Detector module comprising printed circuit board for sealing vacuum chamber

Abstract

To disclose detector modules, systems, and methods for detecting signal beams using a detector module and a support comprising a feedthrough and to disclose apparatuses, systems, and methods for sealing a vacuum system configured to provide an atmospheric environment and a vacuum chamber environment.SOLUTION: In some embodiments, a printed circuit board (PCB) comprises a first side for exposing to an atmospheric environment and a second side for exposing to a vacuum chamber environment and for covering an aperture in the vacuum chamber environment, where the second side is opposite to the first side. Apparatuses, systems, and methods may include a rigid body on the first side of the PCB and a device connected to the second side of the PCB and positioned on a portion of the PCB that covers the aperture. The PCB may be configured to provide an interface between the device and the rigid body.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Patent Application No. 63 / 068,880, filed August 21, 2020, and U.S. Patent Application No. 63 / 184,067, filed May 4, 2021, each of which is incorporated by reference in its entirety into this specification.

[0002]

[0002] The description herein relates to the field of detector modules, and more particularly to a detector module that can be used to define at least a portion of a wall of a vacuum chamber of an evaluation tool. Furthermore, the description herein relates to the field of charged particle beam systems, and more particularly to a system for sealing a vacuum system using a printed circuit board in a charged particle beam inspection system. [Background technology]

[0003]

[0003] During the integrated circuit (IC) manufacturing process, unfinished and finished circuit components are inspected to ensure they are manufactured as designed and are free of defects. Inspection systems based on optical microscopes typically have a resolution of up to a few hundred nanometers, limited by the wavelength of light. As the physical dimensions of IC components continue to shrink to below 100 nanometers and even below 10 nanometers, inspection systems with higher resolution than those based on optical microscopes are required.

[0004]

[0004] Charged particle (electron) beam microscopes, such as scanning electron microscopes (SEMs) or transmission electron microscopes (TEMs), with sub-nanometer resolution, serve as practical tools for inspecting IC components with feature sizes of 100 nanometers or less. In an SEM, electrons from a single primary electron beam or multiple primary electron beams can be focused onto a location of interest on a wafer being inspected. The primary electrons can interact with the wafer and be backscattered, or can cause the wafer to emit secondary electrons. The intensity of the electron beam, including the backscattered and secondary electrons, can vary based on the characteristics of the wafer's internal and external structure, thereby indicating whether the wafer is defective. Summary of the Invention

[0005]

[0005] According to one aspect of the present invention, there is provided a detector module for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool, the detector being configured to operate within the vacuum chamber and configured to be alignable with an incidental charged particle beam path; and a support for defining at least a portion of the wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough, and an applied disturbance causing the support to deform, the support being configured such that in the presence of disturbances to the detector and / or the support the position of the detector during operation of the detector is maintained relative to the incidental charged particle beam path.

[0006]

[0006] According to one aspect of the present invention, there is provided a detector module including: a detector module for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool, the detector being configured to operate within the vacuum chamber and configured to be alignable with an incident charged particle beam path; a support for defining at least a portion of the wall of the vacuum chamber, the support including a feedthrough to which the detector is attached and the detector is electrically connected through the feedthrough; a thermal conditioning system including a support thermal conditioning section configured to thermally condition the support and a further thermal conditioning section configured to thermally condition another portion of the detector module; and a detachable portion including the other portion and the further thermal conditioning section, the detachable portion configured to be removable from the detector module.

[0007]

[0007] According to one aspect of the present invention, there is provided a detector module including: a detector module for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool, the detector configured to operate within the vacuum chamber and configured to be alignable with an incident charged particle beam path; a support for defining at least a portion of the wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough; and an electric shield configured to shield at least a portion of the detector module from electric fields, the electric shield attached to the support such that during operation, when an external disturbance that deforms the support is applied, the portion of the detector module that is shielded by the electric shield is maintained.

[0008]

[0008] According to one aspect of the present invention, there is provided a method for detecting an incidental charged particle beam in a charged particle beam inspection tool, the method comprising: a) providing a detector module, the detector module including a detector configured to be alignable with the incidental charged particle beam path; and a support for defining at least a portion of a wall of a vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough, and an applied disturbance causing the support to deform, the detector module being configured such that in the presence of disturbances to the detector and / or the support, the position of the detector is maintained relative to the incidental charged particle beam path during operation of the detector; b) providing a vacuum environment around the detector; and c) providing the incidental charged particle beam for detection by the detector.

[0009]

[0009] According to one aspect of the present invention, there is provided a method for detecting an incidental charged particle beam in a charged particle beam inspection tool, the method comprising: a) providing a detector module, the detector module comprising: a detector configured to operate within a vacuum chamber and configured to be alignable with an incidental charged particle beam path; a support for defining at least a portion of a wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough; a thermal conditioning system including a support thermal conditioning section configured to thermally condition the support and a further thermal conditioning section configured to thermally condition another portion of the detector module; and a detachable portion including the other portion and the further thermal conditioning section, the detachable portion configured to be removable from the detector module; b) providing a fluid to the support thermal conditioning section and the further thermal conditioning section; c) providing a vacuum environment around the detector; and d) providing the incidental charged particle beam for detection by the detector.

[0010]

[0010] According to one aspect of the present invention, there is provided a method for detecting an incidental charged particle beam in a charged particle beam inspection tool, the method comprising: a) providing a detector module, the detector module being a detector configured to operate within a vacuum chamber and configured to be alignable with an incidental charged particle beam path; a support for defining at least a portion of a wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough; and an electric shield configured to shield at least a portion of the detector module from electric fields, the electric shield being attached to the support such that during operation, under the application of an external disturbance that deforms the support, the portion of the detector module that is shielded by the shield is maintained; b) providing a vacuum environment around the detector; and c) providing the incidental charged particle beam for detection by the detector.

[0011] According to one aspect of the present invention, there is provided a method for detecting an incident charged particle beam using a detector module according to the appended claims.

[0012]

[0012] Furthermore, embodiments of the present disclosure provide apparatus, systems, and methods for sealing a vacuum system configured to provide an atmospheric environment and a vacuum chamber environment. In some embodiments, a printed circuit board (PCB) can include a first side for exposure to the atmospheric environment and a second side for exposure to the vacuum chamber environment and covering an aperture in the vacuum chamber environment, the second side being opposite the first side. The system can include a rigid body on the first side of the PCB and a device connected to the second side of the PCB and positioned on a portion of the PCB covering the aperture. The PCB can be configured to provide an interface between the device and the rigid body.

[0013] In some embodiments, a method of sealing a vacuum system configured to provide an atmospheric environment and a vacuum chamber environment can include using a PCB to provide an interface between a device and a rigid body. The PCB can include a first side for exposure to the atmospheric environment and a second side for exposure to the vacuum chamber environment and covering an aperture in the vacuum chamber environment, the second side being opposite the first side. The rigid body can be on the first side of the PCB, and the device can be connected to the second side of the PCB and positioned on a portion of the PCB covering the aperture. The method can include operating the device in the vacuum system.

[0014]

[0014] The above and other aspects of the present disclosure will become more apparent from the following description of the embodiments read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram illustrating an exemplary electron beam inspection (EBI) system consistent with an embodiment of the present disclosure. [Figure 2]

[0016] 2 is a schematic diagram illustrating an example multi-beam electron optical column that may be part of the example electron beam inspection system of FIG. 1. [Figure 3]

[0017] 2 is a schematic diagram illustrating an example multi-beam system that is part of the example charged particle beam inspection system of FIG. 1, consistent with an embodiment of the present disclosure. [Figure 4A]

[0018] FIG. 1 is a schematic diagram illustrating a detector module consistent with an embodiment of the present disclosure. [Figure 4B] 1 is a schematic diagram illustrating an exemplary elastic member. [Figure 5]

[0019] FIG. 4 is a schematic diagram illustrating an example vacuum system that is part of the example multi-beam system of FIGS. 2 and / or 3, consistent with an embodiment of the present disclosure. [Figure 6]

[0020] 1 is a flowchart of an exemplary process for sealing a vacuum system consistent with embodiments of the present disclosure. [Figure 7]

[0021] FIG. 1 is a schematic diagram illustrating a detector module consistent with an embodiment of the present disclosure. [Figure 8A]

[0022] 8 is a schematic diagram showing a cross section through a detector module as shown in FIG. 7 depicting a variation of the detector module consistent with an embodiment of the present disclosure. [Figure 8B] FIG. 8 is a schematic diagram showing a cross section through a detector module as shown in FIG. 7, depicting a variation of the detector module consistent with an embodiment of the present disclosure. [Figure 9A]

[0023] FIG. 8 is a schematic diagram showing a cross section through a detector module as shown in FIG. 7, consistent with an embodiment of the present disclosure. [Figure 9B] FIG. 8 is a schematic diagram showing a cross section through a detector module as shown in FIG. 7, consistent with an embodiment of the present disclosure. [Figure 10A]

[0024] FIG. 1 is a schematic diagram illustrating a detector module consistent with an embodiment of the present disclosure. [Figure 10B] FIG. 10B is a schematic diagram showing details of the detector module depicted in FIG. 10A, consistent with an embodiment of the present disclosure. [Figure 10C] FIG. 10B is a schematic diagram showing details of the detector module depicted in FIG. 10A, consistent with an embodiment of the present disclosure. [Figure 10D] FIG. 10B is a schematic diagram showing details of the detector module depicted in FIG. 10A, consistent with an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016]

[0025] These schematic diagrams and representations show the components described below, however, the components in these figures are not drawn to scale.

[0017]

[0026] 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, in which like numbers in different drawings represent the same or similar elements unless otherwise specified. The implementations described in the following description of exemplary embodiments do not represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with aspects related to the subject matter recited in the appended claims. For example, although some embodiments are described in connection with the use of electron beams, the present disclosure is not limited thereto. Other types of charged particle beams may be similarly applied. The terms charged particle and electron are used interchangeably herein. Additionally, other imaging systems may be used, such as optical imaging, light detection, x-ray detection, extreme ultraviolet inspection, deep ultraviolet inspection, etc.

[0018]

[0027] An electronic device is a structure in which circuits are formed on a piece of silicon called a substrate. Many circuits can be formed on the same piece of silicon, and many circuits are called integrated circuits (ICs). The size of these circuits is shrinking dramatically to allow more circuits to fit on the substrate. For example, the IC chip in a smartphone may be about the size of a thumbnail, but may contain over 2 billion transistors, each less than 1 / 1000 the size of a human hair.

[0019]

[0028] Manufacturing these tiny ICs is a complex, time-consuming, and costly process, often involving hundreds of individual steps. An error in any one step can cause the finished IC to be defective and render it unusable. Therefore, one goal of the manufacturing process is to avoid such defects and maximize the number of functional ICs produced by the process, i.e., to improve the overall yield of the process.

[0020]

[0029] One factor in improving yield is monitoring the chip manufacturing process to ensure it is producing a sufficient number of functional integrated circuits. One way to monitor the process is to inspect the chip circuit structures at various stages of their formation. Inspection can be done using a scanning electron microscope (SEM). An SEM allows for imaging of these very small structures, effectively taking a "picture" of the structures on the wafer. This image can be used to determine if the structures are formed properly and in the correct location. If the structures are defective, the process can be adjusted to make the defect less likely to recur.

[0021]

[0030] The operating principle of an SEM is similar to that of a camera. A camera takes pictures by receiving and recording the brightness and color of light reflected or emitted from a person or object. An SEM takes "pictures" by receiving and recording the energy or quantity of electrons reflected or emitted from a structure. Before taking such a "picture," an electron beam may be provided to the structure. As electrons reflect or are emitted ("emit") from the structure, the SEM's detector receives and records the electron energy or quantity, generating an image. To take such "pictures," some SEMs use a single electron beam (called a "single-beam SEM"), while others use multiple electron beams (called a "multi-beam SEM") to take multiple "photographs" of the wafer. By using multiple electron beams, the SEM can provide more electron beams to the structure to obtain these multiple "photos," resulting in more electrons exiting the structure. Thus, the detector can simultaneously receive more exiting electrons and generate images of the wafer's structures with greater efficiency and speed.

[0022]

[0031] SEMs may operate in a vacuum chamber environment. For example, during high-temperature processes (e.g., bakeout), SEMs may operate in a high-temperature and vacuum chamber environment to remove fluids or gases from the vacuum chamber environment. However, when an SEM includes or operates in a vacuum environment, water vapor or air molecules leak from other system components into the vacuum chamber, which can be undesirable for a number of reasons. One reason is that the leaks can cause the vacuum chamber to take longer to reach a predetermined pressure before wafer inspection can occur, slowing throughput or even preventing the vacuum chamber from reaching the predetermined pressure. For example, a poor seal between the atmospheric environment and the vacuum environment can allow water vapor or air molecules to leak from the atmospheric environment. If water vapor or air molecules leak into the vacuum chamber, the pressure in the vacuum chamber can increase, preventing the vacuum chamber from reaching the predetermined pressure required for inspection. Thus, an increase in the time it takes for the system to reach the predetermined pressure (e.g., pump-down time) can reduce system availability.

[0023]

[0032] Additionally, water vapor and air molecules can reduce the lifespan of the inspection system due to components within the system that are sensitive to such contaminants (e.g., pure aluminum components, high voltage components, charged particle source components, etc.). Therefore, the ability to prevent water vapor and air molecules from entering the vacuum chamber is important to improving the throughput and lifespan of the inspection system. The type of seal between the atmospheric environment and the vacuum environment can be important to prevent fluids and gases from entering the vacuum environment.

[0024]

[0033] In addition to undergoing high-temperature processes, inspection involves the use of optoelectronic components, such as position sensors, mirrors, motors, detectors, and the like, which can dissipate large amounts of heat during inspection. Prolonged exposure of optoelectronic components to excessive heat can lead to premature failure. Such optoelectronic component failure can cause fatal errors during computer chip manufacturing or wafer defect detection. Even slight temperature changes can reduce the collection efficiency of signal electrons, such as signal charged particles (e.g., secondary electrons (SEs) and backscattered electrons (BSEs)), and thus adversely affect throughput and inspection yield. Using separate cooling feedthroughs can be undesirable because they occupy a large area of ​​the inspection system and require adjustment of the inspection system for each high-temperature process, which can lead to stage positioning errors and beam placement accuracy errors.

