Charged particle system and method of baking out a charged particle system

Abstract

The present disclosure relates to a charged particle system for emitting a charged particle beam towards a sample to inspect the sample. The system comprises a source, a charged particle device, a support, a vacuum system, and a thermal control system. The source is configured to emit a charged particle beam. The charged particle device is configured to project the charged particle beam towards a sample. The charged particle device comprises a plurality of charged particle optical elements along the path of the charged particle beam. The support is configured to support the sample. The vacuum system comprises a plurality of chambers, wherein different chambers are configured to comprise at least one respective component. The at least one respective component comprises at least one of the source and one or more charged particle optical elements. The thermal control system is configured to independently bake out the different chambers.

Description

Cross-reference to related applications

[0001] This application claims priority to U.S. Application 63 / 547,971, filed November 9, 2023, and European Application 23218424.2, filed December 20, 2023, both of which are incorporated herein by reference in their entirety. Technical Field

[0002] The embodiments provided herein generally relate to a system, related apparatus, and method for guiding charged particles (such as electrons) toward a sample. Background Technology

[0003] In the manufacture of semiconductor integrated circuit (IC) chips, unwanted pattern defects may occur on the substrate (e.g., wafer) or mask during the fabrication process, thereby reducing yield. These defects may occur due to, for example, optical effects and stray particles, or other processing steps such as etching, deposition, or chemical mechanical polishing. Therefore, monitoring the extent of unwanted pattern defects is a crucial process in IC chip manufacturing. More generally, the evaluation (e.g., inspection and / or measurement) of the substrate surface or other objects / materials is an important process during and / or after manufacturing.

[0004] Pattern evaluation systems (such as pattern inspection tools using beams of charged particles) have been used to evaluate objects, for example, to detect pattern defects. The charged particles are typically electrons. These systems often utilize electron microscopy techniques, such as scanning electron microscopy (SEM). In SEM, a primary electron beam, containing electrons at relatively high energies, is guided by a final deceleration step to land on the target at a relatively low landing energy. The electron beam is focused onto the target as a probe spot. The interaction between the material structure at the probe spot and the landing electrons from the electron beam causes electrons to be emitted from the surface, such as secondary electrons, backscattered electrons, or Auger electrons, which can be collectively referred to as signal electrons or, more generally, signal particles. The generated secondary electrons can be emitted from the material structure of the target.

[0005] By scanning the target surface as a probe spot with a primary electron beam, signal electrons can be emitted from the target surface. By collecting these emitted signal electrons from the target surface, the pattern inspection tool (or device) can obtain an image-like signal representing the material structure properties of the target surface.

[0006] Due to the small size and special materials of some components, evaluation systems like this one can be sensitive to contamination-induced failures. One way to reduce contamination levels is to bake the degassing system by heating the components to high temperatures to increase the evaporation rate of the contaminants. This can result in significant downtime during the baking process to remove the contaminants and restore the evaluation system to a sufficient performance level. During this downtime, sample evaluations cannot be performed using the evaluation system. Summary of the Invention

[0007] The purpose of this disclosure is to provide a system and method for reducing pollution in a time-efficient manner.

[0008] According to one aspect of the invention, a charged particle system is provided for emitting a charged particle beam toward a sample to examine the sample. The system includes: a source, a charged particle device, a support, a vacuum system, and a thermal control system. The source is configured to emit the charged particle beam. The charged particle device is configured to project the charged particle beam toward the sample. The charged particle device includes a plurality of charged particle optical elements along the path of the charged particle beam. The support is configured to support the sample. The vacuum system includes a plurality of chambers, wherein different chambers are configured to include at least one corresponding component. At least one corresponding component includes the source and at least one of one or more charged particle optical elements. The thermal control system is configured to independently bake and degas the different chambers.

[0009] According to one aspect of the invention, a method for baking and degassing a charged particle system is provided. The charged particle system includes: a source configured to emit a beam of charged particles; a charged particle device configured to project the beam of charged particles toward a sample, the charged particle device including a plurality of charged particle optical elements along the path of the charged particle beam; a vacuum system having a plurality of chambers, wherein each chamber includes at least one corresponding component, the at least one corresponding component including the source and at least one of one or more charged particle optical elements; and a thermal control system configured to bake and degas the different chambers. The method includes controlling the thermal control system to independently bake and degas the different chambers.

[0010] The advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which certain embodiments of the invention are illustrated and exemplified. Attached Figure Description

[0011] The above and other aspects of this disclosure will become more apparent from the description of exemplary embodiments in conjunction with the accompanying drawings.

[0012] Figure 1 This is a schematic diagram illustrating an exemplary evaluation device.

[0013] Figure 2 It is illustrated as Figure 1 A schematic diagram of an exemplary multi-beam charged particle evaluation system, which is part of an exemplary electron beam evaluation device.

[0014] Figure 3 It is a schematic diagram of a charged particle system including a thermal control system.

[0015] Figure 4 The diagram illustrates a charged particle system including a thermal control system comprising heaters disposed in the walls of multiple chambers.

[0016] Figure 5 This is a schematic diagram of an exemplary electro-optical system including a macro-collimator and a macro-scan deflector.

[0017] Figure 6 It is illustrated as Figure 1 A schematic diagram of an exemplary multi-beam charged particle optical device, which is a part of an exemplary evaluation device.

[0018] Figure 7 Is as Figure 1 A schematic diagram of an alternative exemplary multi-beam charged particle optical device, which is a part of an exemplary evaluation device.

[0019] Figure 8 This is a schematic diagram of an exemplary multi-beam charged particle device.

[0020] Figure 9 This is a schematic diagram of an exemplary array of charged particle optical devices, including multiple charged particle optical devices.

[0021] Figure 10 It is a schematic diagram of a charged particle device that includes charged particle devices.

[0022] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, wherein, unless otherwise indicated, the same reference numerals in different drawings denote the same or similar elements. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the invention. Rather, they are merely examples of devices and methods consistent with various aspects of the invention as enumerated in the appended claims. Detailed Implementation

[0023] By significantly increasing the packaging density of circuit components such as transistors, capacitors, and diodes on IC chips, it is possible to reduce the physical size of devices and enhance the computing power of electronic devices. This is achieved by increasing resolution, thereby enabling the fabrication of smaller structures. Semiconductor IC manufacturing is a complex and time-consuming process with hundreds of individual steps. Errors in any step of the IC chip manufacturing process can adversely affect the operation of the final product. A single defect can cause a device malfunction. Improving the overall yield of this process is desirable. For example, to achieve a 75% yield in a 50-step process (where steps can indicate the number of layers formed on the wafer), the yield of each individual step must be greater than 99.4%. If the yield of individual steps is 95%, the overall process yield will be as low as 7% to 8%.

[0024] Maintaining high substrate (i.e., wafer) throughput (defined as the number of substrates processed per hour) is also desirable. The presence of defects can impact high process yields and high substrate throughput. This is especially true if reviewing defects requires operator intervention. Detecting and identifying micron and nanometer-scale defects at high throughput using evaluation systems such as SEM is desirable for maintaining high yields and low costs for IC chips.

[0025] A scanning electron microscope (SEM) comprises a scanning apparatus and a detector apparatus. The scanning apparatus includes an illumination apparatus comprising an electron source for generating primary electrons and a projection apparatus for scanning a target, such as a substrate, using one or more focused primary electron beams. The primary electrons interact with the target and generate interaction products, such as signal particles, like secondary electrons and / or backscattered electrons. Secondary electrons can be considered to have energies up to 50 eV. While having an energy spectrum ranging from essentially zero to the maximum energy of charged particle devices, backscattered electrons are conventionally defined as electrons (or signal electrons) with energies exceeding 50 eV. When scanning a target, the detector apparatus captures signal particles (e.g., secondary electrons and / or backscattered electrons) from the target, allowing the SEM to create an image of the scanned area of ​​the target. Charged particle optics devices implementing these features of SEM can be designed with a single beam. For higher throughput, such as for evaluation, some designs use multiple focused primary electron beams, i.e., multi-beam primary electron beams. The component beams in a multi-beam setup can be referred to as sub-beams or beam waves. Multiple beams can scan different portions of the target simultaneously. Therefore, multi-beam evaluation devices can evaluate targets faster than single-beam evaluation devices, for example, by moving the target at a higher speed.

[0026] The following describes the known implementations of multi-beam evaluation devices.

[0027] The accompanying drawings are schematic. Therefore, for clarity, the relative dimensions of the components in the drawings are exaggerated. Throughout the following description of the drawings, the same or similar reference numerals refer to the same or similar components or entities, and differences are described only with respect to the various embodiments. Although the description and drawings relate to electro-optical devices, it is to be understood that the embodiments are not intended to limit this disclosure to specific charged particles. Therefore, throughout this document, references to items referring to electrons and reference to electrons can be more generally considered as references to charged particles and references to charged particles, which are not necessarily electrons.

[0028] Now for reference Figure 1 It is a schematic diagram illustrating an exemplary evaluation device 100 (e.g., an inspection device). Figure 1 The evaluation device 100 includes a vacuum chamber 10, a load-locking chamber 20, a charged particle optical device, an equipment front-end module (EFEM) 30, and a controller 50. The charged particle device 41 may be located within the vacuum chamber 10. The electron optical device may include the charged particle device 41 (also referred to as an electron optical device, electron beam device, or electron beam apparatus) and a motorized or actuated stage.

[0029] EFEM 30 includes a first loading port 30a and a second loading port 30b. EFEM 30 may include one or more additional loading ports. The first loading port 30a and the second loading port 30b may, for example, house a front-opening substrate transfer box (FOUP) containing a substrate to be evaluated (e.g., a semiconductor substrate or a substrate made of one or more other materials) or a target (substrate, wafer, and sample are collectively referred to as the “target”). One or more robotic arms (not shown) in EFEM 30 transport the target to the loading locking chamber 20.

[0030] Loading-lock chamber 20 is used to remove gas surrounding the target. Loading-lock chamber 20 can be connected to a loading-lock vacuum pump system (not shown), which removes gas particles from the loading-lock chamber 20. Operation of the loading-lock vacuum pump system allows the loading-lock chamber to reach a first pressure below atmospheric pressure. Main chamber 10 is connected to a main chamber vacuum pump system (not shown). The main chamber vacuum pump system removes gas molecules from the main chamber 10, causing the pressure around the target to reach a second pressure below the first pressure. After reaching the second pressure, the target is transported to charged particle device 41, through which the target can be evaluated. Charged particle device 41 may include single-beam or multi-beam charged particle optics.

[0031] The controller 50 is electronically connected to the charged particle system 40. The controller 50 may be a processor (such as a computer) configured to control the charged particle beam evaluation device 100. The controller 50 may also include a processing circuitry system configured to perform various signal and image processing functions. Although the controller 50 is... Figure 1 The main chamber 10, the loading and locking chamber 20, and the EFEM 30 are shown as being outside the structure, but it should be understood that the controller 50 may be part of the structure. The controller 50 may be located in one of the components of the charged particle beam evaluation apparatus, or it may be distributed across at least two components. While this disclosure provides an example of a main chamber 10 housing an electron beam evaluation apparatus, it should be noted that the broadest aspects of this disclosure are not limited to chambers housing charged particle optics. Rather, it should be understood that the foregoing principles can also be applied to other apparatus and other apparatus arrangements operating under a second pressure.

[0032] Now for reference Figure 2 , Figure 2 This is a schematic diagram illustrating an exemplary charged particle system 40 including a multi-beam charged particle device 41, which is... Figure 1 This is part of an exemplary charged particle beam evaluation apparatus 100. The multi-beam charged particle device 41 includes an electron source 201 and a projection device 230. The charged particle system 40 also includes an actuation stage 209 and a sample holder 207. The sample holder may have a holding surface (not depicted) for supporting and holding a sample. Thus, the sample holder can be configured to support a sample. This holding surface may be an electrostatic clamp operable to hold the sample during operation of the charged particle device 41 (e.g., evaluation of at least a portion of the sample, such as measurement or inspection). The holding surface may be recessed into the sample holder, for example, the sample holder being oriented to face the surface of the charged particle device 41. The electron source 201 and the projection device 230 may be collectively referred to as the charged particle device 41. The sample holder 207 is supported by the actuation stage 209 to hold a sample 208 (e.g., a substrate or mask) for evaluation. The multi-beam charged particle device 41 also includes a detector 240 (e.g., an electronic detection device).

[0033] The electron source 201 may include a cathode (not shown) and an extractor or anode (not shown). During operation, the electron source 201 is configured to emit electrons from the cathode as primary electrons. The primary electrons are extracted or accelerated by the extractor and / or anode to form a primary electron beam 202.

[0034] Projection device 230 is configured to convert primary electron beam 202 into multiple sub-beams 211, 212, 213, and to direct each sub-beam onto sample 208. Although three sub-beams are illustrated for simplicity, there may be tens, hundreds, or thousands of sub-beams. Sub-beams may be referred to as beam waves.

