultaneously focus multiple beams onto different regions of the same sample 208. In different embodiments, the electro-optical device 230 of the electro-optical device array 299 can project a single beam onto the sample 208.

[0040] Each electro-optical device 230 of the electro-optical device array 299 can be configured in any manner described herein. The disclosure in WO 2022008286 A1 concerning how objectives are incorporated and adapted for use in multi-device arrangements is incorporated herein by reference. The disclosure in WO 2021165135 A1 concerning multi-device arrangements including a collimator located at or near the intermediate focal point is incorporated herein by reference.

[0041] In embodiments, any electro-optical element or group of electro-optical elements may be replaceable within the electro-optical device 140 or field-replaceable. Field-replaceable means that the electro-optical element or group of electro-optical elements can be replaced with minimal disassembly of the electro-optical device 140. In embodiments, the electro-optical device 140 includes at least one module. Each module includes a set of adjacent electro-optical elements. The electro-optical elements of a module may be fixed to each other, for example, as a stack.

[0042] Features in the electron optics plate can be fabricated using techniques from microelectromechanical systems (MEMS), i.e., using MEMS fabrication techniques. MEMS are miniaturized mechanical and electromechanical components made using microfabrication techniques. As an example only, a collimator array can be formed using MEMS fabrication techniques to make it spatially compact. As another example, a scanning deflector array can be formed using MEMS fabrication techniques.

[0043] A power supply can be configured to power the evaluation device 100 and / or the electro-optical device 140. For example, such a power supply should be able to apply a corresponding potential to the electrodes of the lens of the electro-optical device 230.

[0044] In one embodiment, controller 150 is configured to control electro-optical device 230. Controller 150 may be configured to control the potential of electrodes applied to the lenses of electro-optical device 230.

[0045] In an embodiment, controller 150 is configured to control actuable stage 209 to move sample 208 during sample inspection. At least during sample inspection, controller 150 can cause actuable stage 209 to move sample 208 continuously along a direction, such as at a constant speed, which can be referred to as a scan. The speed of actuable stage 209 can be referred to as a movement rate. Controller 150 can control the movement of actuable stage 209 to vary the speed of movement of sample 208 relative to the beam path depending on one or more parameters. Controller 150 can control the deflection of a scan deflector such that the beam path moves relative to actuable stage 209, and thus moves across the surface of sample 208. Controller 150 can vary the beam deflection of the scan deflector depending on one or more parameters, and thus vary the scanning of primary beams 211, 212, 213 on sample 208. For example, controller 150 can control the speed and / or direction of movement of the scan deflector and / or the actuable stage 209 based on the characteristics of the evaluation process. The disclosure in EP4086933 A1 regarding a combined stepping and scanning strategy for the stage and scan deflector is incorporated herein by reference. The movement rate may include the stepping frequency and / or the stage scan rate at different times.

[0046] like Figure 2 As shown, in this embodiment, the electro-optical device 140 includes an electro-optical module 200. The electro-optical module 200 may include a source 201.

[0047] like Figure 3 As shown, in this embodiment, the electro-optical device array 299 includes an electro-optical module 200. The electro-optical module 200 may include a plurality of sources 201. For example, the electro-optical module 200 may include a plurality of sources 201 of a plurality of corresponding electro-optical devices 230.

[0048] Figure 4 An electro-optical module 200 according to an embodiment of the present invention is schematically depicted. The electro-optical module 200 may be referred to as a multi-source module. The electro-optical module 200 may include a plurality of emitters 21. Figure 3 As shown, in this embodiment, the electron optics module 200 is for a plurality of electron optics devices 230. The electron optics devices 230 can be configured to guide an electron beam along a corresponding beam path to the sample location where the sample 208 is positioned.

[0049] like Figure 4 As shown, in this embodiment, the electro-optics module 200 includes a plurality of emitters 21. Each emitter 21 can be configured to emit a corresponding source beam 202 of electrons. The source beam 202 can be emitted along a corresponding source path. The source path can be the path along which the electrons of the source beam 202 travel. Figure 4Two transmitters 21 of the corresponding source 201 are schematically shown. The two transmitters 21 are shown to facilitate explanation of the features of the electro-optical module 200. The electro-optical module 200 may include at least three, optionally at least five, optionally at least ten, optionally at least twenty, optionally at least fifty, optionally at least one hundred, optionally at least two hundred, optionally at least five hundred, and optionally at least one thousand transmitters 21 of the corresponding source 201.

[0050] In an embodiment, each source 201 is configured to generate a source beam 202 for a corresponding electro-optical device 230. Each electro-optical device 230 may include one or more electro-optical elements downstream of the source 201. In an embodiment, the source 201 includes a Schottky source. Additionally or alternatively, the source 201 may include a cold field emitter.

[0051] like Figure 4 As shown, in this embodiment, the electro-optics module 200 includes a plurality of electro-optical plate elements 24 to 26. The electro-optical plate elements 24 to 26 are configured to operate on the source beam. For example, the electro-optical plate elements 24 to 26 may help define one or more electromagnetic fields that influence the electrons in the source beam.

[0052] like Figure 4 As shown, in this embodiment, a plurality of beam apertures 266 are defined in the electro-optical plate elements 24 to 26. The beam apertures 266 are configured for the source beam to pass through. Figure 4 As shown, in this embodiment, the beam aperture 266 is aligned with the transmitter 21.

[0053] like Figure 4 As shown, in one embodiment, source 201 includes a corresponding emitter 21. In another embodiment, the electron optics plate element includes an extractor arrangement 25. The extractor arrangement 25 is configured to operate on the source beam. In one embodiment, during operation, emitter 21 is configured to emit electrons. Electrons can be extracted or accelerated by the extractor arrangement 25 to form source beam 202.

[0054] like Figure 4 As shown, in this embodiment, at least one of the electron optical plate elements 24 to 26 is shared by a plurality of transmitters 21. Figure 4 As shown, in this embodiment, at least two of the electron optical elements 24 to 26 are shared by a plurality of transmitters 21. At least one of the electron optical elements 24 to 26 is shared by all transmitters 21 of the electron optical module 200. Alternatively, at least one of the electron optical elements 24 to 26 is shared by a subset of the transmitters 21 of the electron optical module 200.

[0055] like Figure 4As shown, in this embodiment, electron optical plate elements 24 to 26 extend across the source path of the source beam. Electron optical plate elements 24 to 26 may extend between adjacent emitters 21. Figure 4 As shown, in an embodiment, the electron optical plate elements 24 to 26 may extend substantially perpendicular to the source path of the source beam emitted by the transmitter 21.

[0056] like Figure 4 As shown, in this embodiment, the electron optical plate elements 24 to 26 are substantially planar. Electron optical plate elements 24 to 26 may include a main planar surface. An electromagnetic field can be established between the opposing surfaces. The electromagnetic field may affect the electrons in the source beam emitted by emitter 21.

[0057] Electro-optical elements 24 to 26 need not be completely planar. For example, one or more of the electron optical elements 24 to 26 may be curved, such as bowl-shaped. Such a bowl-shaped electron optical element has a plate-like shape.