[0025]

[0034] Applied disturbances can affect the position of the detector relative to the signal charged particles. For example, thermal loads imposed by electronic components, the detector (particularly the detector's detecting portion), and / or incident electrons can distort the components supporting the detector. Such thermal loads can occur during detector operation. Additionally or alternatively, thermal loads can occur when a fault occurs. Furthermore, components can be exposed to very high temperatures during operation, such as during bakeout. Distortion of the components supporting the detector can change the position of the detecting portion relative to the signal charged particles. This can result in a misalignment of the detector, potentially causing the errors described above.

[0026]

[0035] At least some operations may rely on very high heat loads, e.g., bakeout. Some components, such as the detector, may be able to be exposed to extreme heat loads. However, it may be preferable to avoid exposing other components, such as the electronics, to such high heat loads.

[0027]

[0036] Devices that can be used for inspection, such as detector modules that include at least a detector, may be limited in the space in which they can be provided. Thus, there may be limitations on the volume available for the detector module, which generally means that it is preferable to limit the total footprint of the detector and any components included in the detector module. Therefore, the detector module is preferably provided in a compact configuration.

[0028]

[0037] This disclosure describes, among other things, a detector module and associated methods for detecting incident charged particle beams.

[0029]

[0038] This disclosure describes, among other things, methods and systems for sealing a vacuum system configured to provide an atmospheric environment and a vacuum chamber environment using a printed circuit board (PCB). In some embodiments, the PCB can form an interface between the vacuum chamber environment and the atmospheric environment. A device can be connected to the PCB and exposed to the vacuum chamber environment. In some embodiments, a cooling system can be connected to the PCB and exposed to the atmospheric environment. The cooling system can provide mechanical support to the PCB, enhance the hermetic seal provided by the PCB, and provide cooling for the device. In some embodiments, the device can be provided in an opening in a ring within the vacuum chamber environment. A sealing layer can be provided between the ring and the PCB such that the sealing layer is provided on one side of the PCB. The inspection system can be adapted for multiple applications that optimize the throughput of the inspection system.

[0030]

[0039] The relative dimensions of components in the drawings may be exaggerated for clarity. Within the following description of the drawings, the same or similar reference numbers refer to the same or similar components or entities, and only the differences with respect to individual embodiments are described.

[0031]

[0040] As used herein, unless otherwise stated, the term "or" includes all possible combinations unless impracticable. For example, if a component is stated to include A or B, the component may include A or B, or A and B, unless otherwise stated or impracticable. As a second example, if a component is stated to include A, B, or C, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A, B, and C, unless otherwise stated or impracticable.

[0032]

[0041] FIG. 1 illustrates an exemplary electron beam inspection (EBI) system 100 consistent with embodiments of the present disclosure. The EBI system 100 can be used for imaging. As shown in FIG. 1, the EBI system 100 includes a main chamber 101, a load / lock chamber 102, an electron beam tool 104, and an equipment front-end module (EFEM) 106. The electron beam tool 104 is disposed within the main chamber 101. The EFEM 106 includes a first loading port 106a and a second loading port 106b. The EFEM 106 may include additional loading ports. The first loading port 106a and the second loading port 106b receive wafer front-opening unified pods (FOUPs) containing wafers (e.g., semiconductor wafers or wafers made of other materials) or samples (wafers and samples may be used interchangeably) to be inspected. A "lot" is a plurality of wafers that can be loaded for processing as a batch.

[0033]

[0042] One or more robot arms (not shown) in the EFEM 106 may transfer the wafer to the load / lock chamber 102. The load / lock chamber 102 is connected to a load / lock vacuum pumping system (not shown) that removes gas molecules from the load / lock chamber 102 to reach a first pressure that is less than atmospheric pressure. After the first pressure is reached, one or more robot arms (not shown) may transfer the wafer from the load / lock chamber 102 to the main chamber 101. The main chamber 101 is connected to a main chamber vacuum pumping system (not shown) that removes gas molecules from the main chamber 101 to reach a second pressure that is less than the first pressure. After the second pressure is reached, the wafer is subjected to inspection by the electron beam tool 104. The electron beam tool 104 may be a single beam system or a multi-beam system.

[0034]

[0043] The controller 109 is electronically connected to the electron beam tool 104. The controller 109 may be a computer configured to perform various controls of the EBI system 100. Although the controller 109 is shown in FIG. 1 as being external to the structure including the main chamber 101, the load / lock chamber 102, and the EFEM 106, it is understood that the controller 109 may be part of the structure.

[0035]

[0044] In some embodiments, the controller 109 may include one or more processors (not shown). A processor may be a general-purpose or specific electronic device capable of manipulating or processing information. For example, a processor may include a central processing unit (i.e., "CPU"), a graphics processing unit (i.e., "GPU"), an optical processor, a programmable logic controller, a microcontroller, a microprocessor, a digital signal processor, an intellectual property (IP) core, a programmable logic array (PLA), a programmable array logic (PAL), a generic array logic (GAL), a multifunction programmable logic device (CPLD), a field programmable gate array (FPGA), a system-on-chip (SoC), an application-specific integrated circuit (ASIC), and any number or combination of any type of circuit capable of processing data. A processor may also be a virtual processor, including one or more processors distributed across multiple machines or devices coupled via a network.

[0036]

[0045] In some embodiments, the controller 109 may further include one or more memories (not shown). Memory may be a general-purpose or specific electronic device capable of storing code and data accessible by a processor (e.g., via a bus). For example, memory may include any number or combination of random access memory (RAM), read-only memory (ROM), optical disks, magnetic disks, hard drives, solid-state drives, flash drives, security digital (SD) cards, memory sticks, compact flash (CF) cards, or any type of storage device. Code may include an operating system (OS) and one or more application programs (i.e., "apps") for specific tasks. Memory may also be virtual memory, including one or more memories distributed across multiple machines or devices coupled via a network.

[0037]

[0046] Reference is now made to FIG. 2, which is a schematic diagram of an exemplary electron beam tool 104 of the EBI system 100 of FIG. 1. The electron beam tool 104 is described herein as a multi-beam electron optical column 104, but as noted above, it can also be used as a single-beam electron optical column. Furthermore, the EBI system is referred to as the inspection apparatus 100 of FIG. 1. In an alternative embodiment, the inspection apparatus 100 is a single-beam inspection apparatus. The electron optical column 104 can include an electron source 201, a beam former array 271 (also known as a Coulomb aperture plate, "gun aperture plate," Coulomb aperture array, or pre-sub-beam forming aperture array), a condenser lens 210, a source converter (also known as a source converter unit or micro-optic array) 220, an objective lens 231, and a target 208 (which can be a sample). In one embodiment, the condenser lens 210 is magnetic. The target 208 can be supported by a support on a stage. The stage can be motorized. The stage moves so that the target 208 is scanned by the incident electrons. The electron source 201, the beamformer array 271, and the condenser lens 210 may be components of an illumination system included by the electron-optical column 104. The source converter 220 (also known as a source conversion unit), which is described in more detail below, and the objective lens 231 may also be components of a projection system included by the electron-optical column 104.

[0038]

[0047] The electron source 201, beam former array 271, condenser lens 210, source converter 220, and objective lens 231 are aligned with a primary electron optical axis 204 (also known as a primary optical axis) of the electron optical column 104. The electron source 201 may generate a primary beam 202 (also known as a primary electron beam) generally along the electron optical axis 204 and with a source crossover (virtual or real) 203 (also known as a primary beam crossover). In 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 202.

[0039]

[0048] The beam former array 271 cuts off peripheral electrons in the primary electron beam 202 to reduce the resulting Coulomb effect. The primary electron beam 202 can be trimmed by the beam former array 271 into a specified number of sub-beams, such as three sub-beams 211, 212, and 213. It should be understood that this description is intended to apply to an electron optical column 104 having any number of sub-beams, such as one, two, or four or more. In operation, the beam former array 271 is configured to block peripheral electrons to reduce the Coulomb effect, which can increase the size of each of the probe spots 291, 292, and 293 and, as a result, degrade inspection resolution. The beam former array 271 reduces aberrations due to Coulomb interactions between electrons projected onto the beam. The beam former array 271 can include multiple apertures to generate primary sub-beams even before the source converter 220.

[0040]

[0049] The source converter 220 is configured to convert the beam (including sub-beams, if any) transmitted by the beamformer array 271 into sub-beams that are projected towards the target 208. The terms source converter / source converter unit can be used interchangeably and simply as a general term for the group of components that form beamlets from the sub-beams.

[0041]

[0050] As shown in FIG. 2 , in one embodiment, electron optical column 104 includes a beam-limiting aperture array 221 having an aperture pattern (i.e., apertures arranged in an array) configured to define the outer dimensions of the beamlets (or sub-beams) projected toward target 208. In one embodiment, beam-limiting aperture array 221 is part of source converter 220. In an alternative embodiment, beam-limiting aperture array 221 is part of the main column's system up beam. In one embodiment, beam-limiting aperture array 221 splits one or more of sub-beams 211, 212, 213 into beamlets such that the number of beamlets projected toward target 208 is greater than the number of sub-beams transmitted through beam former array 271. In an alternative embodiment, beam-limiting aperture array 221 maintains the number of sub-beams incident on beam-limiting aperture array 221, in which case the number of sub-beams may be equal to the number of beamlets projected toward target 208.

[0042]

[0051] 2 , in one embodiment, the electron optical column 104 includes a pre-bend deflector array 223 having pre-bend deflectors 223_1, 223_2, and 223_3 for bending the sub-beams 211, 212, and 213, respectively. The pre-bend deflectors 223_1, 223_2, and 223_3 may bend the paths of the sub-beams 211, 212, and 213 and send them to the beam-limiting aperture array 221.

[0043]

[0052] The electron optical column 104 may also include an image-forming element array 222 having image-forming deflectors 222_1, 222_2, and 222_3. There is a respective deflector 222_1, 222_2, and 222_3 associated with the path of each beamlet. The deflectors 222_1, 222_2, and 222_3 are configured to deflect the path of the beamlets toward the electron optical axis 204. The deflected beamlets form virtual images (not shown) of the source crossover 203. In the current embodiment, these virtual images are projected by the objective lens 231 onto the target 208, forming probe spots 291, 292, and 293 thereon. The electron optical column 104 may also include an aberration compensator array 224 configured to compensate for aberrations that may be present in each of the sub-beams. In one embodiment, the aberration compensator array 224 includes a lens configured to operate on each beamlet. The lens may take the form of an array of lenses. Lenses in the array can operate on different beamlets of the multi-beam. The aberration compensator array 224 can include, for example, a field curvature compensator array (not shown) with, for example, microlenses. The field curvature compensators and microlenses can be configured to compensate individual sub-beams for field curvature aberrations apparent at, for example, the probe spots 291, 292, and 293. The aberration compensator array 224 can include an astigmatism compensator array (not shown) with microastigmatism compensators. The microastigmatism compensators can be controlled to operate on the sub-beams, for example, to compensate for astigmatism that would otherwise be present at the probe spots 291, 292, and 293.

[0044]

[0053] The source converter 220 may further include a pre-bending deflector array 223 having pre-bending deflectors 223_1, 223_2, and 223_3 for bending the sub-beams 211, 212, and 213, respectively. The pre-bending deflectors 223_1, 223_2, and 223_3 may bend the paths of the sub-beams to send them to the beam-limiting aperture array 221. In one embodiment, the pre-bending micro-deflector array 223 may be configured to bend the sub-beam paths of the sub-beams toward an orthogonal direction of the plane on the beam-limiting aperture array 221. In an alternative embodiment, the condenser lens 210 may adjust the path directions of the sub-beams onto the beam-limiting aperture array 221. Condenser lens 210 may, for example, focus (collimate) the three sub-beams 211, 212, and 213 into substantially parallel beams along primary electron optical axis 204, such that the three sub-beams 211, 212, and 213 are substantially normally incident on source converter 220, which may correspond to beam-limiting aperture array 221. In such an alternative embodiment, pre-bending deflector array 223 may not be necessary.

[0045]

[0054] The image forming element array 222, the aberration compensator array 224 and the pre-bending deflector array 223 may constitute multiple layers of sub-beam steering devices, some of which may be in the form of arrays, for example, micro-deflectors, micro-lenses or micro-astigmatism compensators. The beam path may be rotationally steered. The rotational correction may be applied by magnetic lenses. Additionally or alternatively, the rotational correction may be achieved by existing magnetic lenses, such as a condenser lens arrangement.

[0046]

[0055] In the present example of electron optical column 104, the beamlets are deflected towards the electron optical axis 204 by deflectors 222_1, 222_2 and 222_3, respectively, of the array of image forming elements 222. It should be understood that the beamlet paths may already correspond to the electron optical axis 204 before reaching the deflectors 222_1, 222_2 and 222_3.

[0047]

[0056] The objective lens 231 focuses the beamlets onto the surface of the target 208, i.e., projects three virtual images onto the target surface. The three images formed by the three sub-beams 211-213 on the target surface form three probe spots 291, 292, and 293 thereon. In one embodiment, the deflection angles of the sub-beams 211-213 are adjusted to pass through or approach the front focal point of the objective lens 231, reducing or limiting off-axis aberrations of the three probe spots 291-293. In some arrangements, the objective lens 231 is magnetic. Although three beamlets are mentioned, this is by way of example only. Any number of beamlets may be present.

[0048]

[0057] The manipulators are configured to manipulate one or more charged particle beams. The term manipulator encompasses deflectors, lenses, and apertures. The pre-bending deflector array 223, the aberration compensator array 224, and the image forming element array 222, individually or in combination with each other, may be referred to as manipulator arrays because they manipulate one or more sub-beams or beamlets of charged particles. The lenses and deflectors 222_1, 222_2, and 222_3 may be referred to as manipulators because they manipulate one or more sub-beams or beamlets of charged particles.