[0035] Controller 50 can be connected to Figure 1 The charged particle beam evaluation device 100 comprises various components, such as an electron source 201, a detector 240, a projection device 230, and an actuation stage 209. A controller 50 can perform various image and signal processing functions. The controller 50 can also generate various control signals to manage the operation of the charged particle beam evaluation device, including multi-beam charged particle devices.

[0036] Projection device 230 can be configured to focus sub-beams 211, 212, and 213 onto sample 208 for evaluation, and can form three probe spots 221, 222, and 223 on the surface of sample 208. Projection device 230 can be configured to deflect primary sub-beams 211, 212, and 213 to scan probe spots 221, 222, and 223 across various scanning regions in a surface segment of sample 208. This scanning can be controlled by controller 50 to cooperate with simultaneous scanning movement of actuator stage 209. In response to the primary sub-beams 211, 212, and 213 incident on probe spots 221, 222, and 223 on sample 208, signal electrons comprising secondary electrons and backscattered electrons are generated from sample 208. The electron energy of the secondary electrons is typically ≤50 eV. Actual secondary electrons can have energies less than 5 eV, but anything with an energy below 50 eV is generally considered a secondary electron. The electron energies of backscattered electrons are typically between 0 eV and the landing energies of the primary sub-beams 211, 212, and 213. Since electrons with detected energies less than 50 eV are generally considered secondary electrons, a certain percentage of actual backscattered electrons will be counted as secondary electrons.

[0037] Detector 240 is configured to detect signal particles, such as secondary electrons and / or backscattered electrons, and generate corresponding signals, which are sent to signal processing system 280, for example, to construct an image of the corresponding scanned region of sample 208. Detector 240 may be incorporated into projection device 230.

[0038] The signal processing system 280 may include circuitry (not shown) configured to process signals from the detector 240 to form an image. The signal processing system 280 may also be referred to as an image processing system. The signal processing system may be incorporated into components of the multi-beam charged particle system 40, such as the detector 240 (e.g., Figure 2(As shown). However, the signal processing system 280 can be incorporated into any component of the evaluation device 100 or the multi-beam charged particle system 40, such as as part of the projection device 230 or the controller 50. The signal processing system 280 may include an image acquirer (not shown) and a storage device (not shown). For example, the signal processing system may include a processor, computer, server, mainframe, terminal, personal computer, any kind of mobile computing device, etc., or combinations thereof. The image acquirer may include at least a portion of the processing functionality of the controller. Therefore, the image acquirer may include at least one or more processors. The image acquirer may be communicatively coupled to the detector 240, which allows signal communication, such as an electrical conductor, fiber optic cable, portable storage medium, IR, Bluetooth, Internet, wireless network, radio, etc., or combinations thereof. The image acquirer can receive signals from the detector 240, can process the data included in the signals, and can construct an image from them. The image acquirer can thus acquire an image of sample 208. The image acquirer can also perform various post-processing functions, such as generating contours, overlaying indicators on the acquired image, etc. The image acquirer can be configured to perform adjustments such as brightness and contrast of the acquired image. The storage device can be a storage medium such as a hard disk, flash drive, cloud storage device, random access memory (RAM), or other types of computer-readable storage. The storage device can be coupled to the image acquisition device and can be used to store the original image data of the scan as the original image and the post-processed image.

[0039] Signal processing system 280 may include measurement circuitry (e.g., an analog-to-digital converter) to obtain the distribution of detected secondary electrons. Electron distribution data collected during the detection time window can be combined with corresponding scan path data of each of the primary sub-beams 211, 212, and 213 incident on the sample surface to reconstruct an image of the sample structure being evaluated. The reconstructed image can be used to reveal various features of the internal or external structure of sample 208. Therefore, the reconstructed image can be used to reveal any defects that may exist in the sample.

[0040] As mentioned, controller 50 can control stage 209 to move sample 208 during evaluation (e.g., inspection) of sample 208. Controller 50 can enable stage 209 to move sample 208 in one direction at least during sample evaluation, preferably continuously, for example, at a constant speed. Controller 50 can control the movement of stage 209 such that it varies the speed of movement of sample 208 according to various parameters. For example, controller 50 can control the speed (including its direction) based on the characteristics of the evaluation steps of the scanning process.

[0041] Known multi-beam systems (such as the charged particle system 40 and charged particle beam evaluation device 100 described above) are disclosed in US2020118784, US20200203116, US2019 / 0259570 and US2019 / 0259564, which are incorporated herein by reference.

[0042] like Figure 2 As shown, in one embodiment, the charged particle system 40 has a single charged particle device 41 and optionally includes a projection assembly 60. The projection assembly 60 may be a module and may be referred to as an ACC module. The projection assembly 60 is arranged to guide a beam 62 such that the beam 62 enters between the charged particle device 41 and the sample 208.

[0043] When the electron beam scans the sample 208, due to the large beam current, charge may accumulate on the sample 208, which may affect the image quality. In order to control the accumulated charge on the sample, a projection component 60 can be used to illuminate the sample 208 with a beam 62 to control the accumulated charge caused by effects such as photoconductivity, photoelectric or thermal effects.

[0044] The following is about Figures 3 to 9 Each and all of the accompanying drawings are used to describe the components that can be used in the charged particle system 40 of the present invention. Figures 3 to 9 These figures are schematic diagrams of charged particle system 40. The charged particle system 40 arranged as shown in these figures can correspond to the charged particle system mentioned above (which may also be referred to as a device or tool).

[0045] Considering Figure 7 In the arrangement shown, an electron source 201 directs electrons toward an array of condenser lenses 231 (also referred to as a condenser lens array). The electron source 201 is desiccated as a high-brightness emitter and is arranged to operate within an optimized range of electro-optical performance, which is a trade-off between brightness and total emission current (this trade-off can be considered a 'good' trade-off). The electron source emits a source beam. There may be tens, hundreds, thousands, or even tens of thousands of condenser lenses 231. The condenser lenses 231 may include multi-electrode lenses and have a construction based on EP1602121A1, which is incorporated herein by reference, particularly the disclosure of a lens array that splits the source beam into multiple sub-beams. A beam-most upbeam plate (which may be referred to as a beam-limiting aperture array and may be the beam-most upbeam plate of the condenser lens array) can generate multiple beams. An array of condenser lenses (which may include a beam-limiting aperture array) can provide lenses for each sub-beam. The focusing lens array 231 can take the form of at least two plates that act as electrodes, with the apertures in each plate aligned with each other and corresponding to the position of the sub-beam. The at least two plates are maintained at different potentials during operation to achieve the desired lensing effect.

[0046] In one arrangement, the condenser lens array 231 is formed by three plate arrays, where charged particles have the same energy when entering and leaving each lens; this arrangement can be referred to as a single lens. Therefore, dispersion occurs only within the single lens itself (between the entry and exit electrodes of the lens), thus limiting off-axis chromatic aberration. When the thickness of the condenser lens is low (e.g., a few millimeters), the effect of this aberration is small or negligible.

[0047] Each condenser lens 231 in the array directs electrons into a corresponding sub-beam 211, 212, 213, which is focused at a corresponding intermediate focal point downstream of the beam of the condenser lens array. The sub-beams diverge relative to each other. In an embodiment, a collimator, such as a deflector 235, is provided at the intermediate focal point. The collimator is positioned in the sub-beam path, at or at least around the corresponding intermediate focal point. The collimator is positioned in or near the sub-beam path, at the intermediate image plane of the associated sub-beam. The collimator is configured to operate on the corresponding sub-beam 211, 212, 213. The collimator is configured to bend the corresponding sub-beam 211, 212, 213 by an amount that effectively ensures that the principal ray (also referred to as the beam axis) is incident substantially normally onto the sample 208 (i.e., substantially at 90° to the nominal surface of the sample). A collimator (e.g., deflector 235) may also be referred to as a collimator deflector. Deflector 235 effectively collimates the paths of the sub-beams such that, prior to the deflector, the sub-beam paths diverge relative to each other. Downstream of the collimator's beam, the sub-beam paths are substantially parallel to each other, i.e., substantially collimated. A suitable collimator is the deflector disclosed in European Application 20156253.5, filed February 7, 2020, which is incorporated herein by reference with respect to applying the deflector to a multi-beam array. In embodiments of this arrangement, the collimator may include a macro-collimator, replacing or appending to deflector 235. The macro-collimator may be electrostatic, for example, as two or more planar plates having a single aperture.

[0048] A control lens array 250 is located below deflector 235 (i.e., downstream of the beam or further from source 201). Sub-beams 211, 212, and 213 passing through deflector 235 are substantially parallel as they enter the control lens array 250. The control lenses pre-focus the sub-beams (e.g., apply focusing to the sub-beams before they reach objective array 241). Pre-focusing can reduce divergence or increase convergence of the sub-beams. The control lens array 250 and objective array 241 operate together to provide a combined focal length. Combined operation without an intermediate focal point reduces the risk of aberrations. In embodiments, the control lenses in the control lens array can be considered as part of the objectives in the objective array. The electrode plates of the control lens array can be considered, in electro-optics terms, as additional electrode plates of the objective array.

[0049] It is desirable to use the control lens array 250 to determine the landing energy. However, the landing energy can also be controlled using the objective lens array 241. In this case, the potential difference on the objective lens changes when different landing energies are selected. However, considering the impact on the focal length, using the objective lens instead of the control lens to determine the landing energy may be less desirable, since the focal length of the objective lens is roughly proportional to the landing energy used.

[0050] The control lens array 250 includes a plurality of control lenses. Each control lens includes at least two electrodes (e.g., two or three electrodes) connected to a corresponding potential source. The control lens array 250 may include two or more (e.g., three) plate electrode arrays connected to the corresponding potential sources. The control lens array 250 is associated with the objective lens array 241 (e.g., the two arrays are positioned close to each other and / or mechanically connected to each other and / or controlled together as a unit). Each control lens may be associated with a corresponding objective lens. The control lens array 250 is positioned upstream of the beam of the objective lens array 241.

[0051] The control lens array 250 includes control lenses for each sub-bundle 211, 212, 213. The function of the control lens array 250 is to optimize the beam opening angle relative to the beam reduction rate and / or control the beam energy delivered to the objective array 241, which guides the sub-bundles 211, 212, 213 onto the sample 208. The objective array 241 may be positioned at or near the base of the charged particle device 41. The control lens array 250 is optional, but preferably used to optimize the sub-bundles upstream of the beam current of the objective array. In one arrangement, the control lens array 250 may be considered part of the objective array. A plate of the control lens array may be considered an additional plate of the objective array. Within an objective array satisfying this definition, the function of the control lens array may also be a function of the objective array in addition to the functions of the objective array described herein.

[0052] For ease of illustration, the lens array is schematically depicted in this paper using an elliptical array (e.g., Figure 7 As shown and Figure 8 and Figure 9 (In other words). Each ellipse represents one lens in a lens array. By convention, ellipses are used to represent lenses, similar to the biconvex form often used in optical lenses. However, in the context of charged particle arrangements such as those discussed herein, it should be understood that lens arrays will typically operate electrostatically, and therefore may not require any physical elements with a biconvex shape. Lens arrays can instead comprise multiple plates with apertures.

[0053] A scan deflector array 260 may be provided between the control lens array 250 and the objective lens array 234. The scan deflector array 260 includes a scan deflector for each sub-bundle 211, 212, 213. Each scan deflector is configured to deflect the corresponding sub-bundle 211, 212, 213 in one or both directions to scan the sub-bundle across sample 208 in one or both directions.

[0054] Due to the small size and special materials of the components, charged particle assessment systems (such as the charged particle system 40 described above) can be highly sensitive to contamination-induced malfunctions. One way to reduce contamination levels is to bake the degassing system by heating the components to high temperatures to increase the evaporation rate of the contaminants. This may result in significant downtime to allow sufficient time for baking the degassing system to clean the components.

[0055] There are several different ways to perform baking degassing. For example, individual components can be removed from the system and baked degassed in an oven. However, removing components for baking degassing in an oven is time-consuming, involving disassembly and reassembly. Furthermore, this method is limited to certain easily accessible and removable components. Moreover, the disassembly and reassembly process can become an additional source of contamination by introducing particles into the system. Opening the system for assembly and disassembly can also negatively impact aspects such as the alignment of components within the system (e.g., electro-optical components). Opening the system may allow unwanted contaminants from the ambient atmosphere to enter. The process of disassembling, removing components, baking degassing the removed components, and reassembling can take several months, during which time the charged particle system 40 cannot be used for evaluation.

[0056] Another method of performing baking degassing involves fitting a temperature-controlled heater for an external application, such as a depressurized vacuum chamber (i.e., a vacuum released toward ambient pressure), to the charged particle system 40 and covering the charged particle evaluation system with an insulating blanket. This allows the system to reach a partially elevated temperature. This method is effective in removing contaminants (i.e., cleaning), but during such cleaning, for example, the temperature of specific components and / or surfaces cannot be directly controlled. Therefore, it may be desirable to first remove heat-sensitive components that could be damaged by the high temperature. This baking degassing method may take one or two days (e.g., 24 to 48 hours) and requires additional time for removing heat-sensitive components, setting up and removing the temperature-controlled heater and insulating blanket, and reinstalling the heat-sensitive components. This can adversely affect the availability of the charged particle system 40.