[0058] In an embodiment, the extractor arrangement 25 is configured to operate individually on the source beams. The extractor arrangement 25 can help define one or more electromagnetic fields that influence electrons in the source beams. The extractor arrangement 25 can be configured such that at least one electromagnetic field can be different for source beams from different emitters 21. For example, the extractor arrangement 25 can be arranged such that the magnitude and / or shape of the electromagnetic field can be different for different source beams.

[0059] Embodiments of the present invention are intended to facilitate easier alignment of emitter and extractor electrodes of multiple sources 201. Embodiments of the present invention are also intended to reduce the time required to align the emitter and extractor electrodes of sources 201. For example, during the assembly of the electro-optics module 200, the emitter 21 can be aligned relative to the extractor arrangement 25. Sources 201 can then be integrated into the electro-optics device array 299, for example, as... Figure 3 As shown. By aligning the emitter 21 relative to the extractor arrangement 25 during the assembly of the electro-optics module 200, it may not be necessary to align the emitter relative to the extractor electrodes after the source 201 has been integrated into the electro-optics device array 299.

[0060] Embodiments of the present invention are intended to improve the accuracy of beam control over source beams generated by multiple sources 201. By operating the source beams individually using the extractor arrangement 25, the beam current of the source beams can be controlled individually. For example, multiple sources 201 can be configured to have more consistent beam currents relative to each other.

[0061] Figure 5 Source 201, used as a comparative example, is depicted schematically. Figure 5As shown, source 201 may include an emitter 21 with a tip 22, a suppressor 24, and an extractor electrode 25. Source 201 may include a ceramic component 51 and a source body 50. Source body 50 may include a metal (such as stainless steel). Figure 5 As shown, electro-optical elements such as the suppressor 24 and the extractor electrode 25 are not plate-shaped. Aligning the emitter 21 with respect to the extractor electrode 25 is difficult and takes a long time.

[0062] Figure 6 schematically depicted Figure 4 Plan view of the stack 23 of the electron optical plate elements 24 to 26 shown. Figure 7 A side view of the stack 23 of electron optical plate elements 24 to 26 is schematically depicted. Figure 7 The side view shown is along Figure 6 The cross-sectional view shown is captured by the dotted line.

[0063] like Figure 4 , Figure 6 and Figure 7 As shown, in this embodiment, the electro-optics module 200 includes a plurality of spacers 33, 36. The spacers 33, 36 are configured to space the plurality of electro-optics plate elements 24 to 26 apart from each other.

[0064] For example, in one embodiment, the electron optics plate element includes a suppressor 24. The suppressor 24 can be shared by multiple emitters 21. The suppressor 24 can be configured to suppress any unwanted electron flow. Figure 4 As shown, in this embodiment, the electron optics plate element includes an anode 26. For example, an emitter 21 may form a corresponding cathode. During operation, the emitter 21 can be configured to emit electrons. The electrons can be accelerated by the anode 26 to form a source beam. Figure 4 As shown, in this embodiment, the anode 26 is shared by multiple emitters 21. For example, Figure 4 The anode 26 shown is shared by the two sources 201 shown.

[0065] For example, Figure 4 A plurality of spacers 33 configured to space the suppressor 24 from the extractor arrangement 25 are schematically depicted. As another example, Figure 6 and Figure 7 A plurality of spacers 36 configured to space the suppressor 24 from the anode 26 are schematically depicted. In embodiments, other pairs of electro-optical plate elements are spaced apart from each other by one or more spacers. For example, in an embodiment, the electro-optical module 200 includes one or more spacers configured to space the extractor arrangement 25 from the anode 26.

[0066] In an embodiment, the electro-optical plate elements include one or more electro-optical plate elements in addition to the suppressor 24, the extractor arrangement 25, and the anode 26. In an embodiment, the suppressor 24 may be omitted. In an embodiment, the anode 26 may be omitted. In an embodiment, the electro-optical module 200 includes one or more spacers configured to space such other electro-optical plate elements apart from each other, and / or space them apart from one or more of the suppressor 24, the extractor arrangement 25, and the anode 26.

[0067] like Figure 4 As shown, in an embodiment, each emitter 21 includes a tip 22. The emitter 21 is configured to emit electrons from the tip 22. Figure 4 As shown, in this embodiment, the tip 22 is positioned upstream of the extractor arrangement 25. Figure 4 As shown, in one embodiment, the tip 22 of the transmitter 21 extends through a beam aperture 266 defined in at least one electro-optical plate element (e.g., suppressor 24). Figure 4 As shown, in an embodiment, the distance between the tip 22 of the transmitter 21 and the extractor arrangement 25 is less than the distance between the extractor arrangement 25 and an electro-optical plate element (e.g., suppressor 24) upstream of the extractor arrangement 25.

[0068] In embodiments, spacers 33, 36 are configured to mechanically support electron optical plate elements relative to each other. For example, spacers 33, 36 may be fixed to electron optical plate elements 24 to 26. Electron optical plate elements 24 to 26 may be fixed relative to each other via spacers 33, 36. Embodiments of the invention are contemplated to improve the mechanical stability of a plurality of sources 201, such as electrode stacks included within the plurality of sources. Additionally or alternatively, the electron optical module 200 may include one or more frames configured to mechanically support electron optical plate elements relative to each other. Such frames are optional. Spacers 33, 36 may provide sufficient mechanical support for electron optical plate elements 24 to 26.

[0069] In an embodiment, spacers 33, 36 are configured to electrically isolate the electro-optical plate elements 24 to 26 from each other. For example, spacers 33, 36 may be arranged such that a gap is formed between adjacent electro-optical plate elements 24 to 26. Spacers 33, 36 may comprise an electrically insulating material, such as quartz. Spacers 33, 36 may be configured to reduce the likelihood of undesirable electrical breakdown between the electro-optical plate elements 24 to 26.

[0070] During operation of the electro-optics module 200, electro-optical plate elements 24 to 26 can be maintained at different potentials. For example, one or more power supplies can be electrically connected to the electro-optical plate elements 24 to 26. The one or more power supplies can be configured to apply a potential to each of the electro-optical plate elements 24 to 26. For example, the controller 150 of the electro-optical device 140 can be configured to control one or more power supplies, thereby controlling the potential of the electro-optical plate elements 24 to 26. Embodiments of the present invention are intended to reduce the possibility of undesirable electrical breakdown.

[0071] In an embodiment, spacers 33 and 36 are configured to mechanically support the extractor arrangement 25 relative to the beam path of the source beam. For example, spacer 33 may be configured to mechanically support the extractor arrangement 25 at a predetermined distance from the suppressor 24 for a corresponding source beam emitted from a corresponding transmitter 21. In an embodiment, spacers 33 and 36 are configured to mechanically support the extractor arrangement 25 individually relative to the beam path of the source beam, such that the extractor arrangement 25 is configured to operate on the source beam individually. By controlling the position of the extractor arrangement 25 relative to the beam path of the source beam, the extractor arrangement can affect the source beam differently for different source beams. Embodiments of the present invention are expected to improve the accuracy of beam control of corresponding source beams.