[0049]

[0058] In one embodiment, a beam separator may be provided. Although not shown in FIG. 2, FIG. 3 depicts a beam separator 233. The beam separator may be located down-beam of the source converter 220. The beam separator may be, for example, a Wien filter including an electrostatic dipole field and a magnetic dipole field. The beam separator may be positioned between adjacent sections of a shield in the direction of the beam path. The inner surface of the shield may be radially inside the beam separator. Alternatively, the beam separator may reside within the shield. In operation, the beam separator may be configured to exert an electrostatic force on individual electrons of the sub-beam due to the electrostatic dipole field. In one embodiment, the electrostatic force is equal in magnitude but opposite in direction to the magnetic force exerted on individual primary electrons of the sub-beam by the magnetic dipole field of the beam separator. Thus, the sub-beam may pass through the beam separator in at least a substantially straight line with at least substantially zero deflection angle. The direction of the magnetic force depends on the direction of electron motion, while the direction of the electrostatic force does not. Therefore, because the secondary and backscattered electrons generally travel in the opposite direction compared to the primary electrons, the magnetic force on the secondary and backscattered electrons no longer cancels the electrostatic force, and as a result, the secondary and backscattered electrons traveling through the beam separator are deflected away from the electron optical axis 204.

[0050]

[0059] In one embodiment, a secondary column is provided that includes a detector element for detecting a corresponding secondary charged particle beam. The secondary column is not shown in FIG. 2. The secondary column is described in further detail in connection with FIG. 3. When the secondary beam is incident on a detector element, the detector element may generate a corresponding intensity signal output. The output may be directed to an image processing system (e.g., controller 109). Each detector element may include one or more pixels. The intensity signal output of the detector element may be the sum of signals generated by all pixels in the detector element.

[0051]

[0060] In one embodiment, a secondary projection apparatus and its associated electron detection device (not shown) are provided. The secondary projection apparatus and its associated electron detection device may be aligned with the secondary electron optical axis of the secondary column. In one embodiment, a beam separator is positioned to deflect the path of the secondary electron beam toward the secondary projection apparatus. The secondary projection apparatus then focuses the path of the secondary electron beam onto multiple detection areas of the electron detection device. The secondary projection apparatus and its associated electron detection device may record and generate an image of the target 208 using the secondary electrons or backscattered electrons.

[0052]

[0061] In one embodiment, the inspection device 100 includes a single source.

[0053]

[0062] Any element or group of elements may be replaceable or field replaceable within the electron-optical column. One or more electron-optical components within the column, particularly those that operate on or generate sub-beams, such as the aperture array and manipulator array, may include one or more microelectromechanical systems (MEMS). The pre-bending deflector array 223 may be a MEMS. MEMS are miniaturized mechanical and electromechanical elements fabricated using microfabrication techniques. In one embodiment, the electron-optical column 104 includes apertures, lenses, and deflectors formed as MEMS. In one embodiment, the lenses and manipulators, such as the deflectors 222_1, 222_2, and 222_3, are controllable passively, actively, as an entire array, individually, or in groups within the array to control the beamlets of charged particles projected toward the target 208.

[0054]

[0063] In one embodiment, the electron optical column 104 may include alternative and / or additional components along the charged particle path, such as lenses and other components, some of which are described above with reference to FIG. 1 and / or below with reference to FIG. 3. In particular, an embodiment includes an electron optical column 104 that splits a charged particle beam from a source into multiple sub-beams. Multiple respective objective lenses may project the sub-beams onto a sample. In some embodiments, multiple condenser lenses are provided from the objective lens to the up-beam. The condenser lenses focus each of the sub-beams to an intermediate focus at the up-beam of the objective lens. In some embodiments, a collimator is provided from the objective lens to the up-beam. To reduce focus errors and / or aberrations, a corrector may be provided. In some embodiments, such a corrector is integrated into the objective lens or positioned directly adjacent to the objective lens. If a condenser lens is provided, such a corrector may additionally or alternatively be integrated into or positioned directly adjacent to the condenser lens and / or positioned at or directly adjacent to the intermediate focus. A detector is provided for detecting charged particles emitted by the sample. The detector may be integrated with the objective lens. The detector may be provided on the bottom surface of the objective lens so as to face the sample in use. The condenser lens, objective lens and / or detector may be formed as MEMS or CMOS devices.

[0055]

[0064] Reference is now made to FIG. 3 , which is a schematic diagram illustrating an exemplary electron beam tool 104, including a multi-beam inspection tool, that is part of the EBI system 100 of FIG. 1 , consistent with an embodiment of the present disclosure. The tool 104 of FIG. 3 may function or include features as described in connection with the tool 104 of FIG. 2 . In some embodiments, the electron beam tool 104 may be operated as a single-beam inspection tool that is part of the EBI system 100 of FIG. 1 . The multi-beam electron beam tool 104 (also referred to herein as apparatus 104) includes an electron source 201, a Coulomb aperture plate (or “gun aperture plate”) 271, a condenser lens 210, a source conversion unit 220, a primary projection system 230, a motorized stage 209, and a sample holder 207 that is supported by the motorized stage 209 and holds a sample 208 (e.g., a wafer or photomask) to be inspected. The multi-beam electron beam tool 104 may further include a secondary projection system 250 and an electron detection device 240. The primary projection system 230 may include an objective lens 231. The electronic detection device 240 may include a plurality of detection elements 241, 242, 243. A beam separator 233 and a deflection scanning unit 232 may be positioned inside the primary projection system 230.

[0056]

[0065] The electron source 201, the Coulomb aperture plate 271, the condenser lens 210, the source conversion unit 220, the beam separator 233, the deflection scanning unit 232 and the primary projection system 230 may be aligned with a primary optical axis 204 of the apparatus 104. The secondary projection system 250 and the electron detection device 240 may be aligned with a secondary optical axis 251 of the apparatus 104.

[0057]

[0066] The electron source 201 may include a cathode (not shown) and an extractor or anode (not shown), and in operation, the electron source 201 is configured to emit primary electrons from the cathode, which are extracted or accelerated by the extractor and / or anode to form a primary electron beam 202 that forms a primary beam crossover (virtual or real) 203. The primary electron beam 202 may be visualized as emitting from the primary beam crossover 203.

[0058]

[0067] The source conversion unit 220 may function or include features as described in connection with FIG. 2 . The source conversion unit 220 may include an image-forming element array (not shown), an aberration compensator array (not shown), a beam-limiting aperture array (not shown), and a pre-bending micro-deflector array (not shown). In some embodiments, the pre-bending micro-deflector array deflects multiple primary beamlets 211, 212, 213 of the primary electron beam 202 to be normally incident on the beam-limiting aperture array, the image-forming element array, and the aberration corrector array. In some embodiments, the apparatus 104 can be operated as a single-beam system such that a single primary beamlet is generated. In some embodiments, the condenser lens 210 is designed to focus the primary electron beam 202 into a parallel beam that is normally incident on the source conversion unit 220. The image-forming element array may include multiple micro-deflectors or micro-lenses for influencing multiple primary beamlets 211, 212, 213 of the primary electron beam 202 and forming multiple parallel images (virtual or real) of the primary beam crossover 203, one for each of the primary beamlets 211, 212, 213. In some embodiments, the aberration compensator array may include a field curvature compensator array (not shown) and an astigmatism compensator array (not shown). The field curvature compensator array may include multiple micro-lenses for compensating for field curvature aberration of the primary beamlets 211, 212, and 213. The astigmatism compensator array may include multiple micro-astigmatism compensators for compensating for astigmatism of the primary beamlets 211, 212, and 213. The beam-limiting aperture array may be configured to limit the diameter of each of the primary beamlets 211, 212, and 213. 2 shows three primary beamlets 211, 212 and 213 as an example, it being understood that the source transformation unit 220 can be configured to form any number of primary beamlets. The controller 109 can be connected to various parts of the EBI system 100 of FIG. 1, such as the source transformation unit 220, the electron detection device 240, the primary projection system 230 or the motorized stage 209.In some embodiments, the controller 109 may perform various image and signal processing functions, as described in more detail below. The controller 109 may also generate various control signals to govern the operation of the charged particle beam inspection system.

[0059]

[0068] The condenser lens 210 is configured to focus the primary electron beam 202. The condenser lens 210 may be further configured to adjust the current of the primary beamlets 211, 212, and 213 downstream of the source conversion unit 220 by changing the focusing power of the condenser lens 210. Alternatively, the current may be changed by changing the radial size of a beam-limiting aperture in a beam-limiting aperture array corresponding to each primary beamlet. The current may be changed by changing both the radial size of the beam-limiting aperture and the focusing power of the condenser lens 210. The condenser lens 210 may be an adjustable condenser lens configured such that the position of its first principal plane is movable. The adjustable condenser lens may be configured to be magnetic, such that the off-axis beamlets 212 and 213 illuminate the source conversion unit 220 with a rotation angle. The rotation angle varies depending on the focusing power or the position of the first principal plane of the adjustable condenser lens. Condenser lens 210 may be an anti-rotation condenser lens that may be configured to keep its rotation angle constant while changing the focusing power of condenser lens 210. In some embodiments, condenser lens 210 may be an adjustable anti-rotation condenser lens whose rotation angle does not change when its focusing power and the position of its first principal plane are changed.

[0060]

[0069] The objective lens 231 may be configured to focus the beamlets 211, 212, and 213 onto the sample 208 for inspection, which in the current embodiment may form three probe spots 291, 292, and 293 on the surface of the sample 208. The Coulomb aperture plate 271 is configured, in operation, to block peripheral electrons of the primary electron beam 202 to reduce the Coulomb effect, which can increase the size of each probe spot 291, 292, and 293 of the primary beamlets 211, 212, and 213, degrading inspection resolution.

[0061]

[0070] The beam separator 233 may be, for example, a Wien filter including electrostatic deflectors that generate electrostatic and magnetic dipole fields (not shown in FIG. 3 ). In operation, the beam separator 233 may be configured to exert an electrostatic force due to the electrostatic dipole field on individual electrons of the primary beamlets 211, 212, and 213. The electrostatic force is equal in magnitude but opposite in direction to the magnetic force exerted on the individual electrons by the magnetic dipole field of the beam separator 233. The primary beamlets 211, 212, and 213 may therefore pass through the beam separator 233 in at least substantially straight lines with at least substantially zero deflection angle.

[0062]

[0071] The deflection scanning unit 232 is configured, during operation, to deflect the primary beamlets 211, 212, and 213 to scan the probe spots 291, 292, and 293 over respective scan areas on a section of the surface of the sample 208. In response to the primary beamlets 211, 212, and 213 or the probe spots 291, 292, and 293 impinging on the sample 208, electrons emerge from the sample 208 to generate three secondary electron beams 261, 262, and 263. Each of the secondary electron beams 261, 262, and 263 typically includes secondary electrons (having an electron energy ≦50 eV) and backscattered electrons (having an electron energy between 50 eV and the landing energy of the primary beamlets 211, 212, and 213). The beam separator 233 is configured to deflect the secondary electron beams 261, 262, and 263 towards the secondary projection system 250. The secondary projection system 250 then focuses the secondary electron beams 261, 262, and 263 onto detector elements 241, 242, and 243 of the electron detection device 240. The detector elements 241, 242, and 243 are arranged to detect corresponding secondary electron beams 261, 262, and 263 and generate corresponding signals that are sent to the controller 109 or a signal processing system (not shown), for example, to construct an image of a corresponding scanned area of ​​the sample 208.

[0063]

[0072] In some embodiments, detector elements 241, 242, and 243 detect corresponding secondary electron beams 261, 262, and 263, respectively, and generate corresponding intensity signal outputs (not shown) to an image processing system (e.g., controller 109). In some embodiments, each detector element 241, 242, and 243 may include one or more pixels. The intensity signal output of a detector element may be the sum of signals generated by all of the pixels in the detector element.

[0064]

[0073] In some embodiments, the controller 109 may include an image processing system including an image acquirer (not shown) and a storage device (not shown). The image acquirer may include one or more processors. For example, the image acquirer may include a computer, a server, a mainframe host, a terminal, a personal computer, any type of mobile computing device, etc., or a combination thereof. The image acquirer may be communicatively coupled to the electronic detection device 240 of the apparatus 104 through, among other means, electrical conductors, fiber optic cables, portable storage media, IR, Bluetooth, the Internet, a wireless network, a radio, or a combination thereof. In some embodiments, the image acquirer may receive signals from the electronic detection device 240 and construct an image. In this manner, the image acquirer may acquire an image of the sample 208. The image acquirer may perform various post-processing functions, such as generating contours, superimposing indicators on the acquired image, etc. The image acquirer may be configured to perform adjustments, such as brightness and contrast, of the acquired image. In some embodiments, the storage device may be a storage medium such as a hard disk, a flash drive, cloud storage, random access memory (RAM), other types of computer-readable memory, etc. A storage device may be coupled to the image acquirer and may be used to store raw image data scanned as original images and post-processed images.

[0065]

[0074] In some embodiments, the image acquirer may acquire one or more images of the sample based on an imaging signal received from the electron detection device 240. The imaging signal may correspond to a scanning motion to perform charged particle imaging. The acquired image may be a single image including multiple imaging regions. The single image may be stored in a storage device. The single image may be an original image divided into multiple regions. Each region may include one imaging region that includes a feature of the sample 208. The acquired image may include multiple images of a single imaging region of the sample 208 sampled multiple times over a time sequence. The multiple images may be stored in a storage device. In some embodiments, the controller 109 may be configured to perform image processing steps using multiple images of the same location of the sample 208.

[0066]

[0075] In some embodiments, the controller 109 may include measurement circuitry (e.g., an analog-to-digital converter) to obtain a distribution of detected secondary electrons. The electron distribution data collected during the detection time window, in combination with the corresponding scan path data of each of the primary beamlets 211, 212, and 213 incident on the wafer surface, may be used to reconstruct an image of the wafer structure under inspection. The reconstructed image may be used to reveal various features of the internal or external structure of the sample 208, thereby revealing any defects that may be present in the wafer.