[0057] Furthermore, the effectiveness of baking degassing is uncertain due to the lack of control over surface temperature within the system. Therefore, longer baking degassing cycles are typically applied to ensure adequate purification. However, the duration of baking degassing is too long, and frequent execution is not desirable. Consequently, longer intervals between baking degassing cycles may exist, potentially leading to the accumulation of higher levels of contamination and increasing the risk of malfunction.

[0058] Figure 3 A schematic diagram of a charged particle system 40 is shown, as referenced above. Figure 1 and Figure 2 The described charged particle system is used to fire a beam of charged particles toward a sample to examine the sample. Figure 3 The charged particle system 40 includes a source 201, a charged particle device 41, a support 210, a vacuum system, and a thermal control system. The source 201 is configured to emit a beam of charged particles, for example, as shown in the reference above. Figure 2 The source 201 is described in the manner described. The charged particle device 41 can be referenced above. Figure 1 and Figure 2 The described charged particle device 41 is configured to project a charged particle beam toward a sample. In an alternative configuration, source 201 can be considered a component of charged particle device 41. In other words, charged particle device 41 may optionally include source 201. Charged particle device 41 includes a plurality of charged particle optical elements 410 along the path of the charged particle beam. Support 210 is configured to support the sample. Support 210 may be disposed on stage 209, and for example, support 210 may include or be composed of sample holder 207, as described above. Figure 2 As described. Alternatively, support 210 may consist of platform 209, as described above. Figure 2 The described actuator stage 209.

[0059] Figure 3The charged particle system 40 includes a vacuum system. In other words, the charged particle system 40 is configured such that during use, at least some regions of the system are at pressures below atmospheric pressure. Specifically, the vacuum system includes a plurality of chambers 531, 532. One or more of the plurality of chambers may be those referenced above. Figure 1 The vacuum chamber 10 is described. The volume defined by the vacuum chamber 10 can be considered as one or more regions. Different chambers are configured to include at least one corresponding component, which includes at least one of a source 201 and one or more charged particle optical elements 410. In other words, the vacuum system includes at least two chambers. The different chambers include different components of the source and charged particle device, such that at least one chamber includes a source or charged particle optical element, and the other chamber includes a charged particle element different from that of the first chamber (if present). For example, in Figure 3 In this arrangement, the vacuum system includes a first chamber 531 and a second chamber 532. The first chamber 531 includes or contains a plurality of charged particle optical elements 410. The second chamber 532 includes or contains a source 201. In an alternative arrangement, one or more other chambers may be present, and one or more charged particle optical elements may be included in one or more other chambers. Additionally or alternatively, the source 201 may be included in the same chamber as one or more charged particle optical elements of the charged particle device 41. The vacuum system may include a vacuum chamber configured to include Figure 2 One or more portions of the projection system 60 shown. Alternatively or additionally, one or more portions of the projection system 60 may be included in the same cavity as one or more charged particle optical elements of the charged particle device 41.

[0060] The thermal control system of the charged particle system 40 is configured to independently and optionally simultaneously bake and degas different chambers. In other words, the thermal control system is configured to independently achieve baking and degassing in each chamber. Specifically, the temperature of one chamber can be increased to achieve localized baking and degassing within that chamber. In this way, it may be possible to perform localized baking and degassing on a single chamber, or even localized baking and degassing on specific components within a single chamber. The thermal control system can be configured such that baking and degassing in one chamber does not significantly affect the temperature of adjacent chambers. For example, in Figure 3In this arrangement, the thermal control system can be used to perform baking and degassing in the first chamber 531, without simultaneously performing baking and degassing in the second chamber 532. Using this arrangement, baking and degassing can be performed in a time- and energy-efficient manner. Energy may not be wasted on the heating chamber and associated components that do not require baking and degassing at that time or when at such high temperatures. Simultaneously, if these components are located in the unbaked chamber, more heat-sensitive components can be removed without wasting time. Therefore, when using references such as those described above… Figure 3 The described arrangement can significantly save time and reduce downtime of the baking and degassing system. Baking and degassing can be selectively applied to components. Some parts of the charged particle system 40 can be baked and degassed more frequently or more often than others, for example, to maintain the operating conditions of the corresponding parts of the charged particle system. By placing different parts in different vacuum chambers, the components and parts of the charged particle system can undergo baking and degassing individually or even independently of each other. This may allow baking and degassing (especially for the most critical or most frequently contaminated components) to be performed more frequently, thereby reducing the risk of failure that could otherwise lead to further increases in downtime. Note that even though baking and degassing can be performed independently in different areas, it is sometimes possible to bake and degas multiple chambers or even all chambers of the charged particle system 40 simultaneously.

[0061] Furthermore, performing baking degassing in a targeted local area of ​​the system, rather than over a larger area (such as the charged particle system 40 or the charged particle device 41 as a whole), allows for more targeted use of temperature. For example, global baking degassing of a vacuum system at approximately 100°C could take several days. In such global baking degassing, the temperature may not be significantly increased because some components within the vacuum system may be too heat-sensitive to withstand higher temperatures. Providing multiple chambers and a temperature control system capable of independently controlling the temperature and baking degassing in different chambers could allow some chambers to be baked degassed at higher temperatures (such as 250 to 300°C) without risking damage to more heat-sensitive components in other chambers. Targeted baking degassing using higher temperatures in certain chambers containing certain components allows those chambers / components to undergo baking degassing more quickly than baking degassing at lower temperatures. For example, the same purification effect could be achieved by baking degassing at 250°C for several hours, rather than baking degassing at 100°C for several days. Therefore, the baking and degassing of some critical components or chambers can be performed significantly faster, thereby reducing downtime. This means that, if necessary, the baking and degassing of these components can be performed more frequently, thus reducing the risk of failure and the need for component replacement.

[0062] like Figure 3As shown, the thermal control system includes a thermal regulator associated with a corresponding chamber of the vacuum system, in this case, a heater 511, 512. The thermal regulator is configured to change the temperature of the corresponding chamber. The thermal regulator may include a heater and / or a cooling element. Such a heater can apply heat to components of the charged particle system in vacuum chambers 531, 532. Such a cooling element can be used to regulate or harmonize the heat load applied to different components or different parts of components, the heat load of which is applied to the different components or different parts of components. Such a cooling element can be used to shield or protect sensitive parts or components of components or different components within the chamber from excessively high temperatures. Such excessively high temperatures above a temperature threshold may cause degradation of the integrity and / or function of sensitive parts or components. It is desirable that at least one thermal regulator be associated with each chamber that may require baking for degassing. For example, each chamber may be associated with at least one corresponding element, such as a heater and / or a cooling element, possibly multiple corresponding heaters configured to heat the chamber.

[0063] The heater is desiccated to heat at least a portion of at least one corresponding component within a corresponding chamber. At least a portion of the corresponding component is desiccated to be heat-resistant. In other words, the heater may be disposed on, near, or within at least a portion of the at least one corresponding component. The heat-resistant portion of the at least one component is desiccated to withstand temperatures, for example, 100°C, desiccated to 200°C, more desiccated to 250°C, or even more desiccated to 300°C. For example, the heat-resistant portion of the at least one component may comprise, or be composed of, ceramic, silicon, or quartz.

[0064] A thermal control system can be used to control heaters to locally bake and degas at least a portion of at least one corresponding component. This can provide even more localized baking and degassing within the corresponding chamber. For example, multiple heaters can be optionally provided to correspond to different corresponding components within the same corresponding chamber. In this way, high-temperature baking and degassing can be performed on a specific component while maintaining a slightly lower temperature in the rest of the chamber, without the need to simultaneously bake and degas any adjacent chambers. At least one corresponding component may include at least one of the following: a source 210, a support 210, and at least one charged particle optical element 410. Thus, two or more components of the vacuum chamber can be locally heated. For example, in Figure 3 In the charged particle system, at least one corresponding component of the first chamber 531 is at least one charged particle optical element in the charged particle optical element 410, and at least one corresponding component of the second chamber 532 is the source 201. For example, as Figure 3 As shown, source 201 is intended to be located in a different chamber from one or more charged particle optical elements 410.

[0065] exist Figure 3 In this arrangement, a first heater 511 is associated with a first chamber 511, and a second heater 512 is associated with a second chamber 532. The first heater 511 is configured to increase the temperature of the first chamber 531 when the thermal control system initiates baking and degassing of the first chamber 511. The second heater 512 is configured to increase the temperature of the second chamber 531 when the thermal control system initiates baking and degassing of the second chamber 532. A thermal regulator can be directly connected to the corresponding chamber to adjust the temperature of the corresponding chamber. For example, as... Figure 3 As shown, heaters 511 and 512 can be disposed within the internal spaces of corresponding chambers 531 and 532 of the vacuum system. The internal space of the corresponding chamber can be defined by the inner surface of the wall 550 defining the corresponding chamber.

[0066] In an alternative arrangement, a thermal regulator (e.g., a heater) may be at least partially embedded within the wall of the corresponding chamber defining the vacuum system. For example, the thermal regulator may be flush with the inner surface of the wall defining the corresponding chamber. In other words, the innermost surface of the thermal regulator facing the internal space of the corresponding chamber may form a flat plane with the inner surface of the wall 511 defining the corresponding chamber. /

[0067] Figure 4 Depicting the opposite of the above Figure 3 A similar charged particle system 40 is described. Figure 4 All features with the same reference numerals are intended to be consistent with those in the above reference. Figure 3 The descriptions are the same. Figure 4 The layout and Figure 3 The only difference in their arrangement is the placement of heaters 511 and 512. Figure 3 In the arrangement, as described above, heaters 511 and 512 are disposed in corresponding chambers 531 and 532. Figure 4 The arrangement similarly includes a first heater 511 associated with the first chamber 531 and a second heater 512 associated with the second chamber 532. However, Figure 4 The heaters 511 and 512 are fully embedded in the walls 550 of the corresponding chambers 531 and 532 of the defined vacuum system.

[0068] In an alternative arrangement, the thermal control system may include multiple heaters. One or more heaters may be located within a corresponding chamber. One or more heaters may be located within a wall defining the corresponding chamber. One or more chambers may be associated with multiple corresponding heaters. In other words, multiple heaters may be associated with the same corresponding chamber. Each of the multiple heaters may be provided within the same corresponding chamber. Alternatively, one or more of the multiple heaters may be embedded in a wall (such as an inner or outer wall) defining the corresponding chamber.

[0069] In some arrangements, a thermal regulator (such as a heater) may be disposed on, near, or within at least a portion of a corresponding component within a corresponding chamber. For example, a local thermal regulator, such as a resistance trace or fluid conduit, may be provided within a component (such as an electro-optical component) of the charged particle device 41. A component may serve multiple purposes and may also act as a local thermal regulator (and vice versa) in addition to serving another purpose. For example, portions of such a component may include connectors, feedthroughs, flex elements, and potting. Flex elements or printed circuit boards (PCBs) are typically used to provide electrical connections between different portions of a component. Such PCBs are also examples of bases for electronic devices or other electrical components in a charged particle system. Resistance traces, such as flex elements and / or PCBs, may be provided within such connectors or bases to perform heating functions as needed. Such traces may be existing electrical connections or wires or additional connectors or wires. A portion of a component (and therefore the component) may include plastics and metals, such as copper, such as copper wire. Some of these materials are larger sources of contamination, sometimes referred to as degassing. Such sources of contamination are, for example, plastics and ceramics. During baking and degassing, the plastic is heated to remove contaminants. This contamination may be referred to as degassing. Degassing materials include water and hydrocarbons, for example, in gaseous form. Resistive traces may generate heat when conducting current. Alternatively or additionally, a separate resistor (or other resistive element) may be used to provide heat. Heat can be generated by passing current through such a resistor or resistive element. Such resistors and resistive elements heat up and, when they are close to or even integrated into parts such as connectors, cause at least a localized area of ​​the part to heat up. Such resistive elements can be applied to and / or integrated into bases such as PCBs, cables and connectors such as flexible cables, and potting compounds used to suppress electric fields. Such separate wires or traces provided within, in, or on such a part will heat up that part and even the components that include it. Resistors or resistive elements may be located within the area of ​​the part, and thus within the area of ​​the component, to achieve the desired heating. Using this heating element allows for localized heating, enabling the localized baking and degassing of a portion, without heating the entire portion, let alone the entire component or even the chamber it resides in.

[0070] like Figure 4 As shown, the wall 550 defining the corresponding chamber may include the outer wall 551 of the vacuum system. In particular, the wall 550 where the heaters 511 and 512 are embedded is the outer wall 551 of the corresponding chambers 531 and 532. The outer wall 551 is the wall 550 between the external environment and the vacuum environment, which is the environment within the corresponding chamber including at least one corresponding component.