[0072] In this embodiment, spacer 33 is configured to shape extractor arrangement 25 under thermal load during operation. During use of the electro-optics module 200, thermal loads may exist on one or more components of the electro-optics module 200. For example, electrons emitted by emitter 21 can heat the components to which they are incident. Emitter 21 can be heated to increase beam current. Heat can be radiated from emitter 21 to other components of the electro-optics module 200. Power supplied to components such as electro-optics plate elements 24 to 26 may cause these components to heat up. Such thermal loads can cause components to change shape. For example, components subjected to thermal loads may expand. This expansion can be expected.

[0073] Thermal load can cause deformation. For example, thermal load can cause deformation of one or more extractor electrodes 27 of the extractor arrangement 25. For example, during operation, the spacer can be thermally shaped. As the spacer expands, the extractor electrode 27 may be deformed.

[0074] In an embodiment, the electro-optical module 200 is calibrated such that anticipated thermal expansion is intentionally used to shape the extractor arrangement 25. For example, in an embodiment, spacer 33 is positioned relative to at least a portion of the extractor electrodes 27 in the extractor arrangement 25 such that, under thermal loads applied during operation, the extractor electrodes 27 included in the extractor arrangement 25 individually operate the source beam. In an embodiment, the size of spacer 33 is selected to control the position of the extractor arrangement 25 (e.g., the extractor electrodes 27 of the extractor arrangement 25) relative to the emitter 21.

[0075] In an embodiment, the extractor arrangement 25 includes a plurality of extractor electrodes 27, such as... Figure 4 As shown. In Figure 4 In the illustrated arrangement, each emitter 21 of the extractor arrangement 25 includes an extractor electrode 27. The extractor electrodes 27 may be arranged in the same plane as each other. The extractor arrangement 25 may form a layer comprising a plurality of extractor electrodes 27.

[0076] In one embodiment, the extractor electrode 27 included in the extractor arrangement 25 operates individually with respect to the source beam, such that thermal expansion of the extractor electrode 27 in the extractor arrangement 25 causes a corresponding movement of the extractor electrode 27 relative to the source path of the source beam. In another embodiment, the extractor electrode 27 included in the extractor arrangement 25 operates individually with respect to the source beam, such that thermal expansion of the spacer 33 causes a corresponding movement of the extractor electrode 27 relative to the source path of the source beam. Thermal expansion caused by thermal load during operation of the electro-optics module 200 can be taken into account. Thermal expansion can be used to control the beam generated by the emitter 21 of the source 201 of the electro-optics module 200. Embodiments of the invention are intended to enable more precise and different control of different emitters 21.

[0077] like Figure 4 As shown, in this embodiment, the spacer 33 is configured to mechanically support the extractor arrangement 25. For example, as Figure 4 As shown, in one embodiment, spacer 33 is configured to mechanically support extractor arrangement 25 relative to suppressor 24. Extractor arrangement 25 may be fixed to the downstream end of spacer 33. Upstream end of spacer 33 may be fixed to suppressor 24. In an alternative embodiment, upstream end of spacer is fixed to extractor arrangement 25, and downstream end of spacer is fixed to anode 26. The position of extractor arrangement 25 relative to emitter 21 can be controlled by controlling the dimensions of spacer 33.

[0078] like Figure 6As shown, in this embodiment, for each source beam, a plurality of spacers 33 are configured to mechanically support the extractor arrangement 25. By providing a plurality of spacers 33 to mechanically support the extractor arrangement 25, the orientation of the extractor arrangement 25 relative to the transmitter 21 can be controlled more precisely. For example, undesirable tilting of the extractor arrangement 25 relative to the transmitter 21 can be reduced.

[0079] like Figure 6 As shown, in this embodiment, for each source beam, at least three spacers 33 are configured to mechanically support the extractor arrangement 25. By providing at least three spacers 33, the orientation of the plate-shaped extractor arrangement 25 relative to the transmitter 21 can be controlled. By providing three spacers 33, the plane of the extractor arrangement 25 can be controlled for each source beam. Figure 6 As shown, in one embodiment, for each source bundle, only three spacers 33 are configured to mechanically support the extractor arrangement 25. In an alternative embodiment, for each source bundle, more than three spacers 33 are provided to mechanically support the extractor arrangement 25.

[0080] like Figure 6 As shown, in this embodiment, the spacers 33 are uniformly distributed circumferentially around the source path of each source bundle. In the case where more than three spacers 33 are provided for each source bundle, in this embodiment, the spacers 33 are arranged to be uniformly distributed circumferentially around the source path.

[0081] For example, such as Figure 4 and Figure 6 As shown, in this embodiment, the extractor arrangement 25 includes a plurality of extractor electrodes 27. (As illustrated...) Figure 6 As shown, the extractor electrodes 27 are separated from each other. The extractor electrodes 27 can be arranged such that there is a gap between adjacent extractor electrodes 27. Figure 6 In the arrangement shown, there are three extractor electrodes 27. In alternative embodiments, the number of extractor electrodes 27 is at least five, optionally at least ten, optionally at least twenty, optionally at least fifty, optionally at least one hundred, optionally at least two hundred, optionally at least five hundred, and optionally at least one thousand.

[0082] like Figure 6As shown, in this embodiment, each extractor electrode 27 is configured to operate on a different source beam. For example, each extractor electrode 27 can be configured to operate separately on different source beams. By configuring different extractor electrodes 27, the extractor electrodes can be controlled individually. For example, one or more power sources can be configured to apply different potentials to different extractor electrodes 27. By applying different potentials to different extractor electrodes 27, the source beams can be controlled individually. For example, the beam currents of different source beams output by different transmitters 21 can be controlled individually.

[0083] like Figure 6 As shown, in this embodiment, each extractor electrode 27 has multiple spacers 33. For example, each extractor electrode 27 may have three spacers, such as... Figure 6 As shown. By providing three spacers 33 for each extractor electrode 27, the plane of the extractor electrode 27 can be defined by the spacers 33. By providing three spacers 33 for each extractor electrode 27, the effect of the extractor electrode 27 on the source beam can be controlled more precisely and reliably.

[0084] like Figure 4 or Figure 7 As shown, for example, in one embodiment, spacer 33 is substantially planar. For example, spacer 33 may be disk-shaped. However, it is not necessary for spacer 33 to be substantially planar. For example, spacer 33 may have a dimension along the source path larger than its dimension across the beam path. Figure 7 In the orientation, the spacer 33 may have a height that is at least equal to or greater than its width.

[0085] like Figure 7 As shown, in this embodiment, the spacer 33 is substantially parallel to one or more electron optical plate elements 24 to 26. For example, as Figure 7 As shown, spacer 33 may be substantially parallel to suppressor 24. In an embodiment, spacer 33 is substantially parallel to extractor arrangement 25 (e.g., parallel to extractor electrode 27 of extractor arrangement 25). In an embodiment, spacer 33 is substantially parallel to anode 26.