[0067]

[0076] In some embodiments, the controller 109 may control the motorized stage 209 to move the sample 208 during inspection of the sample 208. In some embodiments, the controller 109 may enable the motorized stage 209 to move the sample 208 in a direction continuously at a constant velocity. In other embodiments, the controller 109 may enable the motorized stage 209 to vary the speed of movement of the sample 208 over time depending on the step in the scanning process.

[0068]

[0077] 3 shows that apparatus 104 uses three primary electron beams, it is understood that apparatus 104 may use two or more primary electron beams. Alternatively, apparatus 104 may use only a single beam. This disclosure does not limit the number of primary electron beams used in apparatus 104. In some embodiments, apparatus 104 may be an SEM used for lithography.

[0069]

[0078] Compared to a single charged particle beam imaging system (“single beam system”), a multiple charged particle beam imaging system (“multi-beam system”) can be designed to optimize throughput for different scanning modes. By using beam arrays with different geometries, embodiments of the present disclosure accommodate different throughput and resolution requirements, providing multi-beam systems with the ability to optimize throughput for different scanning modes.

[0070]

[0079] A non-transitory computer-readable medium may be provided that stores instructions for a processor (e.g., the processor of controller 109 of FIGS. 1-2) to perform image processing, data processing, beamlet scanning, database management, graphic display, operation of a charged particle beam instrument or another imaging device, etc. Common forms of non-transitory medium include, for example, floppy disks, flexible disks, hard disks, solid state drives, magnetic tape or any other magnetic data storage medium, CD-ROMs, any other optical data storage medium, any physical medium with a pattern of holes, RAM, PROMs and EPROMs, FLASH-EPROMs or any other flash memory, NVRAM, cache, registers, any other memory chip or cartridge, and networked versions thereof.

[0071]

[0080] As discussed above, charged particles can be reflected or emitted from a person or object that can be used to obtain information about a structure (e.g., target 208). A charged particle beam, which may alternatively be referred to as a signal beam (i.e., signal charged particle beam) and / or an incident charged particle beam, is generated when the primary beam is incident on target 208, which generates signal particles, e.g., backscattered electrons and secondary electrons, as discussed above. It would be beneficial to provide a detector that can be used to detect the incident charged particle beam in order to obtain information about target 208.

[0072]

[0081] The incidental charged particle beam may alternatively be referred to as a secondary beam. The incidental charged particle beam may include secondary electrons and / or backscattered electrons. The axis of the incidental charged particle beam may be the same as the incidental charged particle beam path. The path of the incidental charged particle beam may be interchangeable with the axis of the incidental charged particle beam.

[0073]

[0082] During the detection of charged particles, deformations of the components supporting the detector can occur, causing the detector to move and leading to inaccurate measurements. This can be a greater problem in certain tools, such as multi-beam tools, where the detector is larger to allow for the detection of multiple beams.

[0074]

[0083] In the present invention, a detector module is provided that includes a detector and a support. Reference is now made to FIG. 4A, which is a schematic diagram illustrating an exemplary detector module 500 and an exemplary support 501. The detector module 500 may be part of the multi-beam system of FIG. 2 and / or FIG. 3. More specifically, the detector module 500 may provide the electronic detection device 240 shown in FIG. 3. As depicted, the detector module 500 is characterized by a support 501.

[0075]

[0084] The detector module 500 is suitable for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool. The charged particle beam evaluation tool may be at least a part of the tool 104 (or apparatus 104). The detector module 500 may be made of multiple components usable as part of the wall of the vacuum chamber. The detector module 500 may at least partially define an end of the vacuum chamber. In other words, the detector module 500 may form the end of the vacuum chamber, more specifically, the end wall of the vacuum chamber. This is true when the detector module 500 is in use and / or in place as part of the tool 104. The detector module 500 may seal the vacuum chamber by providing a sealing cover over an aperture in the vacuum chamber. The detector module 500 may form the end of a secondary column. Preferably, a source (such as source 201) is at another end, for example, a primary column (which may correspond to the electron optical column in FIG. 2). The vacuum chamber may be in fluid communication with other chambers, for example, the primary column and / or a stage chamber. In use, these chambers may all be part of the same vacuum chamber / vacuum chamber environment 530 .

[0076]

[0085] The detector 531 is configured to operate within a vacuum chamber, i.e., a vacuum chamber environment 530. It will be understood that a vacuum chamber is a chamber that can provide the vacuum chamber environment 530 at some point during operation of the detector module 500. Components external to the detector module 500, such as components that are part of the tool 104, may be used to provide the vacuum within the vacuum chamber.

[0077]

[0086] The operation of the detector module 500 includes detector operation for detecting signal charged particles (i.e., secondary beams) to fulfill the primary purpose of the detector module 500. The operation of the detector module 500 also includes other operations (i.e., not involving operation of the detector 531 for detecting signal charged particles), such as maintenance operations, e.g., bakeout, during which a vacuum may be created.

[0078]

[0087] The detector 531 is generally positioned relative to the incidental charged particle beam. The detector 531 is configured to be alignable with the incidental charged particle beam path 535. That is, the detector 531 of the detector module 500 can be positioned to align with the incidental charged particle beam path 535. For example, when the detector module 500 is used as the end of a secondary column, the incidental charged particle beam is incident on the detector 531 during use. As described above, the incidental charged particle beam may include secondary electrons and / or backscattered electrons. The incidental charged particle beam path 535 may be the main path along which the incidental charged particles (e.g., secondary electrons and / or backscattered electrons) travel after being ejected from the target 208. The incidental charged particle beam path 535 may be substantially centered relative to the detector 531 (specifically, relative to the detection portion of the detector 531).

[0079]

[0088] The support 501 is suitable for defining at least a portion of a wall of a vacuum chamber. For example, the support 501 may define at least a portion of a wall when the detector module 500 is in use and / or in place in a portion of the tool 104. The support 501 may be configured to cover an aperture in the vacuum chamber. The support 501 may be used to seal the vacuum chamber, and in particular to seal an aperture in the vacuum chamber. Thus, the support 501 may be a portion of the detector module 500 that is used to define a wall / edge of the vacuum chamber.

[0080]

[0089] The support 501 may include a feedthrough 522. The feedthrough 522 may be planar. In other words, the feedthrough 522 may be planar or flat. The feedthrough 522 may be rigid. The feedthrough 522 may be any suitable material. The feedthrough 522 may be a printed circuit board (PCB). The feedthrough 522 may be used to cover an aperture of a vacuum chamber. The feedthrough 522 may be larger than the aperture of the vacuum chamber. The feedthrough 522 may be a means for providing power and / or electrical connection through the feedthrough 522. The feedthrough 522 may be a printed circuit board (PCB). Providing the feedthrough 522 as a PCB may be beneficial, for example, to facilitate electrical connection through the board from one side to another using integrated electrical connections provided in the structure of the PCB.

[0081]

[0090] The detector 531 may be attached to the feedthrough 522. The detector 531 may be attached in any suitable manner, for example, using adhesives and / or welding and / or soldering. The detector 531 may be electrically connected through the feedthrough 522. That is, an electrical connection may be provided through the feedthrough 522 to which the detector 531 is connected, i.e., attached. The electrical connection through the feedthrough 522 may be provided such that the electrical connection connects to the detector 531 on one side of the feedthrough 522 and the electrical connection extends through the feedthrough 522 to the other side of the feedthrough 522.

[0082]

[0091] The support 501 may include a body that may be configured to support the feedthrough 522. The body of the support 501 may be provided as a single, integral body. Preferably, the body of the support 501 is provided as separate parts that are connected together. For example, the support 501 may include a ring 521 configured to support the feedthrough 522. The ring 521 may contact the feedthrough 522. The ring 521 may contact the feedthrough 522 through a connecting portion or layer, for example, through a solder layer and / or an adhesive layer. The feedthrough 522 may cover an aperture in the ring 521. The support 501 may include other portions, such as an outer mounting portion 519 and an inner mounting portion 520. The inner mounting portion 520 may be radially inward of the outer mounting portion 519. The support 501 may be attached to another portion of the secondary column, such as another component of the detector module 500 (e.g., via the outer mounting portion 519) and / or to another portion of the secondary column, such as a chamber wall of the secondary column, via the inner mounting portion 520 and / or the outer mounting portion 519. The inner mounting portion 520 and / or the outer mounting portion 519 may each be configured to be attached to two or more other components of the secondary column.

[0083]

[0092] The support 501 may be deformed by an applied disturbance. This typically occurs during operation of the detector module 500. More specifically, there are certain operations of the detector module 500 that may cause the support 501 to be deformed by a disturbance. For example, as described above, bakeout is a high-temperature process during operation of the detector module 500 that may be used to prepare the detector module 500 for use. Furthermore, during operation of the detector 531 for detection of charged particles, some thermal fluctuations may occur that result in an applied disturbance that deforms the support. The deformation of the support may be temporary and time-dependent.

[0084]

[0093] The applied disturbance may apply forces to the support 501 in a variety of different ways, directions, and planes, resulting in deformation of the support 501 in a variety of ways. Because the detector 531 is attached to a portion of the support 501, deformation of the support 501 will generally change the position of the detector 531 relative to the incidental charged particle beam path 535. As such, the applied disturbance and the resulting deformation of the support 501 may affect the position of the detector 531 relative to the incidental charged particle beam path 535. This may affect the position of the detector 531 in a variety of different ways, for example, in the plane of the detector 531 or along the incidental charged particle beam path 535. The applied disturbance may result in a rotation of the detector 531 about the incidental charged particle beam path 535 and / or a tilt (i.e., angle) of the detector 531 from the ideal detector plane (i.e., orthogonal to the incidental charged particle beam path 535 or the initial calibration position of the incidental charged particle beam path 535).

[0085]

[0094] The detector module 500 is configured such that the operational position of the detector 531 is maintained relative to the incidental charged particle beam path 535. Thus, the detector module 500 is configured to maintain the detector 531 in the same position relative to the incidental charged particle beam path 535, taking into account disturbances applied to the support 501 and / or the detector 531 as described above. The detector module 500 may include active and / or passive arrangements for maintaining the detector 531 in a predetermined position. As described in more detail below, various alternative embodiments are provided with different arrangements for maintaining the detector 531 in a predetermined position, which may be provided separately or in combination.

[0086]

[0095] In general, the detector module 500 may be operated around the incident charged particle beam such that distortion / deformation of the support 501, and in particular the feedthrough 522, is symmetric. This may be achieved in many different ways, for example, by providing a resilient member, symmetric positioning of components, and / or by using a thermal conditioning system. The detector module 500 may be configured such that deformation of the support due to thermal fluctuations during operation of the detector module 500 is symmetric.

[0087]

[0096] Additionally, deformation of the support 501, such as via an elastic member as described below, may reduce mechanical stress on the detector 531, for example, when the detector module 501 is at a high temperature. In other words, the detector module 500 of the present invention may be advantageously robust against deformation, for example, due to bakeout.

[0088]

[0097] The detector module 500 may partially constitute a wall of a vacuum chamber. This means that when the detector module 500 is positioned as part of a vacuum chamber, it can form at least a part of the vacuum chamber wall. In other words, the detector module 500 can be used as part of a vacuum chamber, and is therefore suitable for providing a vacuum environment 530 within the vacuum chamber. When the detector module 500 is positioned as part of the vacuum chamber, the detector 531 is positioned within the vacuum chamber.

[0089]

[0098] The feedthrough 522 may include a first side 522A and a second side 522B. The second side 522B is opposite the first side 522A. The first side 522A may be adapted to be exposed to an atmospheric environment 510. The first side 522A may be exposed to the atmospheric environment 510 during operation of the detection module 500. The second side 522B may be adapted to be exposed to a vacuum chamber. The second side 522B may be exposed to a vacuum chamber environment 530 during operation of the detection module 500. Thus, the first side 522A may be referred to as the atmospheric side, and / or the second side 522B may be referred to as the vacuum side.

[0090]

[0099] The second side 522B can be used to cover an aperture in the vacuum chamber, for example, an aperture in the wall of the vacuum chamber or an end opening of the vacuum chamber. This means that the feedthrough 522 can be positioned across the aperture (i.e., opening) of the vacuum chamber so that the second side 522B faces the vacuum chamber environment 530. The detector 531 can be positioned on the portion of the second side 522B of the feedthrough 522 that covers the aperture. That is, the detector 531 can be positioned on the feedthrough 522 facing the vacuum chamber. Thus, the detector 531 can be positioned within the vacuum chamber environment 530 and at the opening in the wall of the vacuum chamber. The detector 531 can be attached to the second side 522B in any suitable manner, for example, using an adhesive and / or welding and / or soldering.

[0091]

[0100] The detector module 500 may include elastic members 514. As described below, the elastic members 514 may be provided in different regions, and examples of a first type of elastic member 514A and a second type of elastic member 514B are described below. Reference to elastic members 514 may apply to the first type of elastic member 514A, the second type of elastic member 514B, or both.

[0092]

[0101] The elastic member 514 may be a passive component used to maintain the position of the detector 531 relative to the incidental charged particle beam path 535. In other words, the elastic member 514 may be used to maintain the position of the detector 531 without additional control provided to the elastic member 514. The elastic member 514 may be beneficial in helping to reduce or avoid misalignment of the detector 531. The elastic member 514 may support the detector 531 so that the detector 531 can “breathe” and maintain alignment with the incidental charged particle beam path 535, even though distortions may occur due to applied disturbances such as thermal loads. This means that alignment and adjustment made at a certain temperature during an operation, such as a detection operation, may also be maintained during certain operations, such as maintenance operations, in which disturbances such as pressure and / or heat are applied to the detector module. Then, when such temperature disturbances are removed, such as when returning from a maintenance operation to a detection operation, the detector maintains its position, and if the detector's position shifted between the detection operation and the maintenance operation, such shift is reversed, changing the state of the detector module for the detection operation. The elastic member 514 may be configured to distribute an applied disturbance evenly over the elastic member 514 .

[0093]

[0102] The elastic member 514 may be provided in a variety of different forms. For example, the elastic member 514 may be a flexible element and / or a leaf spring. The elastic member 514 may be connected to any suitable portion of the support 501 that allows deformation of the support 501 to be counteracted by fluctuations in the movement of the elastic member 514. The elastic member 514 may deform substantially around the incidental charged particle beam path 535, for example under thermal load, so as to maintain the position of the detector 531 attached to the feedthrough 522 relative to the incidental charged particle beam path 535.