[0071] In the alternative arrangement, the wall 550 defining the corresponding chamber can be the inner wall 552 of the vacuum system. In other words, in the alternative arrangement ( Figure 4 (Not shown in the diagram), one or more heaters may be embedded in the inner wall 552 of the vacuum system, wherein the inner wall 552 is the wall between the vacuum environments of different chambers. Figure 3 and Figure 4 In the arrangement shown, the inner wall 552 separates two different chambers of the vacuum system, specifically separating the first chamber 531 and the second chamber 532.

[0072] The vacuum system desiccates to include a thermal shield between different chambers, for example, between a first chamber 531 and a second chamber 532. The inner walls of the vacuum system are configured to separate and thermally shield the different chambers. For example, the inner wall 552 separating the first chamber 531 and the second chamber 532 can be thermally insulated. In this way, heat transfer between the different chambers can be reduced, and temperature changes (such as during baking and degassing) can be applied independently to the different chambers. Therefore, baking and degassing of one chamber can be performed at different temperatures and / or at different times relative to baking and degassing of another chamber within the vacuum system.

[0073] For example, such as Figure 3 and Figure 4 As shown, the thermal control system optionally includes thermal sensors 521 and 522, which are configured to thermally sense the temperature in corresponding chambers 531 and 532. Figure 3 and Figure 4 In the arrangement, the thermal control system includes multiple thermal sensors 521, 522. Each thermal sensor is associated with a corresponding chamber 531, 532. The thermal control system may include at least one thermal sensor 521, which is configured to detect the temperature at or near at least a portion of a corresponding component. For example, in Figure 3 and Figure 4 In this arrangement, a second thermal sensor 522 is configured to detect the temperature of the source 201, such as a degassing portion of the chamber wall or a source mounting portion. In this way, during baking and degassing, the thermal control system can monitor the temperature detected by the second thermal sensor 522, determine whether the maximum permissible temperature of the source 201 has been reached or exceeded, and if so, control the second heater 512 to reduce the temperature of the second chamber 532. In this way, the temperature of each heater can be controlled to maintain the desired temperature of at least one corresponding component during baking and degassing.

[0074] Optionally, more than one thermal sensor may be associated with the same corresponding chamber. For example, in a chamber housing multiple corresponding components, multiple thermal sensors may be provided, each associated with at least one corresponding component. Alternatively or additionally, the thermal sensor may be configured to thermally sense the temperature of the corresponding thermal regulator. For example, one or more heaters of the thermal control system may be associated with a corresponding thermal sensor configured to detect the temperature at or near the heater. In this way, it may be possible to monitor the temperature of the heater and the temperature of at least one corresponding component in the corresponding chamber undergoing baking and degassing.

[0075] The thermal sensor can be disposed on the inner surface of the wall defining the corresponding chamber. Alternatively, the thermal sensor can be partially or completely embedded in the wall, such as the outer or inner wall of the chamber, or in a base for a component to be attached to or integrated into the chamber wall.

[0076] exist Figure 3 and Figure 4 In the charged particle system 40, the thermal control system includes a thermal controller 500 configured to control one or more thermal regulators. Specifically, the controller 500 is desiccated to apply thermal control to independently achieve baking degassing of respective chambers. Thermal control may include controlling the thermal regulators (or, if more than one thermal regulator exists, controlling different thermal regulators). Such thermal control (or regulation) may include setting a target temperature for the corresponding heater associated with the respective chamber undergoing baking degassing. If more than one heater exists, different heaters are associated with the chamber undergoing baking degassing (note that multiple heaters may operate on the same chamber). A controlled thermal regulator (or a thermal regulator when there is more than one thermal regulator) may be associated with one or more adjacent chambers without undergoing baking degassing. Thermal regulators associated with chambers not undergoing baking degassing may operate at different times to bake degas the chambers. Thermal control may be provided based on predetermined, predefined target parameters associated with a particular chamber, thermal regulator, and / or corresponding component. This parameter can be at least one of the following: target temperature, component sensitivity, and component operating requirements, such as cleanliness requirements for maintaining the contamination level of the chamber and / or components. This parameter can at least partially determine the operating frequency, such as for ensuring adequate cleanliness of the components. This contamination may include a degree of degassing. For example, thermal control can be based on one or more pre-programmed sequences.

[0077] The thermal control system preferably includes multiple corresponding independently controllable thermal regulators. These multiple independently controllable thermal regulators preferably include multiple corresponding independently controllable heaters 511, 512.

[0078] exist Figure 3 and Figure 4In this arrangement, multiple chambers include a first chamber 531 and a second chamber 532. Multiple corresponding independently controllable heaters 511, 512 include a first corresponding independently controllable heater 511 associated with the first chamber 531 and a second corresponding independently controllable heater 512 associated with the second chamber 532. A thermal controller 500 is configured to independently control the first corresponding independently controllable heater 511 to achieve baking degassing within the first chamber 531. During baking degassing, a vacuum is desired to be maintained within the first chamber 531. Similarly, the thermal controller 500 is configured to independently control the second corresponding independently controllable heater 512 to achieve baking degassing within the second chamber 532. During baking degassing, a vacuum is desired to be maintained within the second chamber 532.

[0079] The thermal control system is desirably configured such that baking degassing occurs locally within a chamber associated with a corresponding independently controllable heater controlled to achieve baking degassing. In other words, the thermal control system is desirably configured such that the first chamber 531 can undergo baking degassing without simultaneously baking degassing the second chamber 532, and vice versa. In one arrangement, baking degassing can be locally performed within the chamber on the component undergoing baking degassing (which may be a specific component or a target component). This baking degassing can be limited to the target component.

[0080] Thermal control can be based on thermal signals from one or more thermal sensors. For example, if the second thermal sensor 522 detects a temperature exceeding the desired baking and degassing temperature of the second chamber 532, the target temperature of the second heater 512 can be reduced. Additionally or alternatively, if the second thermal sensor 522 detects a temperature exceeding a predetermined threshold temperature based on the maximum temperature that the source 201, as at least one corresponding component, can safely withstand, the target temperature of the second heater 512 can be reduced.

[0081] The heater can be any type of heater suitable for a vacuum environment. For example, the heater can include resistive elements, such as resistive traces. In other words, a length of resistive material, such as in a ring, spiral, coil, or meandering shape, can be provided in a dense arrangement. Using a heating element of this form can help ensure that a portion (or even a component) of a part is heated to optimally bake and degas the desired area of ​​the portion (and, for example, the component). The form of a trace allows heating to be applied to that portion while avoiding sensitive areas of the portion and component. Similarly, the cooling element can be any type of cooling element suitable for a vacuum environment. For example, the cooling element can be a fluid conduit. The length of the cooling element (such as a fluid conduit) can be arranged in a ring, spiral, coil, or meandering shape or any other meandering form. The path of the cooling element or heater can be designed to apply the heat load in a distributed manner, intended to apply the heat load to the intended target part or portion of the charged particle device.

[0082] Multiple corresponding independently controllable thermal regulators may optionally include multiple corresponding independently controllable cooling elements. Cooling elements may be provided near more heat-sensitive components and / or portions of the chamber. Cooling elements may be used to maintain or even reduce the temperature in chambers adjacent to the chamber undergoing bake-degassing. Alternatively or additionally, cooling elements may be used to locally reduce the temperature of areas (e.g., localized areas) within the chamber undergoing bake-degassing. In this way, certain components and / or portions can undergo relatively rapid bake-degassing at high temperatures, while all components in the same chamber do not need to be subjected to the same high temperatures. Sensitive components in the same or different chambers can be thermally shielded by the operation of the cooling elements.

[0083] The vacuum system may optionally include valves located between different adjoining chambers. For example, in Figure 3 and Figure 4 In this arrangement, a valve may be provided between the first chamber 531 and the second chamber 532. The valve is desiccated when the thermal regulator is operated in at least one adjacent chamber. For example, the valve may be closed during bake-degassing of one of the chambers. The valve may be opened during system evacuation. Closing the valve may help ensure that any pressure changes within the vacuum chamber are only localized to the chamber undergoing bake-degassing. One purpose of bake-degassing is to remove contaminants, such as degassed material, from components of the charged particle system 40. Degassed material is typically gaseous and may consist of water and / or hydrocarbons. During degassing, the pressure within the baked-degassed chamber may increase. Closing the valve connecting the vacuum chamber to an adjacent chamber limits the pressure increase to the chamber undergoing degassing. Between adjacent chambers undergoing degassing, valves may be closed. This ensures that degassing in one chamber does not unduly affect the pressure in another chamber. Limiting pressure changes can restrict or even prevent contaminating fluids (e.g., degassing) from entering (e.g., migrating) into different chambers. Unless contamination is removed while maintaining a vacuum, the contamination (and pressure increase) is confined to the chamber in which it resides. Such valves can be found between adjacent chambers in charged particle systems with multiple chambers, such as reference... Figures 6 to 10 As shown and described.

[0084] The vacuum system can optionally be configured to bake degassing during evacuation. During evacuation, this baking degassing can be applied to selected chambers (which may be one, some, or all chambers) or to specific components or selected components within specific selected chambers. This can reduce the time required for a charged particle system to return to operation after maintenance performed at atmospheric pressure. This baking degassing may have occurred prior to initiating evacuation, such as when removing components intended for baking degassing, for example, in a baking degassing furnace, and / or during evacuation of a full vacuum system, where all chambers (e.g., the full vacuum system) have previously undergone this baking degassing.

[0085] exist Figure 5 In this embodiment, the charged particle system 40 includes a source 201. Unless stated otherwise, the features, functions, benefits, and advantages of the invention described with reference to earlier embodiments apply to this embodiment. Source 201 provides a beam of charged particles (e.g., electrons). Multiple beams focused on sample 208 are derived from the beam provided by source 201. For example, a beam limiter defining a beam-limiting aperture array can be used to derive sub-beams from the beam. For example, as... Figure 5 As shown, in one embodiment, the charged particle device 41 includes an upper beam limiter 252 that defines a beam-limiting aperture array. The upper beam limiter 252 may include a plate (which may be plate-shaped) having multiple apertures.

[0086] Source 201 is intended to be a high-brightness thermal field emitter with a good trade-off between luminance and total emission current. In the illustrated example, a collimator is provided upstream of the beam current of the objective array assembly. The collimator may include a macro-collimator 270. The macro-collimator 270 acts on the beam from source 201 before the beam is split into multiple beams. The macro-collimator 270 bends the corresponding portions of the beam by an amount that effectively ensures that the beam axis of each sub-beam derived from the beam is incident substantially normally onto sample 208 (i.e., substantially at 90° to the nominal surface of sample 208). The macro-collimator 270 applies macro-collimation to the beam. Therefore, the macro-collimator 270 can act on all beams, rather than including an array of collimator elements, each collimator element being configured to act on a different individual portion of the beam. The macro-collimator 270 may include magnetic lenses or magnetic lens arrangements comprising multiple magnetic lens subunits (e.g., multiple electromagnets forming a multipole arrangement). Alternatively or additionally, the macrocollimator can be at least partially electrostatic, for example, fully electrostatic. The macrocollimator may include electrostatic lenses or an arrangement of electrostatic lenses comprising multiple electrostatic lens subunits. Macrocollimator 270 may use a combination of magnetic lenses and electrostatic lenses. Desiredly, macrocollimator 270 uses only electrostatic lenses.

[0087] exist Figure 5In one embodiment, a macro-scan deflector 265 is provided to scan a sub-beam over sample 208. The macro-scan deflector 265 deflects corresponding portions of the beam to scan the sub-beam over sample 208. In another embodiment, the macro-scan deflector 256 includes a macro multipole deflector, for example, having eight or more poles. The macro-scan deflector can be electrostatic or magnetic. Deflection, for example, causes sub-beams derived from the beam to be scanned across sample 208 in one direction (e.g., parallel to a single axis, such as the X-axis) or in two directions (e.g., relative to two non-parallel axes, such as the X-axis and Y-axis). The macro-scan deflector 265 acts macroscopically on all beams, rather than comprising an array of deflector elements, each deflector element being configured to act on a different, separate portion of the beam. In the illustrated embodiment, the macro-scan deflector 265 is provided between the macro-collimator 270 and the control lens array 250.

[0088] In other embodiments, such as reference Figure 5 A variation of the arrangement shown and described provides a macro-scan deflector 265 and a scan deflector array 260. In this arrangement, scanning of the sub-beams on the sample surface can be achieved by controlling the macro-scan deflector and the scan deflector array 260 together (preferably synchronously). The variation may include a macro-collimator 270 and a collimator array, thereby distributing the collimation effect throughout the entire column. In the variation, the scan deflector function can be implemented using a scan deflector array having deflectors for one or more of the multiple sub-beams. This scan deflector array may be located between the control lens array 250 and the objective lens array 241. In the variation, the collimator function can be implemented using a collimator array comprising collimating elements for operating on different sub-beams of the multiple beams. These collimating elements may be deflectors. The collimator array may be associated with the control lens array, for example, upstream of the beam of the control lens array. The arrangement of the charged particle device having such a collimator array and scan deflector array is... Figure 9 The apparatus among the multiple devices shown. That is, although the macro-elements of the collimator and the scan deflector exist as collimator arrays and scan deflector arrays rather than macro-components, reference is made to... Figure 9 The functionality of each device in the charged particle apparatus shown and described can correspond to the reference. Figure 5 The functionality of the charged particle device shown and described.