[0086] like Figure 6 As shown, in this embodiment, the spacer 33 has a substantially similar shape in at least two dimensions. For example, in a plan view, the spacer 33 may be circular. Alternatively, for example, in a plan view, the spacer 33 may be square or hexagonal. A plan view refers to a view along the source path of the source bundle. In this embodiment, the spacer 33 has a substantially similar shape in cross-section. In this embodiment, the spacer 33 has substantially the same dimensions in the direction across the source path.

[0087] like Figure 4 or Figure 7 As shown, in this embodiment, spacers 33 and 35 have edge profiles. For example, spacers 33 and 36 may include a radially inner portion 34 and a radially outer portion 35. The radially outer portion 35 is radially located outside the radially inner portion 34. The radially inner portion 34 and the radially outer portion 35 may be formed integrally with each other.

[0088] like Figure 4 and Figure 7 As shown, in this embodiment, the radially inner portion 34 and the radially outer portion 35 may have different dimensions. For example, the radially inner portion 34 may have a larger dimension than the radially outer portion 35 in the direction along the source path of the source bundle. The radially inner portion 34 and the radially outer portion 35 may be arranged such that the spacers 33, 36 have edge profiles.

[0089] like Figure 7 As shown, for example, in one embodiment, the radially inner portion 34 is fixed to the surfaces of two adjacent electro-optical plate elements 24 to 26 spaced apart by spacers 33, 36. The radially outer portion 35 may be fixed to only one of the two electro-optical plate elements 24 to 26 spaced apart by spacers 33, 36. Figure 7 As shown, in this embodiment, the radially outer portion 35 is fixed only to the upstream electro-optical plate elements of the two electro-optical plate elements spaced apart by the spacers 33 and 36. For example, the spacer 33 may have its radially outer portion 35 fixed only to the suppressor 24. The radially outer portion 35 of the spacer 33 may be spaced at a distance from the extractor electrode 27 of the extractor arrangement 25. The spacer 36 may have a radially outer portion 35 fixed only to the suppressor 24. The radially outer portion 35 of the spacer 36 is spaced at a distance from the anode 26.

[0090] like Figure 7 As shown, for example, in one embodiment, the edge profile has a path length on the surface of the edge that is greater than the thickness of the spacers 33, 36. By providing the edge profile, the possibility of unwanted electrical breakdown occurring between the spaced-out electro-optical plate elements can be reduced.

[0091] like Figure 7 As shown, in one embodiment, the edge profile includes a step. The step provides an abrupt change in the dimensions of the spacers 33, 36 in the cross-source path direction. However, a stepped edge profile is not mandatory. In an alternative embodiment, the edge profile may include a gradual change in the dimensions of the spacers 33, 36 in the cross-source path direction. By providing a stepped edge profile, the spacers 33, 36 can have stepped edges.

[0092] In an embodiment, the electro-optics module 200 includes an actuator arrangement. The actuator arrangement is configured to individually adjust the position of the emitter 21 relative to the suppressor 24 and / or the extractor arrangement 25. By individually adjusting the position of the emitter 21 relative to the extractor arrangement 25, the effect of the extractor arrangement 25 on the source beam emitted by the emitter 21 is individually controlled. Embodiments of the invention are intended to improve individuality, through which the source beam can be controlled.

[0093] In an embodiment, the actuator arrangement is configured to individually adjust the position of the transmitter 21 relative to the extractor arrangement 25 in directions along the respective source paths. For example, the actuator arrangement may be configured to adjust the position of the transmitter 21 in upstream and downstream directions. Figure 4 The transmitter 21 is adjusted in the up / down direction in the orientation shown. By adjusting the position of the transmitter 21 along the direction of the source path, the distance between the tip 22 of the transmitter 21 and the extractor arrangement 25 can be adjusted. By adjusting this distance, the characteristics of the source beam can be controlled more precisely.

[0094] Alternatively or additionally, in embodiments, the actuator arrangement is configured to adjust the local shaping of the extractor arrangement 25. For example, the actuator arrangement may be configured to apply force to one or more locations of the extractor arrangement 25 to control the shape of the extractor arrangement 25 relative to the position of the transmitter 21.

[0095] In an embodiment, the actuator arrangement is configured to individually move the emitter 21 relative to a reference frame of at least another feature of the electro-optics module 200. For example, the actuator arrangement may be configured to individually move the emitter 21 relative to the position of the suppressor 24, the position of the anode, the position of the extractor arrangement 25, the position of the extractor electrode 27 of the extractor arrangement 25, the position of the frame of the electro-optics module 200, or the position of another emitter 21. In an embodiment, at least another feature includes at least one other emitter among the emitters 21. In an embodiment, at least another feature includes at least one electro-optical plate element among electro-optical plate elements 24 to 26.

[0096] In one embodiment, the extractor arrangement 25 includes an extractor electrode 27 shared by multiple source beams. For example, Figure 4 or Figure 6 The extractor electrodes 27 shown can, for example, be adjacent to each other to form a single integral plate. The resulting extractor electrodes can be shared by multiple source beams. By providing extractor electrodes 27 shared by multiple source beams to the extractor arrangement 25, the total number of components in the electro-optics module 200 can be reduced. The construction of the electro-optics module 27 can be simplified.

[0097] In one embodiment, the extractor arrangement 25 includes a plurality of extractor electrodes 27, each extractor electrode 27 being configured to operate on a selection of a plurality of source beams. For example, each extractor electrode may be configured to operate on different plurality of source beams. In another embodiment, the extractor electrodes 27 are configured to operate on a corresponding source beam. For example, the extractor electrodes may be configured to operate on different individual source beams. The extractor electrodes 27 may be individually controlled. For example, the controller 150 may be configured to control one or more power supplies to individually control the potential applied to each extractor electrode 27. The potentials supplied to the different extractor electrodes 27 may be controlled independently of each other.

[0098] like Figure 4 , Figure 6 and Figure 7 As shown, in one embodiment, a vent 46 is defined within one or more of the electro-optical elements 24 to 26. The vent 46 is separate from the beam aperture 266 defined in the electro-optical elements 24 to 26. In another embodiment, a plurality of vents 46 are defined within one or more of the electro-optical elements 24 to 26.

[0099] like Figure 6 As shown, in this embodiment, the vents 46, defined in different electro-optical plate elements 24 to 26, can be aligned with each other, for example, in the direction along the source path. For example, the one shown closest to... Figure 6 The three vents 46 at the center of the stack 23 shown are aligned along the direction of the source path in both the suppressor 24 and the anode 26. In an embodiment, vents 46 extending only through a portion of one or more of the stack 23 are provided. For example, as Figure 7 As shown, the vent 46, located on the right side of the attached figure, is confined within the suppressor 24, but is not aligned with the corresponding vent in the anode 26. The vent may be referred to as a vent hole.

[0100] In an embodiment, the vent 46 is configured to provide gas conduction through the electro-optical plate elements 24 to 26. It is not necessary for each electro-optical plate element to have at least one vent defined therein. For example, as... Figure 7 As shown, in this embodiment, the extractor arrangement 25 does not have a vent defined therein. The extractor arrangement 25 may have a beam aperture 266 defined therein. In this embodiment, the beam aperture 266 is defined as the only aperture or hole in the extractor electrode 27 of the extractor arrangement 25. By providing a vent, gas conduction through the stack 23 can be increased. The beam aperture 266 can provide some gas conduction by providing a vent, which can increase gas conduction compared to if only the beam aperture 266 were provided for gas conduction.