[0094]

[0103] The resilient member 514 may be used to support the feedthrough 522. The resilient member 514 may surround the feedthrough 522. In other words, the resilient member 514 may be positioned radially outward of the feedthrough 522. The resilient member 514 may be annular, for example, a ring. The resilient member 514 may connect the feedthrough 522 to other parts of the support 501 or to components external to the detector module 500. The resilient member 514 may be provided within or on the support 501, as described further below.

[0095]

[0104] The resilient member 514 may be configured such that, during operation of the detector 531, deformation of the support due to a disturbance is symmetrical with respect to the incident charged particle beam path 535. The resilient member 514 may be configured in this manner due to movement of the resilient member 514 in response to deformation of the support 501. This is beneficial in that the resilient member 514 may reduce or prevent mechanical stress on the feedthrough 522 and / or the detector 531 that might otherwise occur due to deformation of the support 501.

[0096]

[0105] The elastic member 514 may be configured to move in a single direction. In other words, the elastic member 514 may be compliant in one direction. As described in connection with the first type of elastic member 514A, the elastic member 514A may be compliant in the radial direction. Preferably, the detector 531 is designed with an assumed thermal center that coincides with the charged particle beam path 535, and the elastic member 514 is designed to be compliant radially inward and outward relative to the thermal center. As described in connection with the second type of elastic member 514B, the elastic member 514B may be compliant in the direction of the incident charged particle beam path 535.

[0097]

[0106] Movement of the resilient member 514 in at least one direction can be limited, for example, by a mechanical feature. For example, movement of the resilient member 514 can be limited in a circumferential direction. The resilient member 514 can include a mechanical feature to prevent misalignment of the detector 531. For example, the resilient member 514 can include an alignment pin, also referred to as a protrusion, that can provide such a mechanical feature. An exemplary alignment pin 516 is shown in FIG. 4B, which is an exemplary cross-section through the resilient member 514, e.g., the resilient member 514A of FIG. 4A. As shown, the support 501 includes a recess 517 configured to mate with the protrusion 516, preventing relative rotation between the support 501 and the resilient member 514 about the incident charged particle beam path 535. Thus, the mating components of the support 501 and the resilient member 514 can prevent movement of the resilient member 514 in a particular direction, such as the circumferential direction. This can be beneficial in addressing rotational distortion. The recess 517 is shown as being radially inward of the resilient member, and the alignment pin 516 is on the radially inner surface of the resilient member 514. However, the alignment pin 516 can be on the radially outer surface of the resilient member 514, and the corresponding recess 517 can be positioned radially outward of the alignment pin 516.

[0098]

[0107] The alignment pin 516 may extend along an edge of the elastic member 514. The alignment pin 516 may be an elongated member. The alignment pin 516 may be substantially parallel to the beam path 535, for example, if provided as part of the elastic member 514A. If the elastic member 514B includes an alignment pin (not shown), it may be formed substantially radially. Thus, the alignment pin may be substantially perpendicular to the beam path 535 (e.g., parallel to the plane 536).

[0099]

[0108] Although resilient members 514 are shown as including alignment pins 516 and support 501 as including corresponding recesses 517, this may be reversed, i.e., resilient members 514 may include recesses and support members may include corresponding alignment pins. In these various configurations, the alignment pins may be used to prevent rotation of the respective resilient members relative to support 501 about beam path 535.

[0100]

[0109] The elastic member 514 may be formed as a single body. In other words, the first type elastic member 514A and / or the second type elastic member 514B may each be provided as a single body. The elastic member 514 may also be provided as a unitary body of one material. Alternatively, the elastic member 514 may be provided as a single body of two or more parts, for example, two parts attached to each other to form a single body. The single body may also be formed by two parts that are different materials from each other. In this way, the elastic member 514 may be formed of two or more different materials.

[0101]

[0110] The elastic member 514 may be provided as two or more bodies, i.e., two or more separate elastic portions. That is, the first type elastic member 514A and / or the second type elastic member 514B may each be provided as multiple bodies. Thus, the elastic member 514 may include, for example, multiple elastic portions positioned annularly (e.g., ring-shaped) around the incidental charged particle beam path 535. For example, the elastic member 514 may be formed from separate portions radially spaced around the feedthrough 522. The elastic member 514 may also include multiple elastic members, which may be positioned to surround the feedthrough 522 in a symmetrical arrangement, e.g., a rotationally symmetrical arrangement. In other words, the multiple elastic members may be positioned to surround the feedthrough 522 at a given distance from the feedthrough 522 and equidistant from each other. In this example, the separate elastic portions of one elastic member 514 may be positioned in a substantially ring-shaped arrangement.

[0102]

[0111] The resilient member 514 may be symmetric. The resilient member 514 may be ring-shaped, otherwise referred to as circular. The resilient member 514 may alternatively have any suitable shape that can be provided around the feedthrough 522. The resilient member 514 may be positioned to be symmetric with respect to the incidental charged particle beam path 535. The resilient member 514 may be positioned to be rotationally symmetric with respect to the incidental charged particle beam path 535, as will be described in more detail below.

[0103]

[0112] The elastic member 514 can be any suitable material. Preferably, the elastic member has a lower thermal conductivity than the thermal conductivity of the material to which it is attached (e.g., support 501) so as to reduce or minimize the transfer of heat across the elastic member 514.

[0104]

[0113] The resilient member 514 may be provided within the support 501. The resilient member 514 may thus provide a component in a mechanical linkage from the detector 531 to a portion of the detector module 500 attached to another component, such as the wall of a vacuum chamber of a secondary column. The feedthrough 522 may be supported by a portion of the support 501 (e.g., the ring 521 connecting with the inner mounting portion 520), and a further portion of the support 501 (e.g., the outer mounting portion 519) may be used for attachment to another portion of the vacuum chamber. For example, as shown in connection with a first type of resilient member 514A, the resilient member 514A may connect a first portion of the support 501 to a second portion of the support 501 to allow movement of the first portion of the support 501 relative to the second portion. For example, the resilient member 514A may be provided to connect the inner mounting portion 520 to the outer mounting portion 519. The resilient member 514 may alternatively (or additionally) be provided between the ring 521 and the inner mounting portion 520. The resilient member 514 may be positioned between any internal component of the support 501 that allows one portion of the support 501 to move relative to another portion of the support 501. In particular, the resilient member 514 may be provided between the feedthrough 522 and a portion of the support 501 that is connected to a component external to the detector module 500.

[0105]

[0114] Additionally or alternatively, the elastic member 514 may be provided as part of a connection between the support 501 and a component external to the detector module 500. For example, as shown in connection with the second type of elastic member 514B, the elastic member 514B may be provided on an outer wall of the support 501. The elastic member 514B may provide a connection between the support 501 and another external component (e.g., part of a vacuum chamber), which may allow the support 501 to move relative to the external component.

[0106]

[0115] The elastic members 514 may be radially compliant, meaning that the elastic members 514 can move in a radial direction. The radial direction may be perpendicular to the incidental charged particle beam path 535, as shown by the first type of elastic member 514A, such that the elastic members 514 can move inward and outward relative to the incidental charged particle beam path 535. In this manner, the elastic members 514A may be configured to move in a radially inward and outward direction in a plane 536 perpendicular to the incidental charged particle beam path 535. In this manner, the elastic members 514 may be used to accommodate radial distortion.

[0107]

[0116] The elastic member 514 may be compliant in the direction of the incidental charged particle beam path 535 (i.e., the elastic member 514 may move in a direction substantially parallel to the incidental charged particle beam path 535), as shown by the second type of elastic member 514B. In this manner, the elastic member 514B may be configured to move in a direction parallel to, i.e., along, the incidental charged particle beam path 535. The support 501 may include a flange 515 for fixing the support 501 to a vacuum wall and / or any component external to the detector module 500. The elastic member 514B may be provided on the flange 515, i.e., on an outer wall of the support 501. The flange 515 may be used to fasten the elastic member 514B.

[0108]

[0117] Only one of the two elastic members 514A and 514B described above may be provided. Alternatively, both elastic members 514A and 514B may be provided. The elastic members 514A and 514B may also be positioned at different parts of the support 501. Each of the elastic members 514A and 514B may be provided at a different position on the support 501.

[0109]

[0118] 4A , the detector module 500 may include a rigid body 511. The rigid body 511 may be attached to a feedthrough 522. The rigid body 511 may be attached to the feedthrough 522 using any suitable connecting material, for example, an adhesive layer. The rigid body 511 may be positioned in the feedthrough 522 on a side of the feedthrough 522 opposite the detector 531. The rigid body may be on a first side 522A of the feedthrough that is suitable for exposure to the atmospheric environment 510.

[0110]

[0119] The rigid body 511 may be configured such that during operation of the detector 531, deformation of the support is symmetrical with respect to the incident charged particle beam path 535, as will be described in more detail below.

[0111]

[0120] Rigid body 511 may provide support to feedthrough 522. This may be beneficial to reduce or prevent deformation of feedthrough 522 due to, for example, a pressure difference between two sides of feedthrough 522. Such a pressure difference occurs when there is a vacuum environment 530 on one side of feedthrough 522 and an atmospheric environment 510 on the other side of feedthrough 522.

[0112]

[0121] The detector module 500 may include a thermal conditioning system. The rigid body 511 may be at least part of the thermal conditioning system. An exemplary thermal conditioning system 650 is shown in more detail in FIG. 7 . The rigid body 511 may be at least part of the thermal conditioning system 650. Cross sections X1, X2, and X3 through the thermal conditioning system 540 of FIG. 7 are provided in FIGS. 8A, 8B, 9A, and 9B. The thermal conditioning system 650 may be an example of an active configuration that can be used to maintain the position of the detector 531 relative to the incident charged particle beam path. As described in connection with the rigid body 511, the thermal conditioning system 650 may be configured such that deformation of the support 501, e.g., due to thermal fluctuations, is symmetrical relative to the incident charged particle beam path 535 during operation of the detector 531.

[0113]

[0122] The alignment and adjustment achieved by conditioning the system using the thermal conditioning system 650 can be applied at a specific temperature and / or under specific conditions. For example, alignment and adjustment achieved at a certain temperature, e.g., during a detection operation, can be maintained during a specific operation, e.g., a maintenance operation, in which a disturbance, such as pressure and / or heat, is applied to the detector module. Then, when such a temperature disturbance is removed, e.g., when returning from a maintenance operation to a detection operation, the detector maintains its position, and if the detector's position shifted between the detection operation and the maintenance operation, the shift is reversed, changing the state of the detector module for the detection operation. The thermal conditioning system 650 can be configured to thermally condition the detector during a specific operation, e.g., a detection operation. In this case, the thermal conditioning system can be configured to position the detector in the same position during the detection operation (despite any position changes that may occur during the maintenance operation), as described above.

[0114]

[0123] The thermal conditioning system 650 can be beneficial in providing uniform distribution and stable thermal conditioning. The thermal conditioning system 650 can be beneficially provided to fit into limited spaces, such as in combination with a secondary column. As discussed above, heat can be generated at least by the electronics (which can preferably be proximate to the detector 531) and by interactions of the detector 531 with incident charged particles (e.g., during operation of the detector 531), and as a result, the thermal conditioning system 650 can beneficially reduce or prevent inaccurate positioning that would otherwise occur as a result of thermal loading. Thus, the thermal conditioning system 650 can be beneficial in reducing or avoiding distortions resulting from thermal loading and can be used to maintain the position of the detector 531 relative to the incident charged particle beam path 535.

[0115]

[0124] The thermal conditioning system 650 may deliver and withdraw conditioning fluid to the portion of the detector module 500 including the detector 531 such that the position of the continuous duct or ducts of the thermal conditioning system 650 does not interfere with other components forming the associated circuit, such as the elastic member 514, if present. The thermal conditioning fluid may have a relatively high heat capacity, such as water. Preferably, the thermal conditioning system 650 is provided such that it can thermally condition the support 501 and / or the detector 531 while allowing electronics access to the detector 531. Preferably, the thermal conditioning system is operative at least during detection operation.

[0116]

[0125] The thermal conditioning system 650 may be, for example, a fluid conditioning system that uses a conditioning fluid. The thermal conditioning system may be configured to thermally condition the support 501. The thermal conditioning system 650 may additionally or alternatively be configured to, at least indirectly, thermally condition the detector 531. The thermal conditioning system 650 may be configured to transfer heat from the support 501. The thermal conditioning system may be configured to transfer heat from the support 501, and thereby transfer heat from the detector 531. Various configurations may be used for the thermal conditioning system 650.

[0117]

[0126] Preferably, the thermal conditioning system 650 provides thermal conditioning of the support 501 and / or the detector 535 so that deformation of the support 501 is symmetric with respect to the incident charged particle beam path 535 and preferably to reduce or limit distortion of the support 501 induced by, for example, a disturbance, e.g., a thermal disturbance. If thermal conditioning is not applied, the deformation may exceed a thermal threshold below which the disturbance will be substantially symmetric and, therefore, without thermal conditioning, asymmetric deformation due to thermal disturbance may be more likely.

[0118]

[0127] For example, the thermal conditioning system 650 may supply fluid in a symmetrical and / or uniform manner over the feedthrough 522. The thermal conditioning system 650 may supply fluid over a central portion of the feedthrough 522. The central portion of the feedthrough 522 may correspond to the region where the charged particle beam is directed and / or the region where the detector 531 is positioned. Preferably, the thermal conditioning system 650 supplies fluid over the location of the detector 531, e.g., the side of the feedthrough opposite the detector 531. This is beneficial in providing thermal conditioning to portions of the feedthrough that may experience a large thermal load due to the proximity of the detector 531. Preferably, the thermal conditioning system supplies fluid uniformly over the location of the detector 531. The feedthrough 522 is configured to conduct heat therethrough to ensure that the detector 531 is conditioned. This may be accomplished by selecting a material for the feedthrough 522 that has good thermal conductivity. Alternatively or additionally, the feedthrough 522 may include a thermally conductive structure therethrough that conducts heat from one side of the feedthrough 522 to the other side of the feedthrough 522. For example, such a thermal conditioning structure may be electrical wiring within the feedthrough 522.