[0089] In other embodiments, a macro-scan deflector and a scan deflector array are provided. In this arrangement, scanning of the sub-beams on the sample surface can be achieved by controlling the macro-scan deflector and the scan deflector array together (preferably synchronously).

[0090] The objective array assembly may also include a beam-shaping limiter 242. The beam-shaping limiter 242 defines a beam-limiting aperture array. In one arrangement, the beam-shaping limiter 242 is structurally integrated with the electrodes of the objective array 241. Desiredly, the beam-shaping limiter 242 is positioned in a region of low electrostatic field strength. Each beam-limiting aperture is aligned with a corresponding objective in the objective array 241.

[0091] Figure 5 and Figure 9 Electro-optical systems also include detectors (not shown), such as those described below. Figure 7 The detector 240 described below (as further described below) is, ideally, an array of detectors.

[0092] like Figure 5 As shown, the charged particle system 40 includes a vacuum system comprising multiple chambers. The chambers are defined by the inner surfaces of an outer wall 551 and an inner wall 552 of the vacuum system. Figure 5 The charged particle system 40 also includes a thermal control system, such as the one mentioned above. Figure 3 and Figure 4 A thermal control system as described. For example, Figure 5 The arrangement includes multiple heaters 510 associated with corresponding chambers of the vacuum system. For example... Figure 5 As shown, source 201 can be provided in a separate chamber of the charged particle optical element of charged particle device 41. The chamber housing source 201 includes heater 510. Other chambers may optionally include one or more heaters 510, such as... Figure 5 As shown. In Figure 5 In the example arrangement shown, the macro-scan deflector 265 and the macro-collimator 270 are provided in the same chamber. Another chamber includes the control lens array 250 and the objective lens array 241. However, in alternative arrangements, there may be different numbers of inner walls 552 and / or the inner walls may be positioned differently, such that the components of the charged particle device 41 are distributed differently within the chambers. The sample 208 may be provided on a sample holder or support, which may be included in another chamber. Different chamber arrangements are selected to demonstrate a suitable arrangement. As needed, there may be as many or as few walls as possible, for example, located between different components along the charged particle beam path and / or between the source 201 and the sample location.

[0093] Now for reference Figure 6 It is an evaluation device (e.g.) Figure 1A schematic diagram of an exemplary multi-beam charged particle device 41 (evaluation device 100). Unless otherwise stated, the features of the previously described embodiments are the same. Unless otherwise stated, the features, functions, benefits, and advantages of the invention described with reference to the earlier embodiments apply to this embodiment. Similarly, unless otherwise stated, reference is made to the embodiments (see reference...). Figure 6 The features, benefits, functions, and advantages described herein apply to the previously mentioned embodiments.

[0094] As depicted, the charged particle device 41 may include an electron source 201, a beamformer array 372 (also referred to as a perforated plate, coulomb aperture array, or pre-beamforming aperture array), a condenser lens 310, a source converter (or micro-optical array) 320, an objective lens 331, and a target 308. In an embodiment, the condenser lens 310 is magnetic. The target 308 may be supported by a support on a stage. The stage may be motorized. The stage moves such that the target 308 is scanned by incident electrons. The electron source 201, beamformer array 372, and condenser lens 310 may be components of the irradiation equipment included in the charged particle optical device 41. The source converter 320 (also referred to as a source conversion unit) and objective lens 331, described in more detail below, may be components of the projection equipment included in the charged particle optical device 41.

[0095] An electron source 201, a beamformer array 372, a condenser lens 310, a source converter 320, and an objective lens 331 are aligned with the primary electron optical axis 304 of the charged particle optical device 41. The electron source 201 can generate a primary beam 302 that is generally along the electron optical axis 304 and has source crossovers (virtual or real) 301S. During operation, the electron source 201 is configured to emit electrons. The electrons are extracted or accelerated by an extractor and / or an anode to form the primary beam 302.

[0096] The beamformer array 372 cuts the peripheral electrons of the primary electron beam 302 to reduce the resulting Coulomb effect. The primary electron beam 302 can be trimmed by the beamformer array 372 into a specified number of sub-beams, such as three sub-beams 311, 312, and 313. It should be understood that this description is intended to apply to charged particle devices 41 having any number of sub-beams, such as one, two, or more than three. In operation, the beamformer array 372 is configured to block peripheral electrons to reduce the Coulomb effect.

[0097] Source converter 320 is configured to convert the beam (including sub-beams, if present) transmitted by beamformer array 372 into sub-beams projected toward target 308. In embodiments, the source converter is a unit. Alternatively, the term source converter can be simply used as a collective term for a group of components that form beam waves from sub-beams.

[0098] like Figure 6As shown, in one embodiment, the charged particle device 41 includes a beam-limiting aperture array 321 having an aperture pattern (i.e., apertures arranged in formation) configured to define the outer dimensions of a beam (or sub-beam) projected toward the target 308. In one embodiment, the beam-limiting aperture array 321 is part of a source converter 320. In an alternative embodiment, the beam-limiting aperture array 321 is part of the system upstream of the beam current of the main device. In one embodiment, the beam-limiting aperture array 321 divides one or more sub-beams 311, 312, 313 into beams such that the number of beams projected toward the target 308 is greater than the number of sub-beams transmitted through the beamformer array 372. In an alternative embodiment, the beam-limiting aperture array 321 maintains a number of sub-beams incident on the beam-limiting aperture array 321, in which case the number of sub-beams may be equal to the number of beams projected toward the target 308.

[0099] like Figure 6 As shown, in one embodiment, the charged particle device 41 includes a pre-bending deflector array 323 having pre-bending deflectors 323_1, 323_2, and 323_3 to bend sub-bundles 311, 312, and 313, respectively. The pre-bending deflectors 323_1, 323_2, and 323_3 can bend the paths of sub-bundles 311, 312, and 313 onto the beam-limiting aperture array 321.

[0100] The charged particle device 41 may also include an image forming element array 322 having image forming deflectors 322_1, 322_2, and 322_3. A corresponding deflector 322_1, 322_2, and 322_3 is associated with the path of each beam. The deflectors 322_1, 322_2, and 322_3 are configured to deflect the path of the beam toward the electron optical axis 304. The deflected beam forms a virtual image (not shown) of the source crossing 301. In the current embodiment, these virtual images are projected onto the target 308 via an objective lens 331, and probe spots 391, 392, and 393 are formed thereon. The charged particle device 41 may also include an aberration compensator array 324 configured to compensate for aberrations that may exist in each sub-beam. In an embodiment, the aberration compensator array 324 includes lenses configured to operate on the corresponding beams. The lenses may take the form of a lens array. The lenses in the array can operate on different beams of multiple beams. The aberration compensator array 324 may, for example, include an array of field curvature compensators (not shown) with microlenses. For example, the field curvature compensators and microlenses can be configured to compensate for individual sub-beams for field curvature aberrations present in probe spots 391, 392, and 393. The aberration compensator array 324 may include an array of astigmatism compensators (not shown) with micro-astigmatism ablation devices. For example, the micro-astigmatism ablation devices can be controlled to operate on the sub-beams to compensate for astigmatic aberrations present in probe spots 391, 392, and 393.

[0101] The image forming element array 322, aberration compensator array 324, and pre-bending deflector array 323 may include multi-layer sub-beam manipulation devices, some of which may be in array form, such as micro-deflectors, microlenses, or micro-astigmatism reducers. The beam path can be rotated. Rotation correction can be applied via magnetic lenses. Rotation correction can be additionally or alternatively achieved using existing magnetic lenses, such as condenser lens arrangements.

[0102] Objective lens 331 focuses the beam onto the surface of target 308; that is, it projects three virtual images onto the target surface. The three images formed on the target surface by the three sub-beams 311 to 313 form three probe spots 391, 392, and 393 thereon. In an embodiment, the deflection angles of the sub-beams 311 to 313 are adjusted to pass through or approach the front focal point of objective lens 331 to reduce or limit off-axis aberrations of the three probe spots 391 to 393. In one arrangement, objective lens 331 is magnetic. Although three beams are mentioned, this is only by way of example. Any number of beams may be used.

[0103] In this embodiment, a beam splitter (not shown) is provided. The beam splitter may be downstream of the beam of source converter 320. The beam splitter may be, for example, a Wien filter comprising an electrostatic dipole field and a magnetic dipole field. The beam splitter may be upstream of the beam of objective lens 331. In operation, the beam splitter may be configured to apply an electrostatic force to the individual electrons of the sub-beam via the electrostatic dipole field. In this embodiment, the magnitude of the electrostatic force is equal to, but opposite in direction to, the magnetic force applied by the magnetic dipole field of the beam splitter to the individual primary electrons of the sub-beam. Therefore, the sub-beam can pass through the beam splitter at least substantially straight with a deflection angle of at least substantially zero. The direction of the magnetic force depends on the direction of electron motion, while the direction of the electrostatic force does not depend on the direction of electron motion. Therefore, since secondary electrons and backscattered electrons (or signal electrons) generally move in the opposite direction to the primary electrons, the magnetic force applied to the secondary electrons and backscattered electrons (or signal electrons) will no longer cancel out the electrostatic force, and thus the secondary electrons and backscattered electrons moving through the beam splitter will be deflected away from the electron optical axis 304.

[0104] In one embodiment, a secondary device (not shown) is provided, comprising detection elements for detecting a corresponding secondary charged particle beam. When the secondary beam is incident using the detection elements, these elements can generate a corresponding intensity signal output. The output can be directed to an image processing system (e.g., controller 50). Each detection element can include an array, which can be in the form of a grid. The array can have one or more pixels; each pixel can correspond to an element in the array. The intensity signal output of the detection element can be the sum of signals generated by all pixels within the detection element.

[0105] In one embodiment, a secondary projection device and its associated electronic detection device (not shown) are provided. The secondary projection device and its associated electronic detection device can be aligned with the secondary electron optical axis of the secondary device. In one embodiment, a beam splitter is arranged to deflect the path of the secondary electron beam toward the secondary projection device. The secondary projection device then focuses the path of the secondary electron beam onto multiple detection areas of the electronic detection device. The secondary projection device and its associated electronic detection device can use secondary electrons or backscattered electrons (or signal electrons) to register and generate an image of target 308.

[0106] Such Wien filters, secondary devices, and / or secondary projection devices can be provided in a single-beam evaluation device. Additionally and / or alternatively, the detection device can be located downstream of the beam of the objective lens, for example, facing the sample during operation. In an alternative arrangement, the detector device is positioned along the path of the charged particle beam toward the sample. This arrangement does not have Wien filters, secondary devices, and secondary projection devices. The detection device can be positioned at one or more locations along the path of the charged particle beam toward the sample, such as facing the sample during operation, for example, around the path of the charged particle beam. Such detector devices can have an aperture and can be annular. Different detector devices can be positioned along the path of the charged particles to detect signal particles with different characteristics. Electro-optical elements along the path of the charged particle beam, which may include one or more electrostatic plates (with apertures for the charged particle beam path), can be arranged and controlled to focus signal particles with different corresponding characteristics onto corresponding detector devices at different locations along the path of the charged particle beam. Such electrostatic plates can be arranged in series of two or more adjacent plates along the path of the charged particle beam.

[0107] Any component or assembly of components within the charged particle optics device is replaceable or field-replaceable. Such components or assemblies can be included in modules of the charged particle system 40. This replaceability means, for example, that such modules can be removed and replaced with replaceable modules, even in the field, without substantially disassembling the rest of the charged particle system 40. One or more electro-optical components in the charged particle optics device, particularly those that operate on or generate sub-beams (such as aperture arrays and manipulator arrays), may include one or more plates, each plate being an electrode, or may include one or more electrodes for each aperture of the array. In embodiments, manipulators such as lenses and deflectors 322_1, 322_2, and 322_3 are passively controllable, actively controllable, controllable as a whole array, and controllable individually or in groups within the array to control the beam of charged particles projected toward target 308.

[0108] like Figure 6As shown, the charged particle system 40 includes a vacuum system comprising multiple chambers. The chambers are defined by the inner surfaces of an outer wall 551 and an inner wall 552 of the vacuum system. Figure 6 The charged particle system 40 also includes a thermal control system, such as the one mentioned above. Figure 3 and Figure 4 A thermal control system as described. For example, Figure 6 The arrangement includes multiple heaters 510 associated with corresponding chambers of the vacuum system. For example... Figure 6 As shown, source 201 is provided in a separate chamber of the charged particle optical element of charged particle device 41. Heater 510 is provided to heat source 201, thereby baking and degassing source 201. Figure 6 In the example arrangement shown, a condenser lens 310 is provided in a dedicated chamber, a source converter 320 is provided in an adjacent chamber, and an objective lens 331 is provided in another chamber. A sample 208 may be provided on a sample holder or support, which may be included in the other chamber.