[0101] In one embodiment, gas conduction is used to maintain a vacuum within the electro-optics module 200. For example, in one embodiment, the pressure within the electro-optics module 200 is maintained at a lower level than the pressure in one or more spaces within the electro-optics device 140 outside the electro-optics module 200. Increased gas conduction through the stack 23 is desirable to maintain the low pressure.

[0102] Figure 8 A portion of the electro-optical device 140 is schematically depicted. (As shown) Figure 8 As shown, in one embodiment, the stack 23 of the electron optics module 200 and the emitter 21 are positioned within a vacuum chamber 60. In one embodiment, a vacuum device 61 is configured to maintain a vacuum for the emitter 21. In one embodiment, the vacuum device 61 includes an ion pump. In one embodiment, the vacuum device includes one or more getter devices. In one embodiment, the vacuum device 61 is configured to receive gas from the space including the emitter 21. The vacuum device 61 may be configured to prevent gas backflow into the emitter 21. In one embodiment, a magnetic shield 62 is disposed between the vacuum device 61 and the emitter 21.

[0103] like Figure 8 As shown, in one embodiment, the electro-optical device 230 may include electro-optical elements downstream of the source 201. For example, in one embodiment, one or more deflector arrays 235 and / or one or more collimator arrays 260 may be positioned downstream of the source 201. In one embodiment, the electro-optical elements are positioned in a space different from the space where the source 201 is located. In one embodiment, the different spaces are maintained at different pressures. In one embodiment, the electro-optical elements define the boundary between the two different spaces maintained at different pressures.

[0104] For example, in one embodiment, a source 201, including emitter 21 and stack 23, is positioned in a space maintained under vacuum pressure. In another embodiment, a converging array 231 defines a downstream boundary of the space including source 201. In yet another embodiment, the space immediately downstream of the converging array 231 may be maintained at a different pressure. The converging array 231 may define an upstream boundary of the space. Figure 8 As shown, in an embodiment, vacuum pump 63 and / or valve (e.g., rotary valve) define the downstream end of the space.

[0105] In one embodiment, valve 64 defines the upstream boundary of a space including deflector array 235. The downstream end of this space may be defined by collimator array 260. The space including deflector array 235 can be maintained at different pressures independently of other spaces. In another embodiment, collimator array 260 defines the upstream end of another space. The downstream end of this space may be defined by objective lens array 234 and / or detector 240. This space can be maintained at different pressures independently of other spaces.

[0106] like Figure 4 As shown, in one embodiment, the electro-optics module 200 includes a converging array 231. In this embodiment, the converging array 231 is configured for each emitter 21. The converging array 231 can be considered part of the electro-optics module 200. For example, during assembly of the electro-optics module 200, the converging array 231 can be fixed to the stack 23 of the electro-optics module 200. Before the electro-optics module 200 is incorporated into the electro-optics device 230 or the electro-optics apparatus 140, the converging array 231 can be fixed relative to the emitter 21. Alternatively, the converging array 231 can be omitted from the electro-optics module 200. After the electro-optics module 200 has been incorporated into the electro-optics device 230 or the electro-optics apparatus 140, the converging array 231 of the electro-optics device 230 can be fixed relative to the emitter 21.

[0107] like Figure 4 As shown, in one embodiment, the electro-optics module 200 includes a converging frame 32. The converging frame 32 is configured to secure the converging array 231 to the stack 23. In another embodiment, multiple converging frames 32 are provided for securing a respective converging array 231 to a respective emitter 21.

[0108] like Figure 4 As shown, in this embodiment, the convergent array 231 is fixed to the downstream element of the stack 23. For example, as Figure 4 As shown, in this embodiment, the downstream element of the stack 23 is the anode 26. In this embodiment, the converging frame 32 is configured to secure the anode 26 to the converging array 231. For example, the converging frame 32 may be directly secured to both the anode 26 and the converging array 231. The converging frame 32 is configured to fix the position of the converging array 231 relative to the stack 23.

[0109] like Figure 4As shown, in this embodiment, the electron optics module 200 includes one or more electron absorbers 41, 42. For example, electron absorber 41 may be disposed on the surface of anode 26. For example, electron absorber 41 may be disposed on the upstream surface of anode 26. In this embodiment, electron absorber 42 is disposed on the surface of extractor arrangement 25. For example, electron absorber 42 may be positioned on the downstream surface of extractor arrangement 25.

[0110] like Figure 4 As shown, in this embodiment, an electron absorber 41 is disposed at the anode 26 corresponding to each emitter 21. An electron absorber 42 may be disposed at the extractor arrangement 25 of each emitter 21. In this embodiment, when viewed in a plan view (i.e., along the source path), the electron absorbers 41, 42 are formed to substantially surround the source path. For example, the electron absorbers 41, 42 may form a ring.

[0111] In one embodiment, one or more electron absorbers are disposed on the upstream surface of the extractor arrangement. In another embodiment, one or more electron absorbers are positioned on the downstream surface of the suppressor 24.

[0112] In this embodiment, electron absorbers 41 and 42 are configured to reduce the electron flow radially outward from the source path. It is not necessary for electron absorbers 41 and 42 to be formed in a ring shape. In alternative arrangements, electron absorbers 41 and 42 may include multiple arcuate or elongated portions when viewed in a planar view (i.e., along the beam path).

[0113] like Figure 4 As shown, in this embodiment, the recess 49 can be provided on the surface facing (or opposite) the electron absorbers 41, 42. For example, the recess 49 is provided in the downstream surface of the extractor arrangement 25 opposite to the electron absorber 41. Similarly, the recess 49 is provided on the upstream surface of the anode 26, opposite to the electron absorber 42 which is provided on the downstream surface of the extractor arrangement 25. By providing the recess, the size of the gap between adjacent electron optical plate elements can be made more consistent in the direction of the beam path. By making the gap size more consistent, the electric field amplitude can be more consistent. Undesirable peaks in the electromagnetic field amplitude can be reduced. By avoiding high peaks in the electromagnetic field amplitude, the possibility of undesirable electrical breakdown can be reduced.

[0114] By reducing the radial outward flow of electrons from the source path, the likelihood of unwanted charging of components in the source module 200 can be reduced. For example, the likelihood of unwanted charging of spacers 33 and 36 can be reduced. By reducing the charging of components with spacers 33 and 36, the possibility of unwanted electrical breakdown can be reduced.

[0115] like Figure 4 As shown, for example, in an embodiment, the elements of the electro-optical module 200 are aligned. For example, the elements of the electro-optical module 200 may be aligned prior to assembly. Alignment may be performed before the electro-optical module 200 is incorporated into the electro-optical device 230 or the electro-optical apparatus 140. Further alignment may be performed to align the electro-optical module 200 with respect to other electro-optical elements of the electro-optical apparatus 140 or the electro-optical device 230.