[0119]

[0128] Thermal conditioning system 650 may include a supply connection 651 and / or a return connection 652. Supply connection 651 may be in the form of a connection through which fluid is provided / delivered during use. More specifically, supply connection 651 may be used to supply fluid for thermally conditioning feedthrough 522. Return connection 652 may be in the form of a connection through which fluid is returned during use. More specifically, fluid used to thermally condition feedthrough 522 may be returned via the return connection.

[0120]

[0129] Preferably, there is a single supply connection 651 and / or a single return connection 652, as this is less likely to experience turbulence. However, it should be noted that multiple supply connections 651 and / or multiple return connections 652 may be provided and are interchangeable with any reference to a single supply connection 651 and / or return connection 652.

[0121]

[0130] The supply connection 651 and the return connection 652 can be positioned in a variety of different ways. The supply connection 651 and the return connection 652 can be positioned on the same side of the feedthrough 522, more specifically in the atmospheric environment 610. The supply connection 651 and the return connection 652 can be positioned symmetrically with respect to the support 501. The supply connection 651 and the return connection 652 can be positioned on opposite sides of the geometric axis of the support with respect to the direction of the secondary beam path. The supply connection 651 and the return connection 652 can be positioned in a central region of the feedthrough 522. The supply connection 651 and the return connection 652 can be located at a radially outer position compared to the incidental charged particle beam path 535. The supply connection 651 and the return connection 652 can be positioned symmetrically with respect to a plane containing the incidental charged particle beam path 535, which plane is perpendicular to the feedthrough 522.

[0122]

[0131] Such a thermal conditioning system is likely to generate and propagate vibrations along the fluid conditioning path. Additionally, electronics that may be associated with (e.g., thermally conditioned by) part of the thermal conditioning system 650 may also generate vibrations. The conditioning fluid may be an incompressible fluid (e.g., water) that tends to propagate vibrations. Having connections on both sides (i.e., supply connection 651 and return connection 652 positioned symmetrically and / or opposite each other as described above) means that the sides of such vibrations are "balanced"—equal and opposing forces applied at the extremes and positioned equally far from the axis and / or path. Thus, vibrations will be applied more symmetrically around the support than would be the case without such measures.

[0123]

[0132] The thermal conditioning system 650 may additionally define at least a portion of a channel 653, as shown in FIGS. 7, 8A, and 8B. The channel 653 may alternatively be referred to as a conduit or a duct. The thermal conditioning system 650 may be configured to provide a conditioning fluid through the channel 653 to thermally condition the feedthrough 522. The thermal conditioning system 650 may be configured to provide uniform and stable thermal conditioning through the channel 653. This may be improved by the positioning of the fluid supply connection 651, the fluid return connection 652, and / or the shape of the channel 653. As described, the thermal conditioning system 650 may be configured to provide a conditioning fluid through the channel 653 to transfer heat from the feedthrough 522. Preferably, during operation of the detector module 500, deformation of the support 501 due to, for example, thermal fluctuations, is symmetrical with respect to the incidental charged particle beam path 535.

[0124]

[0133] The channels 653 may be positioned relative to the feedthrough 522 to affect how heat is transferred from the feedthrough 522. Preferably, thermal conditioning using the channels 653 may allow deformation of the support 501 relative to the incident charged particle beam path 535 to be symmetrical.

[0125]

[0134] Thermal conditioning system 650 may define at least a portion of channel 653. Thus, channel 653 may be part of thermal conditioning system 650. Channel 653 may be positioned adjacent to feedthrough 522. Channel 535 may be formed internally of thermal conditioning system 650. Channel 535 may be formed internally of rigid body 511. Alternatively, channel 653 may be partially formed by feedthrough 522; for example, if feedthrough 522 provides at least a portion of the walls of channel 653, rigid body 511 may form a portion of the walls of channel 653. Thus, channel 653 may be formed in a combination of thermal conditioning system 650 (and specifically rigid body 511) and feedthrough 522. In this case, the walls of channel 653 may be provided by thermal conditioning system 650 (and specifically rigid body 511) and feedthrough 522.

[0126]

[0135] The channel 653 may be positioned in a central region of the feedthrough 522. The channel 653 may be positioned on the feedthrough 522 opposite the detector 531, which is mounted on the opposite side of the feedthrough 522 (even if provided in the thermal conditioning system 650 or the rigid body 511). The channel 653 may have any suitable shape. For example, the channel 653 may be provided in a curved path shape, as shown in either FIG. 8A or 8B, which are cross-sectional views through X1 in FIG. 7. Preferably, the channel 653 is provided in a sinusoidal shape, such as a sigmoidal curve shape, otherwise sometimes referred to as an S-shape, as shown in FIG. 8B. Preferably, the channel 653 is formed to provide laminar flow within the channel 653, i.e., to reduce or avoid turbulent flow. This may be achieved by selecting a shape for the channel 653 that has smooth sides and / or curves and avoids sharp corners within the channel 653. Laminar flow is preferable to turbulent flow, as turbulent flow can cause disturbances during detector operation. The shape of the channel 653 is discussed further below.

[0127]

[0136] The thermal conditioning system 650 may include a rigid plate. The rigid plate may be useful in providing support to the feedthrough 522 and / or functioning as a heat spreader. The rigid plate may be part of or integrated with the rigid body 511. The rigid plate may replace the rigid body 511 shown in FIG. 8A or 8B. The channel 653 may be formed on or as part of the rigid plate. The rigid plate may contact or be adjacent to the feedthrough 522. The rigid plate may contact or be adjacent to the side of the feedthrough 522 opposite the device 531 (i.e., the first side 522A of the feedthrough 522). Thus, the rigid plate may be close to the detector 531. The feedthrough 522 may be sandwiched between the rigid plate and the detector 531, for example. Preferably, the rigid plate is positioned outside the vacuum chamber environment 530. The rigid plate may be beneficial in providing mechanical support to reduce or prevent deformation of the detector 531 and / or the feedthrough 522 due to, for example, pressure differences within the detector module. The thermal conditioning system 650 may be configured to provide uniform and stable thermal conditioning on the plate, which may be beneficial in providing uniform and stable conditioning of the feedthrough 522. The channel 653 may be in direct contact with the rigid plate. Alternatively, the thermal conditioning system 650 may not include a rigid plate.

[0128]

[0137] The detector module 500 may further include an electronics unit 670. The electronics unit 670 may include electronics configured to be in signal communication with the detector 531, for example, to control the detector 531 and / or receive data from the detector 531. At least the electronics unit 670 may include a connection to the support 501. Similarly, the support 501 may include a connection to the electronics unit 670. The connection between the electronics unit 670 and the support 501 may function as a plug and socket arrangement.

[0129]

[0138] Preferably, electronics unit 670 is supported by support 501 and / or thermal conditioning system 650, for example, at least during maintenance operations. Preferably, electronics unit 670 is spaced apart from support 501, optionally located near support 501. For example, electronics unit 670 may be attached to or connected to a part of thermal conditioning system 650 and held in place by thermal conditioning system 650 (e.g., housing 680 of thermal conditioning system 650). Thus, electronics unit 670 may be spaced apart from detector (attached to a part of the support) and / or feedthrough 522 (which is part of the support). Spaced apart electronics unit 670 from support 501 is beneficial because it reduces or avoids forces exerted by electronics unit 670 (e.g., due to thermal fluctuations) from affecting support 501 and thus detector position 531. Such forces may be a type of disturbance force. The source of such a force may be stress applied between the electronics and the support 501 when they come into contact due to thermal differences between them. The electronics may be an additional thermal load, and directly connecting their support structure risks transferring heat generated by the electronics during operation directly to the detector. Separating them contributes to thermal insulation. In view of the conditioning fluid passing through the thermal conditioning system, separating the electronics from the detector helps reduce, if not prevent, any vibrations in the electronics unit, such as those generated in the fluid conditioning system, from being transferred to the detector. The electronics unit 670 and / or the electrical connections connecting to the electronics unit 670 may be positioned symmetrically with respect to the incident charged particle beam path. A symmetrical arrangement, e.g., given the symmetrical design of the support 501, may reduce the transmission of disturbances, such as vibrations, toward the detector.

[0130]

[0139] Preferably, the electronics unit 670 is as close as possible to the detector 531 to provide a shorter signal path, thereby reducing attenuation of the signal from the detector 531 to, for example, the electronics unit to which the detector is electrically connected. Of course, this will be limited by other components provided as part of the detector module 500.

[0131]

[0140] The electronics unit 670 can be provided with any of the embodiments described herein. When provided in an embodiment including a thermal conditioning system 650, the thermal conditioning system 650 can be configured to thermally condition the electronics unit 670 in addition to or instead of other components that may be thermally conditioned by the thermal conditioning system 650. The thermal conditioning system 650 can be configured to transfer heat from the electronics unit 650. The location of the fluid supply connections 651 and / or fluid return connections 652 on the feedthrough can be selected to allow electrical connections to be provided on the feedthrough 522. The detector module 500 can be configured to provide electronic connections (e.g., for connecting to the electronics unit 670) and thermal conditioning connections on the same side of the feedthrough 522. The detector module 500 can be configured to provide the electronic connections and fluid conditioning connections proximate to the detector 531 (on the opposite side of the feedthrough from the detector). Preferably, this means that the electrical and fluid supply connections are as close as possible to the detector 531 and can fit among the other components and connections. Furthermore, this allows for a smoothly curved flow path for the conditioning fluid, as shown in Figures 7, 8A, 8B, and 9A, which can reduce the generation of vibrations due to turbulence.

[0132]

[0141] Reference is now made to FIG. 5, which is a schematic diagram illustrating an exemplary vacuum system 300 that is part of the exemplary multi-beam system of FIG. 2 and / or FIG. 3, consistent with embodiments of the present disclosure. The description associated with FIG. 5 provides embodiments and details of the detector module 300. The details shown and described in connection with FIG. 5 may be used in combination with the details described above in connection with the previous figures. In other words, the features shown and described in connection with FIGS. 4A and 4B above are interchangeable with the features shown and described in connection with FIGS. 5 and / or 6 below.

[0133]

[0142] The vacuum system 300 may include an atmospheric environment 310 and a vacuum chamber environment 330, with a boundary 320 indicating the boundary between the atmospheric environment 310 and the vacuum chamber environment 330. The vacuum system 300 may correspond to a variation of the detector module 500 described above. The atmospheric environment 310 may be the same as the atmospheric environment 510 described above. The vacuum chamber environment 330 may be the same as the vacuum chamber environment described above. The detector module 500 may include the boundary 320 as described in connection with FIG. 5 . Note that the boundary 320 is used for illustrative purposes and is not physically part of the vacuum system. A PCB 322 may be provided. The PCB 322 described herein may correspond to a variation of the feedthrough 522 described above. The PCB described herein may be replaced with a more general feedthrough 522. The feedthrough 522 may include any or all of the features described in connection with the PCB 322. The PCB 322 may be disposed on the boundary 320 to form an interface between the atmospheric environment 310 and the vacuum chamber environment 330 such that the vacuum chamber environment 330 is sealed, thereby advantageously preventing contaminants (e.g., water vapor, air molecules, etc.) from leaking into the vacuum chamber environment 330. For example, a first side of the PCB 322 may be exposed to the atmospheric environment 310, while a second side of the PCB 322 opposite the first side may be exposed to the vacuum chamber environment 330. The first side of the PCB may correspond to the first side 522A of the feedthrough, and the second side of the PCB may correspond to the second side 522B of the feedthrough. The hermetic seal provided by the PCB 322 prevents contaminants from entering the vacuum chamber environment 330, thereby allowing the vacuum chamber environment 330 to reach a predetermined pressure in a shorter time, thereby increasing the throughput of the inspection system. Additionally, the hermetic seal provided by PCB 322 may extend the life of the inspection system by preventing contaminants from contacting components within the vacuum chamber environment 330 (e.g., pure aluminum components, high voltage components, charged particle source components, etc.).

[0134]

[0143] A device 331 may be provided in an aperture of the ring 321 on the second side of the PCB 322. The device 331 is a more generalized version of the detector 531, which may be more generally provided as the device 331. The detector 531 and the device 331 may be interchangeable. The PCB 322 may cover the aperture of the ring 321 such that the device 331 is provided and operates while exposed to the vacuum chamber environment 330. The ring 321 may correspond to the ring 521 described above in connection with the support 501. In some embodiments, the PCB 322 covering the aperture of the ring 321 may include the PCB 322 filling the aperture of the ring 321. The device 331 may be a component of the electron beam tool 104 of FIG. 3 (e.g., the detection device 240 of FIG. 3). In some embodiments, the device 331 may be directly connected to the second side of the PCB 322. The device 331 may include multiple devices, which may be the same device or may be various different devices. The hermetic seal provided by PCB 322 may extend the life of device 331 by preventing contaminants from atmospheric environment 310 from entering vacuum chamber environment 330 and contacting device 331 .

[0135]

[0144] PCB 322 may include a material that can reduce or minimize thermal resistance between device 331 and PCB 322. For example, PCB 322 may include a material (e.g., an insulator, ceramic, alumina, SiN, etc.) that has a coefficient of thermal expansion (CTE) substantially similar to that of device 331 (e.g., the CTE of PCB 322 may be similar or identical to that of device 331). CTE measures the change in size of a material per degree change in temperature. Therefore, selecting a material for PCB 322 that has a CTE at least similar to that of device 331 may advantageously reduce distortion in PCB 322 and device 331, thereby maintaining the quality of the inspection system after high-temperature processes (e.g., bake cycles). For different applications, PCB 322 may have different shapes (e.g., circular, hexagonal, rectangular, etc.) when viewed in the y-direction to enhance the interface between air environment 310 and vacuum chamber environment 330.