[0109] Certain components may be included in separable or removable modules, such as the different features of source module 320. Electro-optical components may be an array of components with electrically isolated supports, comprising materials susceptible to contamination (e.g., degassing). Such materials may be hygroscopic, such as plastics and / or ceramics. Associated with the electro-optical components of the source module may be electronics, which may be mounted on supports such as PCBs or potting compounds to confine the electric field. Communication and power may be provided, for example, through feedthroughs in the chamber walls, to electrically connect the electronics, electro-optical components, and an external controller. Cables such as flexible cables may provide this electrical connection. The module may have actuators to position the electro-optical components relative to source 201 (or at least the path of the charged particle beam).

[0110] Different components can include materials that can be sources of contamination, such as cables with plastic exteriors, and electronic bases such as PCBs with plastic substrates. This contamination may be due to degassing. Baking degassing can be used to remove and thus suppress degassing during operation. Degassing can be suppressed by carefully selecting materials, and even if it cannot be avoided, the use of easily degassing materials should be limited. However, some degassing from most surfaces in the vacuum chamber will be expected.

[0111] Thermal regulators can be used to apply baking degassing heating. This part (or component or element) can be an additional component of the module and / or an existing part of the module, such as an electronic base (such as a PCB) and electrical connections (such as flexible cables). The PCB may include additional resistive traces, such as meandering traces as part of the PCB surface, which will heat up when current is conducted. Similar electric heat tracing arrangements can be incorporated into the potting compound. Operation of actuators may cause the electrical connections of the motor and / or actuator to generate heat. Cables can be designed to carry higher currents to generate heat during baking degassing. This heater can be located where heat is most needed during baking degassing, such as away from thermistor electronics. Additionally or alternatively, a separate thermal regulator can be used, for example, positioned where heat is needed during module baking degassing, such as in one or more components absorbing water, to reduce degassing during sample evaluation. Cooling systems can be used to suppress thermal loads applied to thermistor components within the module. Cooling systems can include active and / or passive features. The conduits of the cooling system can be positioned to target components, such as detector arrays and electronics. The path of the conduit may be limited to applying cooling heat loads to such components. Therefore, heat can be applied and confined to the parts of the module that most require baking to degas in order to limit (if not prevent) degassing.

[0112] It should be noted that some designs of thermal regulators (such as heaters, e.g., resistance heaters) can be used as thermal sensors for temperature measurement when not being used as heaters. Therefore, heaters already present in existing components can be used to monitor the component's temperature, for example, as thermistor elements. A resistive element can operate as a heater when the controller determines that heat needs to be applied, either by the resistive element or another thermal sensor. Additionally or alternatively, the heater can be a separate heating element, such as one in contact with or integrated into the component. Since the heater can operate as a thermistor element, it can therefore operate in a similar manner when monitoring and applying heat.

[0113] The following is about Figure 7 The description can be used for the components of the charged particle system 40 of the present invention. Figure 7 This is a schematic diagram of the charged particle system 40. Figure 7 The charged particle system 40 may correspond to the charged particle system 40 mentioned above (also referred to as a device or tool). Unless otherwise stated, the features of the previously described embodiments are the same. Unless otherwise stated, the features, functions, benefits, and advantages of the invention described with reference to the earlier embodiments apply to this embodiment. Similarly, unless otherwise stated, reference to the embodiments (see reference...) Figure 7 The features, benefits, functions, and advantages described herein apply to the previously mentioned embodiments.

[0114] like Figure 7 As shown, a schematic diagram of an exemplary charged particle device has an objective lens array assembly. The objective lens array assembly includes an objective lens array 241. The objective lens array 241 includes a plurality of objectives. Each objective lens includes at least two electrodes (e.g., two or three electrodes) connected to a corresponding potential source. The objective lens array 241 may include two or more (e.g., three) plate electrode arrays connected to the corresponding potential sources. Each objective lens formed by the plate electrode array may be a microlens that operates on different sub-beams or groups of sub-beams in a plurality of beams. Each plate defines a plurality of apertures (also referred to as holes). The position of each aperture in a plate corresponds to the position of a corresponding aperture (or corresponding hole) in another plate (or plates). The corresponding apertures define the objective lens, so that each set of corresponding holes operates on the same sub-beam or group of sub-beams in the plurality of beams in use. Each objective lens projects a corresponding sub-beam of the plurality of beams onto sample 208.

[0115] The objective array assembly also includes a control lens array 250. The control lenses pre-focus the sub-beams (e.g., applying focusing to the sub-beams before they reach the objective array 241). Pre-focusing can reduce sub-beam divergence or increase sub-beam convergence. The control lens array and the objective array operate together to provide a combined focal length. Combined operation without an intermediate focal point reduces the risk of aberrations. In this embodiment, the control lens array can be considered part of the objective array.

[0116] exist Figure 7 In this arrangement, the objective array assembly includes a scanning deflector array 260. The scanning deflector array 260 includes a plurality of scanning deflectors. Each scanning deflector scans a corresponding sub-bundle over or across sample 208. Thus, the scanning deflector array 260 may include a scanning deflector for each sub-bundle. Each scanning deflector may deflect light in the sub-bundle in one direction (e.g., parallel to a single axis, such as the X-axis) or in two directions (e.g., relative to two non-parallel axes, such as the X and Y axes). Deflection causes the sub-bundle to be scanned across sample 208 along one or both directions (i.e., one-dimensionally or two-dimensionally). In embodiments, the scanning deflector described in EP2425444, which is incorporated herein by reference in its entirety, particularly with respect to the scanning deflector, may be used to implement the scanning deflector array 260. The scanning deflector array 260 is positioned between the objective array 241 and the control lens array 250. In the illustrated embodiment, a scan deflector array 260 is provided instead of a macro scan deflector, such as an electrostatic scan deflector (not shown). Compared to a macro scan deflector, the scan deflector array 260 can be more spatially compact.

[0117] The objective array assembly may include detector 240. (Alternatively, the detector may be included in the charged particle device 41 and does not necessarily have to be present in the objective array assembly.) Detector 240 may include detector elements (e.g., sensor elements, such as trapping electrodes). Detector 240 may include any suitable type of detector. For example, the detector element may be a charge-based detector configured to detect charge detected relative to time, such as as a current, a scintillator, or using a semiconductor device such as a PIN element. Detector 240 may be a DC detector or an indirect current detector.

[0118] Detector 240 can be positioned between objective array 241 and sample 208. Detector 240 is configured as the downstream feature of the electro-optical device's beam, for example, close to sample 208. Detector 240 can be very close to sample 208, for example, less than 5 mm, preferably between 200 and 10 µm.

[0119] Detector 240 can be positioned within the apparatus to face sample 208. Alternatively or additionally, detector 240 can be positioned elsewhere in the charged particle system 40 such that the portion of the charged particle device 41 facing sample 208 is different from the detector, and therefore not a detector; this portion is such as the electrodes of an objective lens arrangement. In such an arrangement, another element of the electron optics (e.g., the electrode plate of the objective lens) can face the sample during operation. In all these arrangements, the downstream element of the electron optics (such as detector 240) is closest to the sample. The downstream surface of the downstream element can face the sample.

[0120] The bottom surface of detector 240 (or the facing surface of detector 240 that may face sample 208 in use) may include a substrate on which a plurality of detector elements are provided. Each detector element may surround a beam aperture. The beam aperture may be formed by etching through the substrate. In an arrangement, the beam aperture is in a hexagonal close-packed array, or alternatively in a rectangular array. The detector elements may be arranged in a rectangular array or a hexagonal array.

[0121] In the cross-section of the detector, the detector element forms the bottommost (i.e., closest to sample 208) surface of detector 240. A logic layer may be provided between the detector element and the substrate body. At least a portion of the signal processing system may be incorporated into the logic layer. A wiring layer is provided on or inside the substrate and connected to the logic layer through substrate vias. The wiring layer may include control lines, data lines, and power lines. A printed circuit board and / or other semiconductor chips may be provided on the back side of detector 240, for example, connected to the back side of detector 240.

[0122] Detector 240 can be implemented by integrating a CMOS chip detector into the electrodes of objective array 241, such as the bottom electrode of objective array 241. Integrating detector 240 into objective array 241 or other components of charged particle system 41 allows for the detection of emitted electrons associated with multiple corresponding sub-beams. The CMOS chip can implement the detector, which can be oriented towards the sample. In an embodiment, detector elements for capturing secondary charged particles are formed in the top metal layer of the CMOS device. Detector elements can be formed in other layers. Power and control signals for the CMOS can be connected to the CMOS via through-silicon vias (TSVs). The passive silicon substrate with the vias shields the CMOS chip from high electric fields, providing robustness, for example.

[0123] To maximize detection efficiency, it is desirable to make the surface area of ​​the detector elements as large as possible, such that substantially all of the area of ​​objective array 240 (except for the aperture) is occupied by detector elements. Additionally or alternatively, the diameter of each detector element is substantially equal to the array pitch (i.e., the aperture pitch of the aperture array in the electrodes of objective assembly 241). The diameter of each detector element can be less than about 600 µm, and preferably between about 50 µm and 500 µm. The pitch can be selected based on the expected distance between sample 208 and detector 240. In embodiments, the detector elements are circular, but they can also be square to maximize the detection area. The diameter of the substrate via can be minimized. The typical size of the electron beam is about 5 to 15 µm.

[0124] In one embodiment, a single detector element surrounds each beam aperture. In another embodiment, multiple detector elements are provided around each beam aperture.

[0125] like Figure 7 As shown, the charged particle system 40 includes a vacuum system comprising multiple chambers. The chambers are defined by the inner surfaces of an outer wall 551 and an inner wall 552 of the vacuum system. Figure 7 The charged particle system 40 also includes a thermal control system, such as the one mentioned above. Figure 3 and Figure 4 A thermal control system as described. For example, Figure 7 The arrangement includes multiple heaters 510 associated with corresponding chambers of the vacuum system. For example... Figure 7 As shown, source 201 is provided in a separate chamber of the charged particle optical element of charged particle device 41. Figure 7 In the example arrangement shown, a condenser lens 231 is disposed in one chamber, and a collimator 235 is disposed in an adjacent chamber. A control lens array 250 and a detector 240 are disposed in the same chamber. A sample 208 can be provided on a sample holder or support, which can be included in another chamber. See reference... Figure 6Described, one or more components may be included in a module, which may be replaceable, e.g., field-replaceable. A thermal regulator may be incorporated into existing elements of such a module or may be additionally included within the module. The thermal regulator may be positioned, designed, and operated to optimize the baking degassing effect according to the requirements of one or more specific components of the module and to enable reliable operation of the charged particle system 40. The thermal regulator may be configured to achieve baking degassing without causing thermal effects (e.g., damage) on one or more sensitive elements of the module. Baking degassing can be achieved to suppress unwanted degassing during operation, e.g., driving degassing (i.e., fluids, e.g., gases) during baking degassing. Having a vacuum chamber designed for one or more of these modules, baking degassing can be achieved locally within the vacuum chamber or even locally within one of these components. By operating a thermal regulator associated with easily degassable components (e.g., support members (e.g., PCBs) or electrical connectors (e.g., cable flexures)), baking degassing can be locally achieved within components of such a module (e.g., localized baking degassing of such components). This application of the invention can be applied to components, e.g., referenced in [reference]. Figure 5 and 6 The modules arranged as shown and described.

[0126] Figure 8 A charged particle system 40 according to an embodiment is schematically depicted. Features identical to those described above are given the same reference numerals. For the sake of brevity, reference numerals are not further specified. Figure 8 This feature is described in detail. For example, source 201, condenser lens 231, macrocollimator 270, objective lens array 241, and sample 208 can be as described above. Unless stated to the contrary, the features, functions, benefits, and advantages of the invention described with reference to the earlier embodiments apply to this embodiment. Similarly, unless otherwise stated to the contrary, reference is made to the embodiments (see reference...). Figure 8 The features, benefits, functions, and advantages described herein apply to the previously mentioned embodiments.

[0127] As described above, in this embodiment, detector 240 is located between objective array 241 and sample 208. Detector 240 may face sample 208. Alternatively, as... Figure 8 As shown, in this embodiment, an objective array 241 comprising multiple objectives is located between detector 240 and sample 208. In addition to those described herein, detector 240 may have, for example, a previously referenced... Figure 7 All features of the described embodiments.

[0128] In one embodiment, the deflector array 95 is located between the detector 240 and the objective array 241. In another embodiment, the deflector array 95 includes a Wien filter (or even a Wien filter array), such that the deflector array can be referred to as a beam splitter. The deflector array 95 is configured to provide a magnetic field to separate charged particles projected onto the sample 208 from secondary electrons from the sample 208. However, it is preferred that the system includes electrostatic components rather than magnetic components.

[0129] In this embodiment, detector 240 is configured to detect signal particles by referencing the energy of charged particles, i.e., depending on the bandgap. Such a detector can be a semiconductor-based detector, such as a PIN detector or a scintillator (optically connected to a photon converter or photon-to-electron converter). This detector 240 can be referred to as an indirect current detector. Secondary electrons emitted from sample 208 gain energy from the field between the electrodes. The secondary electrodes have sufficient energy once they reach detector 240.