[0116] Embodiments of the present invention may be methods for providing a source beam for a plurality of electro-optical devices 230. The method may include individually adjusting the position of the emitter 21 relative to the extractor arrangement 25. For example, the partial shape of the extractor arrangement 25 may be adjusted. Additionally or alternatively, the extractor arrangement 25 may be shaped under thermal load during operation. Under thermal load applied during operation, the extractor electrodes 27 included in the extractor arrangement 25 may be individually operated on the source beam.

[0117] In an embodiment, the elements of stack 23 can be aligned relative to the emitter 21 of the electro-optics module 200. After the elements of stack 23 have been aligned relative to the emitter 21, the elements of stack 23 can be fixed to each other, and stack 23 can be fixed to emitter 21. For example, each pair of adjacent elements of stack 23 can be aligned relative to each other. For example, electro-optics plate elements can be adjacent along the source path of the source beam from emitter 21. Spacers can be adjacent along the source path of the source beam. Spacers and adjacent electro-optics plate elements can be adjacent along the source path of the source beam. The positions of different pairs of adjacent elements can be fixed. For example, when the adjacent element is adjacent to a spacer, then the adjacent element can be fixed by fixing interlaced electro-optics plate elements to adjacent spacers. For example, Figure 4 The two different types of spacers 33 and 35 shown can be fixed to each other by fixing spacers 33 and 35 to the suppressor 24.

[0118] When the adjacent elements are adjacent electro-optical plate elements, the interlaced spacers between the adjacent electro-optical plate elements can be fixed to the adjacent electro-optical plate elements. For example, spacer 33 can be fixed between suppressor 24 and extractor arrangement 25, thereby fixing suppressor 24 to extractor arrangement 25. Spacer 36 can be fixed to anode 26 and fixed to suppressor 24, thereby fixing suppressor 24 to anode 26.

[0119] In an embodiment, the transmitter 21 is fixed to the stack 23 by fixing the transmitter 21 to the upstream electro-optical plate element of the stack 23. For example, in Figure 4In the arrangement shown, the upstream electro-optical element of the stack 23 is the suppressor 24. The emitter 21 can be fixed to the stack 23 by fixing the emitter 21 to the suppressor. For example, as Figure 4 As shown, in one embodiment, the electro-optics module 200 includes an emitter frame 31. The emitter frame 31 is configured to secure the emitter 21 to a stack 23 of the electro-optics module 200. The emitter frame 31 may include one or more rigid members secured to both the emitter 21 and the stack 23. By configuring the emitter frame 31, the position of the emitter 21 relative to the stack 23 can be reliably and precisely secured. In one embodiment, the emitter frame 31 is secured to a suppressor 24.

[0120] In this embodiment, the transmitters 21 are positioned relative to each other in a reference frame. As an example, the alignment of the elements of the stack 23 may be relative to a reference frame. Electro-optical plate elements 24 to 26 may be aligned relative to each other. Electro-optical plate elements 24 to 26 may be aligned relative to the transmitters 21.

[0121] In an embodiment, at least one of the electron optical elements 24 to 26, spacers 33 and 36, and beam aperture 266 of the various electron optical elements 24 to 26 are aligned with a reference frame relative to at least one of the transmitters 21. This reference frame may be the reference frame of a single transmitter 21, which may be referred to as a reference transmitter. Alternatively, the reference frame may be the reference frame of multiple transmitters 21. For example, the reference frame may be the reference frame of all transmitters 21.

[0122] In an embodiment, at least one of the electro-optical plate elements 24 to 26, spacers 33 and 36, and beam aperture 266 in the different electro-optical plate elements 24 to 26 are aligned with the source path of the source beam of at least one different emitter 21. The source path can be used as a reference for the alignment of other components of the electro-optical module 200.

[0123] In an embodiment, at least one of the electron optical plate elements 24 to 26, spacers 33 and 36, and beam aperture 266 of the different electron optical plate elements 24 to 26 are aligned with at least the transmitter 21.

[0124] In this embodiment, the beam aperture 266 of the different electro-optical plate elements 24 to 26 is aligned relative to the transmitter 21. For example, as Figure 4 As shown, the beam aperture 266 is positioned downstream of the transmitter 21. The beam aperture 266 can be aligned in the direction along the source path.

[0125] like Figure 3As shown, in this embodiment, the plurality of electro-optical devices 230 may include an electro-optical module 200. The electro-optical module may be configured to generate a source beam for the electro-optical devices 230.

[0126] In an embodiment, each electro-optical device 230 includes an electro-optical element downstream of the electro-optical module 230. The electro-optical element of the electro-optical device 230 can be configured to operate on a source beam. The electro-optical element can be configured to operate on a primary beam derived from the source beam generated by the electro-optical module 200.

[0127] In one embodiment, the electro-optical elements of the electro-optical device 230 are configured to operate on a corresponding source beam or a primary beam derived from a corresponding source beam. Alternatively, the electro-optical elements may be configured to operate on multiple source beams or primary beams derived from multiple source beams. Each electro-optical device 230 may have a source 201. Alternatively, each electro-optical device 230 may have multiple sources 201. Alternatively, the primary beams of multiple electro-optical devices 230 may be derived from the source beam of a single source 201. The source 201 may be included in the same electro-optical module 200.

[0128] In an embodiment, the evaluation apparatus 100 includes an electro-optical device 140. The electro-optical device 140 may include a plurality of electro-optical devices 230. Each electro-optical device 230 may include at least one detector 240. When the sample 208 is supported at the sample location, the detector 240 may be configured to detect signal particles from the sample 208. In an embodiment, at least one detector 240 includes one or more electro-optical plate elements. The detector interacts with electrons, allowing it to be considered an electro-optical element.