[0136]

[0145] In some embodiments, a rigid body 311 for exposing the PCB 322 to the atmospheric environment 310 may be provided on a first side of the PCB 322 so that the PCB 322 is attached to the rigid body 311. The rigid body 311 may correspond to the rigid body 511 described above, and they are interchangeable. The rigid body 311 may extend over the walls of the ring 321 (e.g., the walls of the ring 321 may be a material that forms an aperture in the ring 321, or a material may surround the aperture in the ring 321) so that the rigid body 311 provides mechanical support to the PCB 322 to enhance the airtight seal provided by the PCB 322, thereby enabling the PCB 322 to withstand vacuum forces from the vacuum chamber environment 330. For example, a force acting on the rigid body 311 due to gravity (e.g., the mass of the rigid body 311) may be a downward force exerted on the PCB 322 and the walls of the ring 321. The mass of rigid body 311 may be greater than the mass of PCB 322 so that gravity acting on rigid body 311 can provide mechanical support to PCB 322 and enhance the hermetic seal provided by PCB 322. In some embodiments, rigid body 311 may include multiple rigid bodies. In some embodiments, electrical connection 312 may be positioned on a first side of PCB 322. Electrical connection 312 may correspond to, and be interchangeable with, electrical connection 512 described above. Electrical connection 312 may be electrically connected to device 331 by PCB 322. In some embodiments, electrical connection 312 may include multiple electrical connections.

[0137]

[0146] Rigid body 311 may be at least part of thermal conditioning system 650 as described above and may have any of the variations described above. Rigid body 311 may be a cooling system (e.g., a liquid cooling system, a natural air cooling system, a forced air cooling system, a Peltier cooling system, etc.) that may be configured to transfer heat between rigid body 311 and device 331. For example, PCB 322 may be configured to provide an interface between rigid body 311 and device 331. In some embodiments, PCB 322 may be configured to provide a thermal connection between rigid body 311 and device 331 such that during a high-temperature process or other process in which device 331 (e.g., an opto-electrical component such as a position sensor, a mirror, a motor, a detector, etc.) dissipates heat during testing, heat is transferred between rigid body 311 and device 331 or vacuum chamber environment 330 through PCB 322, thereby preventing premature failure of device 331 or other components due to excessive heat exposure. The rigid body 311 may advantageously prevent catastrophic errors during manufacturing or testing by transferring heat away from the device 331 and preventing failure. For example, even small changes in temperature exposure to the device 331 (e.g., the detection device 240 of FIG. 3 ) can reduce the collection efficiency of signal electrons, such as secondary electrons (SEs) and backscattered electrons (BSEs), and thus adversely affect throughput and testing yield. Furthermore, the rigid body 311 advantageously occupies less space in the inspection system than separate cooling feedthroughs and provides more structural symmetry, which may reduce the need for adjustments of the inspection system during high-temperature processes, thereby reducing stage position errors and beam placement accuracy errors.

[0138]

[0147] In some embodiments, to enhance the hermetic seal provided by the PCB 322 and the rigid body 311, a sealing layer 332 (e.g., solder) may be provided between the wall of the ring 321 and the second side of the PCB 322. The sealing layer 332 may include at least one sealing layer and may be provided on one side of the PCB 322 such that the sealing layer 332 is disposed between the wall of the ring 321 and the second side of the PCB 322. The sealing layer 332 may also be provided in the detector module 500 described above.

[0139]

[0148] In some embodiments, PCB 322 may include multiple layers. Each of the multiple layers may include at least one via or trace to provide electrical connection between electrical connection 312 and device 331. Each via may be filled with a conductive material and may extend in the y-direction through a portion, but not all, of PCB 322 to prevent leakage between air environment 310 and vacuum chamber environment 330 and to provide a shorter signal path, thereby reducing attenuation of signals from device 311. Each trace of PCB 322 may be configured to maintain signal integrity, such as to form a transmission line for routing high-speed signals between electrical connection 312 and device 331. PCB 322 may include grounding and shielding structures in multiple layers.

[0140]

[0149] In some embodiments, the vacuum system 300 (and / or the detector module 500) may include structural components such as fixed, stable, resilient, and / or sealing elements, such as (in a non-limiting list) clamping ring 313, flexible element 314, flange 315, or O-ring 323, that provide additional mechanical support to the PCB 322 and enhance the hermetic seal between the atmospheric environment 310 and the vacuum chamber environment 330. For example, the flexible element 314 may be a bearing that inhibits relative motion and reduces friction between moving parts within the vacuum system 300. The flexible element 314 may be an example of an elastic member 514. Because the flexible element 314 has no moving parts, it provides high stiffness and high load capacity with minimal wear, thereby providing mechanical support to the PCB 322 and reinforcing the hermetic seal provided by the PCB 322.

[0141]

[0150] Reference is now made to Figure 6, a flowchart illustrating an exemplary process 400 for sealing a vacuum system consistent with embodiments of the present disclosure. A similar process may be used for the detector module 500.

[0142]

[0151] In step 401, a PCB (e.g., PCB 322 in FIG. 5) may be formed that includes a first side for exposure to an atmospheric environment (e.g., atmospheric environment 310 in FIG. 5) and a second side for exposure to a vacuum chamber environment (e.g., vacuum chamber environment 330 in FIG. 5) and for covering an aperture in the vacuum chamber environment (e.g., aperture in ring 321 in FIG. 5), the second side being opposite the first side.

[0143]

[0152] In step 403, an interface between the device (e.g., device 331 in FIG. 5 ) and the rigid body (e.g., rigid body 311 in FIG. 5 ) may be provided using a PCB, with the rigid body on a first side of the PCB for exposure to the atmospheric environment and the device connected to a second side of the PCB and positioned within the aperture. The device may be a component (e.g., detection device 240 in FIG. 3 ) of an electron beam tool (e.g., electron beam tool 104 in FIG. 3 ). For example, the PCB may hermetically seal a vacuum chamber. In some embodiments, a sealing layer (e.g., sealing layer 332 in FIG. 5 ) may be provided between the wall of the ring and the second side of the PCB to reinforce the hermetic seal provided by the PCB. The sealing layer may include at least one sealing layer and may be provided on one side of the PCB such that the sealing layer is positioned between the wall of the ring and the second side of the PCB. In some embodiments, the rigid body may provide mechanical support to the PCB such that the PCB may hermetically seal a vacuum chamber environment without any sealing layer between the wall of the ring and the PCB.

[0144]

[0153] In step 405, the device may operate within a vacuum system. The airtight seal provided by the PCB may prevent contaminants from entering the vacuum chamber environment from the ambient air, thereby potentially extending the life of the device or other components of the system. The rigid body may include a cooling system (e.g., a liquid cooling system, a natural air cooling system, a forced air cooling system, a Peltier cooling system, etc.) configured to transfer heat between the rigid body and the device. For example, PCB 322 may be configured to provide an interface between the rigid body and the device. In some embodiments, the PCB may be configured to provide a thermal connection between the rigid body and the device such that during high-temperature processes or other processes in which the device (e.g., optoelectronic components such as position sensors, mirrors, motors, detectors, etc.) dissipates heat during testing, heat may be transferred through the PCB between the rigid body and the device or the vacuum chamber environment, thereby preventing premature failure of the device or other components due to excessive heat exposure.

[0145]

[0154] A thermal conditioning system 650 can be provided in any of the embodiments and variations described above. The thermal conditioning system 650 can be used to condition at least a portion of the detector module 500, and more particularly at least a portion of the support 501. In one arrangement, the thermal conditioning system 650 is part of the detector module 500. In one embodiment, the thermal conditioning system 650 can be operated during operation of the detector 531. As described above, this can be beneficial in controlling thermal fluctuations and temperatures in at least a portion of the detector module 500.

[0146]

[0155] In one embodiment, the thermal conditioning system 650 includes a support thermal conditioning section (e.g., including a first circuit 654, described below) configured to thermally condition the support. The thermal conditioning system 650 may include an additional thermal conditioning section (e.g., including a second circuit 655, described below) configured to thermally condition another portion of the detector module 500. In other words, the thermal conditioning system may include at least two sections configured to thermally condition at least primarily two different portions of the detector module 500, such as the support 501 and another portion of the detector module 500.

[0147]

[0156] In one embodiment, a detector module 500 is provided, for example, as shown in FIG. 7 . In this embodiment, the detector module 500 includes a conditioning module 650 that includes two portions: a non-separable portion 675 for conditioning the feedthrough 522 and the detector 531, and a separable portion 676 for positioning or locating the detector 531 and electronics 670 in proximity to the electronics conditioning section. The separable portion 676 is distinguished from the non-separable portion 675 by a dashed line 677 in FIG. 7 . The non-separable portion 675 may correspond to a support thermal conditioning section. The separable portion 676 may correspond to a further thermal conditioning section.

[0148]

[0157] The detachable portion 676 is configured to be removable from the detector module 500. In other words, the detachable portion 676 can be removed, i.e., detached, from the detector module 500 and reattached to the detector module 500. The detachable portion 676 can be detached and attached without damaging the components of the detector module. The detachable portion 676 can be connected to other portions of the detector module 500 via detachable connections. The detachable portion 676 can be easily detached and attached to the rest of the detector module 500. The detachable portion 676 can be detached during certain operations, for example, maintenance operations such as bakeout.

[0149]

[0158] Providing thermal conditioning system 650 with detachable portions 676 is particularly beneficial because some components of detector module 500 (such as electronics) may be more susceptible to damage due to thermal fluctuations that may occur during certain stages of operation of detector module 500, e.g., maintenance operations such as bakeout. For example, during bakeout, the entire detector module 500 is heated to high temperatures, and removal of certain components (i.e., detachable portions) protects them from these high temperatures.

[0150]

[0159] Furthermore, having the detachable portion 676 provides greater design flexibility for other portions of the thermal conditioning system 650, since heat-sensitive components can be removed from the detector module 500 during portions of its operation, such as during maintenance operations, e.g., bakeout. This means that the other portions of the detector module 500 (which are removed along with the detachable portion) do not need to be designed to withstand processing conditions such as high temperatures. Thus, the design of the other (detachable / separable) portions can be relaxed, e.g., to allow the use of standard materials and processes.

[0151]

[0160] The thermal conditioning system 650 may include at least two thermal conditioning circuits, which may be arranged sequentially with respect to the flow of conditioning fluid. Each circuit includes components through which the conditioning fluid can pass. Thus, each circuit is used to form a fluid path. For example, each circuit includes at least one duct or conduit for passing the conditioning fluid. The path along which the conditioning fluid passes within the circuit is a fluid path. The conditioning circuits may be connected in series, i.e., as a cascading fluid path. Components requiring more stringent thermal conditioning are preferably upstream of components with lower thermal conditioning. Each thermal conditioning circuit may be provided in a different thermal conditioning section.

[0152]

[0161] One of the thermal conditioning circuits may be part of a separable portion 676, i.e., may be removable. As described in more detail below, the thermally conditioned detector 531, which may operate in a vacuum environment, may be positioned below the first circuit 654. Other components of the detector module 500, such as the electronics unit 670, may be thermally conditioned by the second circuit 655. The first circuit 654 and / or the second circuit 655 may be provided as a loop adjacent to and / or surrounding the component thermally conditioned by that circuit.

[0153]

[0162] The separable portion 676 may be removable by at least one connection between the separable portion 676 and other components of the detector module 500. The separable portion 676 may include a further thermal conditioning section (including at least the second circuit 655) and other portions, i.e., other portions of the detector module 500 that are thermally conditioned by the further thermal conditioning section. Thus, the thermal conditioning system 650 may be provided in two sections, one of which can remain in place during operation of the detector module 500 and the other of which can be removed along with the portion that is thermally conditioned by the removable portion of the thermal conditioning system 650.

[0154]

[0163] For example, the other portion can be electronics unit 670. Electronics unit 670 is described above and is configured to signal communicate with detector 531 to control and / or receive data from detector 531. It is particularly beneficial to provide the electronics unit as at least part of another portion of a separable module, sometimes referred to as a conditioning module (i.e., as part of separable thermal conditioning system 650). This allows electronics unit 670 to be located near detector 531 when separable module 676 is positioned within detector module 500, while still allowing electronics unit 670 to be removed when conditions within detector module 500 may negatively affect electronics unit 670, such as during high temperature periods, e.g., bakeout. This is further beneficial in allowing other components to remain part of detector module 500, e.g., thermal conditioning system 650, so that fluid paths to the feedthroughs can be maintained. Additionally, this may be beneficial in maintaining other components of the detector module in place 500, thereby reducing the likelihood of the detector being displaced relative to the incident charged particle beam path 535.

[0155]

[0164] The detachable portion 676 may include all external heat conditioning connections, so that all external heat conditioning connections can be removed along with the detachable portion 676 .

[0156]

[0165] The separable portion 676 is further beneficial in addressing issues related to the limited space available for the detector module 500. Considering the interaction of the detector 535 with incident charged particles (i.e., signal particles) during detection operations, heat can be generated. This is the case when the detector module 500, including the fluid conditioning system 650, is assembled. Although heat is also generated by the electronics unit 670, the electronics unit is still preferably located close to the detector 535 to reduce or minimize detector signal attenuation. Failure to address the effects of heat load can adversely affect the positioning of the detector 535 and the performance of the electronics. Therefore, this can generally be addressed by the thermal conditioning system 650. However, the electronics can still be adversely affected during high thermal loads applied during bakeout. Therefore, providing the electronics unit 670 within a separable portion allows for proximity (and therefore space-saving positioning) of the electronics unit, which reduces signal attenuation, without requiring the electronics unit 670 to remain in place to withstand higher thermal loads, such as during bakeout.

[0157]

[0166] Additionally or alternatively, the electronics unit 670 may be separable from other components of the detector module 500. This may mean that the electronics unit 670 can be disconnected from the detector module 500, and in particular from the thermal conditioning system 650, if relevant, and easily reattached when needed. For example, it may be beneficial to remove the electronics unit 670 during bakeout to avoid adversely affecting the electronics unit 670 from high temperatures reached during bakeout. The electronics unit 670 may be separable with or without other components of the detector module 500, and more specifically, with or without other components of the thermal conditioning system 650. To simplify removal of the electronics unit 670, which may be more affected (e.g., by thermal fluctuations) than other components, it may be preferable to remove the electronics unit 670 without the other components.