[0130] The control lens array 250 may exist in the same module as the objective lens array 241, i.e., forming an objective lens array assembly, or in another term, as part of the objective lens array, or it may be located in a separate module.

[0131] In, for example, reference Figure 7 , Figure 8 and Figure 9 Describe and Figure 7 , Figure 8 and Figure 9In some embodiments shown, one or more aberration correctors are provided to reduce one or more aberrations in a sub-beam. One or more aberration correctors may be provided in any embodiment, for example, as part of a charged particle optics device, and / or as part of an optical lens array assembly, and / or as part of an evaluation system, and / or as part of an electro-optics arrangement. In embodiments, at least each aberration corrector in a subset of aberration correctors is positioned in or directly adjacent to a corresponding intermediate focal point (e.g., in or adjacent to an intermediate image plane). The sub-beam has a minimum cross-sectional area in or near a focal plane such as an intermediate plane. This provides more space for the aberration correctors compared to space available elsewhere, i.e., upstream or downstream of the beam in the intermediate plane (or compared to space available in an alternative arrangement without an intermediate image plane). In different embodiments, the aberration correctors positioned in or directly adjacent to the intermediate focal point (or intermediate image plane) include deflectors for correcting source 201, which appears to be located differently for different beams. Correctors can be used to correct macro aberrations caused by the source, which prevent proper alignment between each sub-beam and its corresponding objective. In some embodiments, the aberration correctors are integrated with or directly adjacent to the objective array 241. In embodiments, these aberration correctors reduce one or more of the following: field curvature; focusing error; and astigmatism. The aberration correctors can be a standalone CMOS-based programmable deflector disclosed in EP2702595A1, or a multi-pole deflector array disclosed in EP2715768A2, both of which describe beam manipulators and are incorporated herein by reference.

[0132] Additionally or alternatively, one or more scanning deflectors (not shown) may be integrated with or directly adjacent to the objective array 241 for scanning sub-beams 211, 212, 213 over sample 208. In embodiments, the scanning deflectors described in US 2010 / 0276606 may be used, which is incorporated herein by reference in its entirety.

[0133] like Figure 2 As shown (when relative to) Figures 5 to 9(When read in the context of the depiction and description of the charged particle device 41), in an embodiment, the projection assembly 60 optionally includes an optical system 63. In an embodiment, the projection system 60 includes a light source 61. The light source 61 is configured to emit a light beam 62. As mentioned above, the projection assembly 60 is used to illuminate the sample 208 with the light beam 62 to control the charge accumulated due to effects such as photoconductivity, photoelectric, or thermal effects; thereby modulating the charge accumulated on the sample. In one arrangement, the light may be guided between the facing surface of the electro-optical device and the sample surface, for example by reflection from such surface, until it is incident on the sample at the same location as the primary beam. In one arrangement, the path of the light from the light source 61 may pass at least partially through the charged particle device 41. For example, the path of the light may enter the charged particle device upstream of the beam of the objective array 240 and be reflected toward the sample by a reflective surface 65 within the charged particle device 41, for example by an aperture defined in the plate defining the objective array and other charged particle optical elements of the charged particle device. In one embodiment, the light source may be close to source 201, such as around and / or adjacent to source 201, such that the path of light toward the sample passes through all elements of the charged particle device 41. In another embodiment, the path of light is via a light guide from the light source to the objective lens array, as disclosed, for example, in EP 22204243.4, filed October 27, 2022, which is incorporated herein by reference, at least with respect to the disclosure of an optical light guide used for outward coupling of light toward the sample. Additionally or alternatively, light may be coupled outward near or from an aperture defined in the sample-facing surface of the element.

[0134] like Figure 8 As shown, the charged particle system 40 includes a vacuum system comprising multiple chambers. The chambers are defined by the inner surfaces of an outer wall 551 and an inner wall 552 of the vacuum system. Figure 8 The charged particle system 40 also includes a thermal control system, such as the one mentioned above. Figure 3 and Figure 4 A thermal control system as described. For example, Figure 8 The arrangement includes multiple heaters 510 associated with corresponding chambers of the vacuum system. For example... Figure 8 As shown, source 201 is provided in a separate chamber of the charged particle optical element of charged particle device 41. Figure 8 In the example arrangement shown, the condenser lens 231 and macrocollimator 270 are disposed in the same chamber, and the detector 240 is disposed in an adjacent chamber. The deflector array 95 is disposed in another chamber, and the objective lens array 241 is disposed in yet another chamber. The sample 208 may be provided on a sample holder or support, which may be included in another chamber.

[0135] refer to Figure 8The arrangement shown and described may have one or more electrical components, which may be located in accordance with Figure 5 , 6 The corresponding modules described in section 7, concerning the charged particle system, may include the features described herein and operate in the manner described herein to achieve... Figure 8 The localized baking and degassing of a portion of the charged particle system shown.

[0136] The charged particle system 40 may include multiple sources 201, such as Figure 9 and Figure 10 As shown. Unless otherwise stated, the features, functions, benefits, and advantages of the invention described with reference to the earlier embodiments apply to this embodiment. Similarly, unless otherwise stated, reference is made to the embodiments (see reference). Figure 9 and Figure 10 The features, benefits, functions, and advantages described herein apply to the previously mentioned embodiments. As stated above, Figure 9 The arrangement shown is a charged particle system comprising multiple charged particle devices 41, each charged particle device having a corresponding source 201. (In different embodiments, the charged particle device 41 may include a corresponding source 201). The charged particle device 41 may be a reference. Figure 5 , Figure 7 and Figure 8 Any charged particle device shown or depicted. However, Figure 9 The layout and reference shown Figure 5 The arrangement shown and described is similar, with a collimator array and a scanning deflector array close to and integrated with the objective lens array and the control lens array, for example.

[0137] Each source 201 is configured to emit a corresponding beam of charged particles. Figure 9 and Figure 10 The charged particle system 40 includes a corresponding charged particle device 41 for each corresponding source 201. The charged particle system includes walls between chambers adjacent to the electron optics device. Specifically, in Figure 9 and Figure 10In the arrangement shown, the wall between the chambers of adjacent electron optical devices is an inner wall 552. The inner wall 551 can define different chambers for the respective charged particle devices 41. It is desirable that a thermal shield exists between each of the multiple sources 201 in the charged particle system 40. Therefore, a thermal shield may exist between a source 201 and its corresponding charged particle device. Additionally or alternatively, a thermal shield may exist between the chambers of adjacent charged particle devices 41. In other words, a thermal shield may exist between a source 201 and an adjacent source 201, and between the charged particle devices 41 associated with an adjacent source 201. The thermal shield may be provided by the inner wall 552. The sources 201 can be respectively disposed in different chambers.

[0138] refer to Figure 9 and Figure 10 The arrangement shown and described may have one or more electrical components, which may be located in the reference Figure 5 , 6 The corresponding modules described in the charged particle systems of 7 and 8. Such components and modules (if present) may include the features described herein and operate in the manner described herein to achieve Figure 9 The localized baking and degassing of a portion of the charged particle system shown.

[0139] In an embodiment, the charged particle device 41 may include alternative and / or additional components along the charged particle path, such as lenses and other components, some of which have been previously referenced. Figure 1 and 6 It has been described. Figure 9 An example of this arrangement is shown below, and will be described in further detail later. A detector is provided to detect charged particles emitted from the sample. The detector can be integrated into the objective lens. The detector can be located on the bottom surface of the objective lens so that it faces the sample during use. The detector can include, for example, an array of detector elements, which may correspond to a beam array arranged in multiple beams. The detectors (or detector elements) in the detector array can generate detection signals that can be associated with pixels of the generated image.

[0140] Figure 9 This is a schematic diagram of another design including multiple exemplary charged particle optical devices 41. Each charged particle device 41 may include a source 201 and one or more electro-optical components. Alternatively, the electro-optical device including the charged particle device 41 may include the source 201. The charged particle device 41 may include an upper beam limiter 252, a collimator element array 271, a control lens array 250, a scanning deflector array 260, an objective lens array 241, a beam shaping limiter 242, and a detector array. The source 201 provides a beam of charged particles (e.g., electrons). These components may be incorporated into a reference electronics device 41 (reference...). Figure 5 ,6 The form described in Figure 7 and the description.

[0141] A collimator element array 271 is provided downstream of the beam from the upper collimator 252. Each collimator element collimates a corresponding sub-beam. The collimator element array 271 can be formed using various processing techniques to achieve a compact footprint. In some embodiments, such as... Figure 9 As illustrated, the collimator element array 271 is the first deflection or focusing electro-optical array element in the beam path downstream of the beam of source 201.

[0142] In an embodiment, such as Figure 9 The illustration provides an array 500 of charged particle optical devices. Array 500 may include a plurality of any charged particle optical devices described herein. Each charged particle optical device in the array simultaneously focuses corresponding multiple beams onto different regions of the same sample.

[0143] Any number of charged particle optics can be used in array 500. Each charged particle optic in array 500 can be configured in any of the ways described herein when referring to a single charged particle optic. Details of this arrangement are described in EPA 20184161.6, filed July 6, 2020, regarding how objectives are incorporated and applicable to multi-instrument arrangements, which is incorporated herein by reference.

[0144] like Figure 9 As shown, the charged particle system 40 includes a vacuum system comprising multiple chambers. The chambers are defined by the inner surfaces of an outer wall 551 and an inner wall 552 of the vacuum system. Figure 9 The charged particle system 40 also includes a thermal control system, such as the one mentioned above. Figure 3 and Figure 4 A thermal control system as described. For example, Figure 9 The arrangement includes multiple heaters 510 associated with corresponding chambers of the vacuum system. For example... Figure 9 As shown, source 201 is provided in a separate chamber of the charged particle optical element of charged particle device 41. Figure 9In the example arrangement shown, sources 201 are all provided in the same chamber, with inner walls separating the beams emitted from each source 201. In an alternative arrangement, inner wall 552 may extend to outer wall 511. In other words, in an alternative arrangement, each source 201 may be provided in a separate chamber of the vacuum system. The chamber housing the sources 201 desirably includes multiple heaters. In particular, at least one heater may be provided to heat each source 201 during bake-out degassing. The walls of the chamber housing the sources 201 may optionally include or be composed of a getter material (e.g., these walls effectively provide a pump for maintaining a vacuum in the chamber). Components of each charged particle device 41 may be provided in one or more separate chambers. In other words, components of each charged particle device 41 may have one or more dedicated chambers that are not shared with other charged particle devices 41 of the charged particle system 40. Each charged particle device 41 may be associated with a corresponding source 201.

[0145] Figure 10 A side view (such as a cross-section along the beam path or electron optical axis) of a charged particle system 40 including charged particle devices 41 (or more devices) is provided. As an exemplary arrangement, Figure 10 The charged particle system 40 provides an arrangement of four beam regions, which are arranged in two rows of two beam regions. Figure 10 The charged particle system 40 includes multiple charged particle beam sources 201. Figure 10 The charged particle system 40 includes four sources 201 (two of which are visible). The walls defining the vacuum chamber including the modules can be integrated into modules such as source array modules. Such source array modules can be replaceable. Different charged particle devices 41 may include collimators 235, condenser lens arrays 231, and objective lens arrays 241. The collimator is configured to collimate the beam of a beam grating, for example, collimating a diverging beam array from the condenser lens array 231 into a collimated beam toward the sample. As mentioned, the charged particle device includes, for example, a reference... Figure 5 , Figure 7 and Figure 8 The described and illustrated electro-optical components or variations thereof.

[0146] like Figure 10 As shown, the charged particle system 40 includes a vacuum system comprising multiple chambers. The chambers are defined by the inner surfaces of an outer wall 551 and an inner wall 552 of the vacuum system. Figure 10 The charged particle system 40 also includes a thermal control system, such as the one mentioned above. Figure 3 and Figure 4 A thermal control system as described. For example, Figure 10 The arrangement includes multiple heaters 510 associated with corresponding chambers of the vacuum system. For example... Figure 10As shown, each source 201 can be provided in a separate chamber. The inner wall 552 can separate the different sources 201 of the charged particle system 40. The individual chambers can be operated in groups or individually to achieve localized baking and degassing, for example, as shown in the reference... Figures 5 to 8 Each and every accompanying drawing in the figure is described in the manner in which they are depicted. Localized baking and degassing of components and / or specific chambers can be referenced. Figure 9 and Figure 10 It is implemented in the charged particle device shown and described.

[0147] Although the disclosure herein may appear to be limited to systems in which multiple beams are simultaneously directed to a sample (e.g., multi-beam evaluation systems), the invention is applicable to single-beam systems. Such a single-beam system may include a source, a condenser lens, a detector, a scanning deflector, and an objective lens, as well as other electro-optical elements, such as a corrector. The single-beam system may have a reference... Figure 6 The charged particle evaluation system shown and described uses similar electron optical components and architecture, except, for example, it has a single beam without components for individually generating and / or operating different beams, such as a source converter for multiple beams. The charged particle system may have one or more chambers in which the electron optical components can be locally baked degassed using thermal shielding with thermal regulators (such as cooling elements and heaters) described herein. Furthermore, in the case of multiple chambers, different parts (e.g., different components) of the charged particle device can be locally baked degassed. This baking degassed process can help manage and suppress contamination, such as degassing. This baking degassed process can avoid applying excessive thermal loads to sensitive components, for example, extending their lifespan.