[0129] The following numbered clauses describe further embodiments of the invention: 1. A charged particle optical module for use with multiple charged particle optical devices configured to guide a charged particle beam toward a sample location along a corresponding beam path, the charged particle optical module comprising: Multiple emitters, configured to emit respective source beams of charged particles along corresponding source paths; and Multiple charged particle optical plate elements are configured to operate on a source beam, and multiple beam apertures configured for the passage of the source beam are defined in the multiple charged particle optical plate elements, wherein at least one charged particle optical plate element is shared by multiple emitters. The charged particle optical plate element includes an extractor arrangement configured to operate the source beam individually. 2. The charged particle optical module according to Clause 1, comprising: Multiple spacers are configured to space multiple charged particle optical plate elements apart from each other. 3. The charged particle optical module according to Clause 2, wherein the spacers are configured to mechanically support charged particle optical plate elements that are opposite each other. 4. The charged particle optical module according to Clause 2 or Clause 3, wherein the spacers are configured to electrically isolate the charged particle optical plate elements from each other. 5. The charged particle optical module according to any one of clauses 2 to 4, wherein the spacer is configured to mechanically support an extractor arrangement positioned individually relative to the beam path of the source beam, such that the extractor arrangement is configured to operate the source beam individually. 6. The charged particle optical module according to Clause 5, wherein the spacer is configured to shape the extractor under thermal load during operation. 7. The charged particle optical module according to Clause 6, wherein the spacer is positioned relative to at least some of the extractor electrodes included in the extractor arrangement such that, under thermal loads applied during operation, the extractor electrodes included in the extractor arrangement operate individually on the source beam. 8. The charged particle optical module according to Clause 7, comprising extractor electrodes in an extractor arrangement that operate individually on the source beam such that thermal expansion of the extractor electrodes and / or spacers included in the extractor arrangement causes a corresponding movement of the respective position of the extractor electrodes included in the extractor arrangement relative to the source path of the source beam. 9. The charged particle optical module according to any one of clauses 2 to 8, wherein the spacer is configured as a mechanically supported extractor arrangement. 10. The charged particle optical module according to Clause 9, wherein for each source beam, a plurality of spacers are configured as a mechanically supported extractor arrangement. 11. The charged particle optical module according to Clause 10, wherein the extractor arrangement includes a plurality of extractor electrodes. 12. The charged particle optical module according to Clause 11, wherein each extractor electrode is configured to operate on a different source beam. 13. The charged particle optical module according to Clause 12, wherein each extractor electrode is configured to operate separately on different source beams. 14. The charged particle optical module as described in Clause 13, wherein each extractor electrode has multiple spacers. 15. The charged particle optical module according to Clause 14, wherein each extractor electrode has three spacers. 16. The charged particle optical module according to any one of Clauses 2 to 15, wherein the spacers are substantially planar. 17. The charged particle optical module according to Clause 16, wherein the spacer is substantially parallel to one or more charged particle optical plate elements. 18. A charged particle optical module according to any one of clauses 2 to 17, wherein the spacers have substantially similar shapes in at least two dimensions. 19. The charged particle optical module according to Clause 18, wherein the spacers have substantially similar shapes in cross-section. 20. The charged particle optical module according to Clause 18 or 19, wherein the spacers are substantially the same in size in the cross-source path direction. 21. The charged particle optical module according to any one of clauses 2 to 20, wherein the spacer is substantially disk-shaped. 22. The charged particle optical module according to any one of clauses 2 to 21, wherein the spacer has an edge profile. 23. The charged particle optical module according to Clause 22, wherein the edge profile has a path length on the surface of the edge that is greater than the thickness of the spacer. 24. The charged particle optical module according to clause 22 or 23, wherein the edge profile includes steps. 25. The charged particle optical module as described in Clause 24, wherein the spacer has stepped edges. 26. The charged particle optical module according to any of the preceding clauses, comprising: The actuator arrangement is configured to individually adjust the relative position of the transmitter to the extractor arrangement. 27. The charged particle optical module according to Clause 26, wherein the actuator arrangement is configured to individually adjust the relative position of the emitter to the extractor arrangement along the direction of the respective source path. 28. The charged particle optical module according to clause 26 or 27, wherein the actuator arrangement is configured to adjust the local shaping of the extractor arrangement. 29. A charged particle optical module according to any one of clauses 26 to 28, wherein the actuator arrangement is configured to move the emitter individually relative to a reference frame of at least another feature of the charged particle optical module. 30. The charged particle optical module according to Clause 29, wherein at least another feature includes at least one other emitter in the emitter. 31. The charged particle optical module according to clause 29 or 30, wherein at least another feature includes at least one charged particle optical plate element among the charged particle optical plate elements. 32. The charged particle optical module described in any of the preceding clauses, wherein the extractor arrangement includes extractor electrodes shared by multiple source beams. 33. The charged particle optical module described in any of the preceding clauses, wherein the extractor arrangement includes a plurality of extractor electrodes, each extractor electrode being configured to operate on a selection of a plurality of source beams. 34. The charged particle optical module according to Clause 33, wherein the extractor electrode is configured to operate on the corresponding source beam. 35. The charged particle optical module according to clause 33 or 34, wherein the extractor electrode is individually controllable. 36. The charged particle optical module described in any of the preceding clauses, wherein the vent is defined in one or more of the charged particle optical plate elements. 37. The charged particle optical module according to Clause 36, wherein the vent is configured to provide gas conduction through the charged particle optical plate element. 38. The charged particle optical module as described in Clause 37, wherein gas conduction is used to maintain a vacuum within the charged particle optical module. 39. The charged particle optical module described in any of the preceding clauses, wherein the elements of the charged particle optical module are aligned. 40. The charged particle optical module as described in Clause 39, wherein the elements of the charged particle optical module are aligned prior to assembly. 41. The charged particle optical module according to clause 39 or 40, wherein at least one of the charged particle optical plate elements, spacers, and beam apertures of the different charged particle optical plate elements is aligned with a reference frame of at least one of the emitters. 42. A charged particle optical module according to any of the provisions 39 to 41, wherein at least one of the charged particle optical plate elements, spacers, and beam apertures of different charged particle optical plate elements is aligned with the source path of the source beams of at least different emitters. 43. A charged particle optical module according to any of the provisions 39 to 42, wherein at least one of the charged particle optical plate elements, spacers, and beam apertures of the different charged particle optical plate elements is aligned with at least the emitter. 44. A charged particle optical module according to any of the clauses 39 to 43, wherein the beam apertures of the different charged particle optical plate elements are aligned with respect to the emitter. 45. The charged particle optical module according to any of the preceding clauses, wherein at least one charged particle optical plate element is planar. 46. ​​The charged particle optical module as described in Clause 45, wherein all charged particle optical plate elements are planar. 47. A plurality of charged particle optical devices are configured to guide a charged particle beam to a sample location along a respective beam path, the plurality of charged particle optical devices including the charged particle optical module described in any of the preceding clauses. 48. The plurality of charged particle optical devices as described in Clause 47, wherein each charged particle optical device includes a charged particle optical element downstream of a charged particle optical module, configured to operate on a source beam or on a primary beam derived from the source beam. 49. A plurality of charged particle optical devices according to clause 47 or 48, wherein the charged particle optical elements are configured to operate on a respective source beam or a primary beam derived from a respective source beam, or to operate on a plurality of source beams or primary beams derived from a plurality of source beams. 50. A charged particle optical device, comprising: Multiple charged particle optical devices as described in any of Clauses 47 to 49; and An actuable stage is configured to support the sample at the sample location. 51. The charged particle optical device according to Clause 50, further comprising: It includes a vacuum chamber containing multiple charged particle optical devices and an actuable stage. 52. An evaluation apparatus for evaluating a sample, comprising charged particle optical devices as described in Clause 50 or Clause 51, wherein a plurality of charged particle optical devices include at least one detector configured to detect signal particles from the sample when supported in the sample position. 53. The evaluation apparatus according to Clause 52, wherein at least one detector comprises one or more charged particle optical plate elements. 54. A method for providing a source beam for a plurality of charged particle optical devices configured to guide a charged particle beam to a sample location along a respective beam path, the method comprising: A corresponding source beam of charged particles is emitted from multiple emitters along corresponding source paths; and A source beam is operated using multiple charged particle optical plate elements, wherein multiple beam apertures configured for the passage of the source beam are defined within the multiple charged particle optical plate elements, wherein at least one of the charged particle optical plate elements is shared by multiple emitters. The operation includes: using the extractor arrangement of charged particle optical plate elements to operate the source beam individually. 55. The method described under Clause 54, comprising: Adjust the relative position of the transmitter to the extractor individually. 56. The method according to Clause 55, wherein the adjustment includes adjusting the local shaping of the extractor arrangement. 57. The method according to any one of clauses 54 to 56, comprising: shaping the extractor arrangement under thermal load during operation. 58. The method according to Clause 57, wherein, under thermal load applied during operation, the extractor electrodes included in the extractor arrangement operate the source beam individually. 59. The method according to Clause 58, comprising extractor electrodes in an extractor arrangement operating individually on a source beam such that thermal expansion of the extractor electrodes included in the extractor arrangement causes a corresponding movement of a respective position of the extractor electrodes included in the extractor arrangement relative to the source path of the source beam. 60. The method described pursuant to any of Clauses 54 to 59, comprising: Each of the multiple extractor electrodes is arranged separately to operate on different source beams. 61. A method for assembling a charged particle optical module for a charged particle optical device configured to guide a charged particle beam along a respective beam path toward a sample location, the charged particle optical module comprising: Multiple transmitters used to emit a source beam. Multiple charged particle optical plate elements for manipulating charged particles emitted by the transmitter, and Spacers interlaced between adjacent charged particle optical plate elements serve to support and electrically isolate the charged particle optical plate elements. The method includes spacers and charged particle optical plate elements in a stack, comprising: Align the stacked components relative to the transmitter, and The stacked components are fixed to each other, and the stack is fixed to the transmitter. 62. The method according to Clause 61, wherein alignment comprises: applying a stack of adjacent elements to each pair of adjacent elements. 63. The method according to clause 62, wherein the elements of the adjacent element pair include: Adjacent charged particle optical plate elements along the source path of the source beam from the emitter. Adjacent spacers along the source path of the source bundle, and / or Adjacent spacers and adjacent charged particle optical plate elements along the source path of the source beam. 64. The method described under any of clauses 61 to 63, wherein fixing includes fixing the positions of different adjacent element pairs. 65. The method according to Clause 64, wherein when the adjacent element is an adjacent spacer, fixing the adjacent element includes fixing the interlaced charged particle optical plate elements to the adjacent spacer. 66. The method according to clause 64 or 65, wherein when the adjacent element is an adjacent charged particle optical plate element, fixing includes fixing interlaced spacers between adjacent charged particle optical plate elements to the adjacent charged particle optical plate elements. 67. The method according to any one of clauses 61 to 66, wherein securing the emitter to the stack includes securing the emitter to the most upstream charged particle optical plate element of the stack. 68. The method according to any one of clauses 61 to 67, wherein the transmitters are positioned in a reference frame relative to each other. 69. The method according to Clause 68, wherein the alignment of the stacked elements is relative to a reference frame. 70. A multi-source module for a multi-column electron beam system, the module comprising: Multiple emitters configured to emit corresponding electron beams, and Multiple plate electrodes configured to operate the source beam. Multiple beam apertures confined in different plate electrodes, and Two or more plate electrodes are shared by more than one transmitter in the transmitter. 71. The multi-source module according to Clause 70, wherein multiple plate electrodes include extractor layers configured to operate individually for different source beams. 72. The multi-source module according to Clause 70 or Clause 71 further includes spacers configured to support and isolate the plate electrodes. 73. The multi-source module according to Clause 72, wherein the spacers are configured to have corresponding positions relative to the beam path, which allows the extractor layer to be locally shaped to operate on different source beams individually. 74. The multi-source module according to Clause 72 or Clause 73, wherein the position of the spacer is configured to cause the extractor layer to be formed under thermal load during operation. 75. The multi-source module according to Clause 73 or Clause 74 further includes an actuator configured to actuate local shaping of the extractor. 76. In the multi-source module described in any of Clauses 72 to 75, the spacer is planar, disk-shaped, and / or has stepped edges. 77. A multi-source module according to any of clauses 70 to 76, wherein the extractor layer includes extractor electrodes shared by multiple source beams. 78. A multi-source module according to any of clauses 70 to 77, wherein the extractor layer includes different extractor electrodes for different source beams. 79. The multi-source module as described in Clause 78, wherein the different extractor electrodes are independently controllable. 80. A multi-source module according to Clause 78 or Clause 79, wherein the spacers are positioned relative to the beam path on the extractor layer, and preferably at least three spacers support the respective extractor electrodes. 81. A multi-source module according to any of the provisions 70 to 80, wherein a vent is defined in one or more planar electrodes, the vent being configured to provide conduction through a stack comprising a plurality of electrode plates for maintaining a vacuum within the multi-source module.

[0130] Although embodiments of the invention may be specifically referenced herein in the context of electron microscopy, embodiments of the invention can be used in other types of apparatuses. Embodiments of the invention may form part of a mask inspection apparatus, a measurement apparatus, or any apparatus for measuring or processing a target such as a wafer (or other substrate) or a mask (or other patterning apparatus).

[0131] Although specific embodiments of the invention have been described above, it should be understood that the invention may be practiced in ways other than those described. The above description is intended to be illustrative and not limiting. Therefore, it will be apparent to those skilled in the art that modifications may be made to the described invention without departing from the scope of the claims set forth below.

Claims

1. A multi-source module for a multi-column electron beam system, the module comprising: Multiple transmitters, the multiple transmitters being configured to emit source beams of corresponding electrons; as well as Multiple plate electrodes are configured to operate the source beam. Multiple beam apertures, wherein the multiple beam apertures are defined in different plate electrodes, and Two or more of the plate electrodes are shared by more than one of the transmitters.

2. The multi-source module of claim 1, wherein the plurality of plate electrodes includes an extractor layer configured to operate individually on different source beams.

3. The multi-source module according to claim 1 or 2 further includes a spacer configured to support and isolate the plate electrodes.

4. The multi-source module of claim 3, wherein the spacer is configured to have a corresponding position relative to the beam path, the spacer enabling the extractor layer to be locally shaped for individual operation of different source beams.

5. The multi-source module according to claim 3 or 4, wherein the position of the spacer is configured to shape the extractor layer under thermal load during operation.

6. The multi-source module according to claim 4 or 5 further includes an actuator configured to actuate local shaping of the extractor.

7. The multi-source module according to any one of claims 3 to 6, wherein the spacer is planar, disk-shaped, and / or has stepped edges.

8. The multi-source module according to any one of claims 1 to 7, wherein the extractor layer includes an extractor electrode shared by the plurality of source beams.

9. The multi-source module according to any one of claims 1 to 8, wherein the extractor layer comprises different extractor electrodes for different source beams.

10. The multi-source module according to claim 9, wherein the different extractor electrodes are independently controllable.

11. The multi-source module of claim 9 or 10, wherein the spacers are positioned relative to the beam path on the extractor layer, and preferably at least three spacers support the respective extractor electrodes.

12. The multi-source module according to any one of claims 1 to 11, wherein a vent is defined in one or more planar electrodes, the vent being configured to provide conduction through a stack comprising a plurality of electrode plates, the conduction being used to maintain a vacuum within the multi-source module.

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