[0148] In this document, reference is made to an electro-optical plate with one or more apertures. Such a plate can be fabricated using processes suitable for manufacturing microelectromechanical systems (MEMS). Such charged particle optical components or devices can be referred to as MEMS. MEMS are miniaturized mechanical and electromechanical components fabricated using microfabrication techniques. The pre-bending deflector array 323 can be a MEMS. In embodiments, the charged particle device 41 includes apertures, lenses, and deflectors that can be formed as MEMS features, such as condenser lens arrays, control lens arrays, objective lens arrays, collimator arrays, scanning deflector arrays, corrector arrays, and even detector arrays. Other such electro-optical elements, such as condenser lenses, objectives, and / or detectors, can be formed as MEMS or CMOS devices.

[0149] One or more power sources can be provided as the power supply for the electro-optical elements of each component and element of the different charged particle systems disclosed herein. Potentials can be applied to different electrodes of different electrostatic elements. Current can be applied to the mentioned magnetic components. Such components and elements include, for example: macro-condenser lenses, sources, scanning deflectors, detectors, electrodes of control lenses in control lens array 250, objectives in objective lens array 241, elements of collimator arrays, lenses of condenser lens arrays, scanning deflector arrays, and corrector elements.

[0150] The above description is intended to be illustrative and not restrictive. Therefore, it will be apparent to those skilled in the art that modifications may be made as described without departing from the scope of the claims and terms set forth below.

[0151] Although the invention has been described in conjunction with various embodiments, other embodiments of the invention will be apparent to those skilled in the art from the description and practice of the invention disclosed herein. The description and examples are intended to be illustrative only, and the true scope and spirit of the invention are indicated by the following claims and terms.

[0152] The following terms were provided:

[0153] Clause 1. A charged particle system for emitting a beam of charged particles toward a sample to examine the sample, the system comprising: a source configured to emit the beam of charged particles; a charged particle device configured to project the beam of charged particles toward the sample, the charged particle device including a plurality of charged particle optical elements along a path of the charged particle beam; a support configured to support the sample; a vacuum system having a plurality of chambers, wherein different chambers are configured to include at least one corresponding component, the at least one corresponding component including the source and at least one of the one or more charged particle optical elements; and a thermal control system configured to independently bake and degas the different chambers.

[0154] Clause 2. The system according to Clause 1, wherein the thermal control system includes a thermal regulator, such as a heater associated with a corresponding chamber of the vacuum system.

[0155] Clause 3. The system according to Clause 2, wherein the heater is directly connected to the chamber of the vacuum system, for example, at least partially connected to the wall of the chamber, desirably defining the wall of the corresponding chamber as at least a portion of the outer wall of the vacuum system, desirably the outer wall being between an external environment and a vacuum environment including at least one corresponding component.

[0156] Clause 4. The system according to Clause 2 or 3, wherein the heater is disposed within the interior space of the corresponding chamber of the vacuum system, and the interior is desirously defined at least in part by the inner surface of the wall (e.g., inner wall) defining the corresponding chamber.

[0157] Clause 5. The system according to any one of Clauses 2 to 4, wherein the heater is at least partially embedded within the wall of the corresponding chamber defining the vacuum system.

[0158] Clause 6. The system according to Clause 5, wherein the heater is flush with the inner surface of the wall of the corresponding chamber defining the vacuum system.

[0159] Clause 7. The system according to Clause 5, wherein the heater is fully embedded within the wall of the corresponding chamber defining the vacuum system.

[0160] Clause 8. The system according to any one of Clauses 5 to 7, wherein the wall defining the corresponding chamber is the outer wall of the vacuum system, and the outer wall is preferably located between an external environment and a vacuum environment including at least one corresponding component.

[0161] Clause 9. The system according to any one of Clauses 5 to 7, wherein the wall defining the corresponding chamber is the inner wall of the vacuum system, and the inner wall is desired between the vacuum environments of the different chambers, each comprising at least one corresponding component.

[0162] Clause 10. The system according to Clause 9, wherein the inner wall separates the two different chambers of the vacuum system.

[0163] Clause 11. The system according to any one of Clauses 2 to 10, wherein the heater is configured to heat at least a portion of at least one corresponding component in the corresponding chamber, wherein at least a portion of at least one corresponding component is preferably heat-resistant.

[0164] Clause 12. The system according to Clause 11, wherein the thermal control system includes a thermal sensor, which is preferably configured to thermally sense the temperature of at least a portion of the respective component.

[0165] Clause 13. A system according to any one of Clauses 11 and 12, wherein at least one corresponding component comprises at least one of the following: the source, the support, and at least one charged particle optical element.

[0166] Clause 14. A system according to any one of Clauses 2 to 13, wherein the thermal control system includes a thermal sensor, which is preferably configured to thermally sense the temperature of the thermal regulator, such as the heater.

[0167] Clause 15. The system according to any one of Clauses 2 to 14, wherein the thermal control system includes a thermal controller configured to control the thermal regulator.

[0168] Clause 16. A system pursuant to Clause 15, for example when it is subordinate to Clause 12 or 14, wherein the controller is configured to apply thermal control to achieve the baking degassing, desirably by controlling the thermal regulator, desirably based on the thermal signal from the thermal sensor.

[0169] Clause 17. The system according to any one of Clauses 15 to 16, wherein the thermal control system comprises a plurality of respective independently controllable thermal regulators, and preferably the plurality of respective independently controllable thermal regulators comprise a plurality of respective independently controllable heaters.

[0170] Clause 18. The system according to Clause 17, wherein the plurality of said chambers includes a first chamber and a second chamber, wherein the plurality of respective independently controllable heaters includes a first respective independently controllable heater associated with the first chamber and a second respective independently controllable heater associated with the second chamber.

[0171] Clause 19. The system according to Clause 18, wherein the thermal controller is configured to independently control the first corresponding independently controllable heater to achieve the baking degassing in the first chamber, wherein a vacuum is desired to be maintained in the first chamber during the baking degassing.

[0172] Clause 20. The system according to Clause 18 or 19, wherein the thermal controller is configured to independently control the second corresponding independently controllable heater to achieve the baking degassing in the second chamber, wherein a vacuum is desired to be maintained in the second chamber during the baking degassing.

[0173] Clause 21. The system according to Clause 19 or 20, wherein the thermal control system is configured such that the baking degassing is performed locally in the chamber associated with a corresponding independently controllable heater configured to achieve the baking degassing.

[0174] Clause 22. The system according to Clause 21, wherein a corresponding independently controllable heater is configured to apply heat to locally bake and degas a component, the component being disposed in a chamber associated with the corresponding independently controllable heater configured to perform the baking and degassing.

[0175] Clause 23. The system according to any one of Clauses 18 to 22, wherein the thermal controller is configured to independently control each of a plurality of respective independently controllable heaters.

[0176] Clause 24. The system according to any one of Clauses 2 to 23, wherein the thermal regulator is a heater, wherein the heater includes a resistive element, preferably a resistive trace.

[0177] Clause 25. The system according to any one of the preceding clauses, wherein the vacuum system includes a thermal shield between the different chambers.

[0178] Clause 26. The system according to Clause 25, wherein the inner wall of the vacuum system is configured to separate and thermally shield the different chambers.

[0179] Clause 27. The system according to any one of the preceding clauses, wherein the source and the one or more charged particle optical elements are located in different chambers.

[0180] Clause 28. The system according to any one of the preceding clauses further includes a valve between different adjacent chambers, which is desirously closed when the thermal regulator is operated in at least one of the adjacent chambers.

[0181] Clause 29. The system according to any one of the preceding clauses, wherein the charged particle device is configured to convert the charged particle beam emitted from the source into a plurality of sub-beams and to direct each sub-beam toward the sample.

[0182] Clause 30. A system according to any one of the preceding clauses includes a plurality of sources, wherein each source is configured to emit a corresponding beam of charged particles, and the system preferably includes a corresponding charged particle device for each corresponding source, wherein the wall between the chambers adjacent to the electron optical device preferably is an inner wall.

[0183] Clause 31. The system according to Clause 30 further includes a thermal shield between each source and / or between the chambers adjacent to the electro-optical devices.

[0184] Clause 32. The system according to Clause 31, wherein the sources are respectively disposed in the different chambers.

[0185] Clause 33. The system according to any one of the preceding clauses, wherein the vacuum system is configured to bake degassing during evacuation, for example, at least selectively, in the chamber corresponding to the heater.

[0186] Clause 34. A method for baking and degassing a charged particle system, wherein the charged particle system comprises: a source configured to emit a charged particle beam; a charged particle device configured to project the charged particle beam toward a sample, the charged particle device including a plurality of charged particle optical elements along a path of the charged particle beam; a vacuum system having a plurality of chambers, wherein the different chambers include at least one corresponding component, the at least one corresponding component including the source and at least one of the one or more charged particle optical elements; and a thermal control system configured to bake and degas the different chambers; wherein the method includes controlling the thermal control system to bake and degas the different chambers independently.

[0187] Clause 35. A method for baking and degassing a charged particle system, the charged particle system comprising a plurality of vacuum chambers each including different components of the charged particle system and a heat regulator associated with each component for thermally regulating at least a portion of the respective component, the method comprising: controlling the heat regulator to heat at least a portion of the respective component of the charged particle system such that the different heat regulators operate independently of each other to bake and degas the respective component.

[0188] Clause 36. The method according to Clause 35, wherein the thermal regulation of the different thermal regulators occurs in the different chambers, desiccating the baking process in the different chambers independently of each other.

[0189] Clause 37. The method according to Clause 35 or 36, wherein the charged particle system includes a valve between adjacent vacuum chambers, wherein the method includes closing the valve between adjacent chambers when at least one of the adjacent chambers includes a component undergoing the baking degassing.

[0190] Clause 38. The method according to any one of Clauses 35 to 37, wherein the charged particle system includes a thermal sensor system for monitoring different parts of the charged particle system, and the method includes receiving a monitoring signal from the thermal sensor system, wherein control of the thermal regulator is based on the received monitoring signal.

[0191] Clause 39. The method according to Clause 38, wherein the sensor system includes a thermal sensor associated with the respective component and / or the thermal regulator, and the method further includes sending a monitoring signal from the respective thermal sensor, wherein desired control includes controlling the respective thermal regulator based on the monitoring signal from the respective thermal sensor.

[0192] Clause 40. The method according to any one of Clauses 34 to 39, wherein the charged particle system is a charged particle system according to any one of Clauses 1 to 33.

Claims

1. A charged particle system for firing a beam of charged particles toward a sample to examine the sample, the system comprising: The source is configured to emit a beam of charged particles; A charged particle device is configured to project the charged particle beam toward a sample, the charged particle device including a plurality of charged particle optical elements along the path of the charged particle beam; A support element is configured to support the sample; A vacuum system having multiple chambers, wherein different chambers are configured to include at least one corresponding component, said at least one corresponding component including the source and at least one of one or more charged particle optical elements; and The thermal control system is configured to independently bake and degas the different chambers.

2. The system of claim 1, wherein the thermal control system includes a heater associated with a corresponding chamber of the vacuum system.

3. The system of claim 2, wherein the heater is directly connected to the wall of the chamber.

4. The system according to claim 2 or 3, wherein the heater is disposed within the internal space of the corresponding chamber of the vacuum system.

5. The system of claim 4, wherein the wall defining the corresponding chamber is the inner wall of the vacuum system.

6. The system according to any one of claims 2 to 5, wherein the heater is configured to heat at least a portion of at least one corresponding component in the corresponding chamber.

7. The system of claim 6, wherein the heater includes a thermal sensor for determining the temperature of at least a portion of the respective component.

8. The system according to any one of claims 2 to 7, wherein the thermal control system includes a thermal controller configured to control the heater to achieve baking and degassing.

9. The system of claim 8, wherein the thermal control system comprises a plurality of respective independently controllable heaters.

10. The system of claim 9, wherein the plurality of chambers includes a first chamber and a second chamber, wherein the plurality of respective independently controllable heaters includes a first respective independently controllable heater associated with the first chamber and a second respective independently controllable heater associated with the second chamber.

11. The system according to any one of claims 2 to 10, wherein the heater comprises a resistive element.

12. The system according to any one of the preceding claims, wherein the vacuum system includes a thermal shield between the different chambers.

13. The system according to any one of the preceding claims further includes a valve between different adjacent chambers.

14. The system according to any one of the preceding claims, wherein the vacuum system is configured to bake degassing during evacuation.

15. A method for baking and degassing a charged particle system, the charged particle system comprising a plurality of vacuum chambers each including different components of the charged particle system and a heater associated with each component for thermal conditioning at least a portion of the respective component, the method comprising: The heater is controlled to heat at least a portion of the corresponding component of the charged particle system, such that different heaters operate independently of each other to bake and degas the corresponding component.

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