[0158]

[0167] The support thermal conditioning section may include a first fluid path, i.e., a first fluid path within first circuit 654. The further thermal conditioning section may include a second fluid path, i.e., a second fluid path within second circuit 655. Each thermal conditioning section may include at least one fluid path having at least one fluid duct forming a circuit of the fluid path.

[0159]

[0168] Preferably, the support thermal conditioning section includes a first circuit 654 including a fluid supply duct 656 and a fluid return duct 657. Thus, the support thermal conditioning section may supply conditioning fluid via fluid supply duct 656 and return conditioning fluid via fluid return duct 657. A further thermal conditioning section may include a second circuit 655 that may include duct 658. Fluid supply duct 656 and fluid return duct 657 are both shown in FIG. 7 and are also shown in FIGS. 9A and 9B, which are cross-sectional views at X2 and X3, respectively, as shown in FIG. 7.

[0160]

[0169] 9A, the fluid supply duct 656 and the fluid return duct 657 may be symmetrical in a plane (represented by line P1) perpendicular to the feedthrough. The fluid supply duct 656 and the fluid return duct 657 may be symmetrical in a further plane (represented by line P2) perpendicular to the feedthrough and plane (P1). The electrical connection 512 may be symmetrical in a plane (represented by line P1) perpendicular to the feedthrough. The electrical connection 512 may be symmetrical in a further plane (represented by line P2) perpendicular to the feedthrough and plane (P1). The fluid supply duct and the fluid return duct may be symmetrical in the same plane (or even the same plane) as the electrical connection 512, but these components may be symmetrical with respect to different planes.

[0161]

[0170] Each circuit may include a single duct. Alternatively, at least one of the circuits may include multiple ducts, including two or more ducts. Ducts may alternatively be referred to as conduits, pipes, or piping. The ducts may be positioned such that the circuits lie within a particular plane and / or are symmetrical relative to a particular plane and / or component of the detector module 500, as described in more detail below.

[0162]

[0171] The ducts may be formed of any suitable material. For example, the fluid supply duct 656 and / or the fluid return duct 657 may be flexible. This may be beneficial in reducing forces transmitted to the support 501 through the flexible ducts. In particular, flexibility may be beneficial in aiding in the damping of any vibrations generated within the fluid conditioning system 650 and transmitted therefrom toward the detector 531. This may be beneficial in isolating force paths from the thermal conditioning system 650 to reduce or prevent components of the thermal conditioning system 650 from adversely affecting the detector 531. The duct 658 forming the second fluid path may be rigid.

[0163]

[0172] Preferably, thermal conditioning system 650 is supported on a radially outer portion of support 501. For example, a portion of thermal conditioning system 650 may be connected to a portion of support 501. Preferably, the force exerted by thermal conditioning system 650 is directed to an outer portion of support 501 rather than an inner portion of support 501 where detector 531 may be mounted. For example, a portion of thermal conditioning system 650 may be mounted to an outer portion of support 501, i.e., a portion of support 501 that indirectly, i.e., does not directly, contact the radially outer side of feedthrough 522 and / or ring 521. More specifically, a portion of thermal conditioning system 650, such as housing 680, may be mounted to inner mounting portion 520 and / or outer mounting portion 519.

[0164]

[0173] Preferably, the thermal conditioning system 650 is supported by a housing 680. While the housing 680 is shown as circular in FIG. 9B , it may be any suitable shape, e.g., hexagonal, rectilinear, oval, etc. A hexagonal shape for the housing may be beneficial for ease of manufacturing (e.g., using sheet metal bending techniques) and / or to provide flat areas on the housing for mounting other components. The housing 680 is configured to enclose at least a portion of the thermal conditioning system. Preferably, the housing 680 supports the components of the thermal conditioning system 650. Preferably, the housing 680 is connected to a radially outer portion of the support 501, such as the inner mounting portion 520 and / or the outer mounting portion 519. This is beneficial for isolating force paths from the thermal conditioning system 650 to reduce or prevent the components of the thermal conditioning system 650 from adversely affecting the detector 531.

[0165]

[0174] The thermal conditioning system 650 , preferably the housing 680 , may include a mounting flange 681 that can be used to attach the thermal conditioning system 650 to other components of the detector module 500 , preferably the support 501 .

[0166]

[0175] The first fluid path and the second fluid path may be in fluid communication. Thus, a conditioning fluid may flow from the first fluid path to the second fluid path. Additionally or alternatively, a conditioning fluid may flow from the second fluid path to the first fluid path. This is beneficial in that the conditioning fluid used for thermal conditioning in a thermal conditioning section (e.g., a support thermal conditioning section and a further thermal conditioning section) may be used in multiple thermal conditioning sections to improve the efficiency and / or reduce the complexity of the thermal conditioning system 650 (e.g., by using one pump (not shown) for multiple thermal conditioning sections). The first fluid path and / or the second fluid path may be referred to as a series fluid path and / or a cascade fluid path.

[0167]

[0176] The first and second fluid paths may be in fluid communication through a connecting portion 660. The connecting portion 660 may be removed to disconnect the first and second fluid paths. The connecting portion 660 may be a duct. The connecting portion 660 may be referred to as a loop. The connecting portion 660 may be external to the housing 680 (if provided). This may be beneficial to allow for quick assembly and disassembly.

[0168]

[0177] The detector module 500 may include a closable valve 695 between the first circuit 654 and the second circuit 655 that can be used to control the flow of fluid between the first and second fluid paths and vice versa. For example, when the separable portion of the detector module 500 is in place, the valve 695 can be opened to allow thermal conditioning fluid to pass between the first and second fluid paths and vice versa. When the separable portion is removed from the detector module 500, the valve 695 can be closed to prevent the passage of fluid between the first and second fluid paths. Thus, the valve 695 can be used to close the ends of the first and / or second fluid paths. This can prevent fluid leakage when the separable portion is removed from the detector module 500. The valve 695 can be provided in any suitable location that separates the first and second circuits 654 and 655.

[0169]

[0178] Alternatively, the first circuit 654 and the second circuit 655 may be provided as separate loops. In other words, the first fluid path may use a first conditioning fluid, and the second fluid path may use a second conditioning fluid. In this manner, separate circuits with separately controlled fluids may be provided to thermally condition different portions of the detector module 500. This may make removal of the separable portion simpler. Furthermore, this may allow for continuous use of the first fluid path during maintenance operations in which the separable portion is removed.

[0170]

[0179] Preferably, all thermal conditioning (in any of the embodiments) is stopped during maintenance operations requiring extreme conditions such as bakeout, regardless of whether any components are removed, although thermal conditioning during maintenance operations may be performed, for example, when a separable part is removed.

[0171]

[0180] In any of the above embodiments, the detector module 500 may include an electric shield 700. An exemplary electric shield 700 is shown in FIGS. 10A, 10B, and 10D. The electric shield 700 may be configured to shield at least a portion of the detector module 500 from electric fields. The electric shield 700 may be attached to the support 501. Preferably, the portion of the detector module 500 that is shielded by the electric shield 700 remains shielded even when an external disturbance that deforms the support 501 is applied. In particular, the electric shield 700 may beneficially protect sensitive circuitry surrounding the detection portion of the detector 531 from electric fields. The electric shield 700 is beneficial for shielding portions of the detector that are not used for detection and other circuitry. Such circuitry may be adversely affected by incident electrons and charged particles, and the electric shield 700 may reduce or avoid such effects.

[0172]

[0181] The detector 531 preferably includes a detector portion configured to detect the incident charged particle beam, and another portion of the detector 531 including circuitry for supporting the functionality of the detector portion, which may be referred to as a non-detection portion or circuit portion. The circuitry of the circuit portion may function to process a detection signal generated by the detector upon detection of a signal charged particle. The circuit portion may be present around the detection portion, e.g., may surround the detection portion. The detection portion is positioned in the path of the secondary beam to detect the signal charged particle. The detection portion is intended to be exposed to the secondary beam. The circuitry is for supporting the detector portion and is positioned in close proximity to the detector portion, preferably as close as possible, but is sensitive to charged particle exposure. The electric shield 700 is preferably configured to shield other portions, e.g., the circuit portion.

[0173]

[0182] The electric shield 700 may include a planar portion 701. The planar portion 701 may be a flat portion of the electric shield 700. Preferably, when the electric shield 700 is in place, e.g., attached to the support 501, the planar portion 701 of the electric shield 700 is parallel to the feedthrough 522. This is beneficial in protecting portions of the detector module 500 that may be negatively affected by incidental charged particles. The planar portion 701 may form the portion of the electric shield 700 closest to the detector 531. The planar portion 701 may be substantially perpendicular to the incidental charged particle beam path 535.

[0174]

[0183] Preferably, an aperture 702 is defined in the planar portion 701 of the electric shield 700 for the incidental charged particle beam path 535 to pass through. The aperture 702 is shown in FIG. 10B . The aperture 702 allows charged particles from the incidental charged particle beam to reach the detector 531 while restricting scattered charged particles from reaching other components of the detector module 500, such as the circuit portion. Preferably, the aperture 702 has a symmetrical shape to reduce asymmetric effects on the detector 531. In this manner, the shielding effect of the electric shield is substantially symmetrical with respect to the detector 531 to reduce asymmetric loading on the detector that may occur due to interaction of the signal charged particles with the detector 531. The aperture 702 can be any shape. Preferably, the aperture 702 is substantially circular, hexagonal, or square. The aperture 702 can be a slot. The aperture 702 can be substantially similar in shape to the detecting portion of the detector 531. Additionally or alternatively, the detection portion may have a symmetrical shape, such that the shape defined by the non-detection portion surrounds the circuit portion. Thus, the aperture may correspond to the shape of the detection portion and / or the non-detection portion. The aperture may define at most an area corresponding to the detection portion, and may be smaller to ensure shielding of the circuit portion from signal particles.

[0175]

[0184] The electric shield 700 may include a body portion 703 that includes a cylindrical portion 704. The body portion 703 may include a planar portion 701. The electric shield 700 may include an attachment 705 for connecting the body portion 703 to the support 501. More specifically, the electric shield 700 may include an attachment 705 for connecting the cylindrical portion 704 to the support 501. The attachments 705 may be one or multiple (e.g., two, three, or four or more). Preferably, the attachments 705 of the electric shield 700 are positioned symmetrically around the cylindrical portion 704 with respect to the incident charged particle beam path 535. For example, the electric shield 700 may have three attachments 705 positioned equidistant from one another and surrounding the cylindrical portion 704. However, there may be only one or two attachments, or there may be four or more attachments. Due to the positioning of the attachment, the attachment 705 and / or the electric shield 700 may be symmetric, eg, rotationally symmetric, with respect to the incident charged particle beam path 705 .

[0176]

[0185] In any of the above embodiments, the detector module 500 may include a magnetic shield 730. Exemplary magnetic shields 730 are shown in FIGS. 10A, 10C, and 10D. The magnetic shield 730 may be configured to shield at least a portion of the detector module 500 from magnetic fields. The magnetic shield 730 may be attached to the support 501. Preferably, the portion of the support 501 that is shielded by the magnetic shield 730 remains even when an external disturbance that deforms the support 501 is applied. Preferably, the magnetic shield 730 is positioned as close as possible to the detector 531 to maximize the shielding provided, so that the trajectory of the incident charged particle beam is as unaffected as possible by external magnetic fields.

[0177]

[0186] The magnetic shield 730 may include a cylindrical body 731. Preferably, when the magnetic shield 730 is positioned in the detector module 500, the cylindrical body 731 has an axis that is substantially parallel to the incident charged particle beam path 535.

[0178]

[0187] The magnetic shield 730 may be any suitable material. Preferably, the magnetic shield may be HyMu 80® or an equivalent material.

[0179]

[0188] The magnetic shield 730 may include an attachment 732 for connecting the magnetic shield 730 to the support 501. More specifically, the magnetic shield 730 may include an attachment 732 for connecting the cylindrical body 731 to the support 501. Depending on the position of the attachment 732, the attachment 732 and / or the magnetic shield 730 may be symmetric, e.g., rotationally symmetric, with respect to the incident charged particle beam path 705. Preferably, the attachment 732 connects the magnetic shield 730 to the electric shield 700, which in turn is attached to the support 501. In other words, the connection of the magnetic shield 730 to the support 501 may be via the electric shield 700, or in another arrangement, the electric shield 700 may be via the magnetic shield 730. Both of these arrangements are examples where the magnetic shield and the electric shield are connected to the support at one or more of the same locations.

[0180]

[0189] For example, the magnetic shield 730 may have three attachments 732. The three attachments 732 may be positioned around the cylindrical body 731, and preferably the attachments 732 may be equidistant from one another. However, there may be only one attachment. The attachment 732 may be provided as a single attachment surrounding the cylindrical body 731. Alternatively, the magnetic shield 730 may include multiple attachments, for example, two, three, four, or more attachments. Preferably, the multiple attachments 732 are positioned around the cylindrical body 731 symmetrically with respect to the incident charged particle beam path 535.

[0181]

[0190] Preferably, the magnetic shield 730 is rotationally symmetric with respect to the incidental charged particle beam path 535. In other words, the magnetic shield can be rotated about the incidental charged particle beam path 535, and after a certain amount of rotation, the magnetic shield 730 will be the same. This is shown in Figure 10C, where the attachments are formed as three attachments equidistant from each other around the circumference of the cylindrical body 731.

[0182]

[0191] Preferably, the electric shield 700 and / or the magnetic shield 730 are connected to an outer portion of the support 501. Preferably, the electric shield 700 and / or the magnetic shield 730 are connected to an outer portion of the support 501, rather than to an inner portion of the support 501 where the device 331 / detector 531 may be attached. For example, the electric shield 700 and / or the magnetic shield 730 may be attached to an outer portion of the support 501, i.e., a portion of the support 501 that is not in direct contact, e.g., indirect contact, radially outward of the feedthrough 522 / ring 521. More specifically, the electric shield 700 and / or the magnetic shield 730 may be attached to the inner mounting portion 520 and / or the outer mounting portion 519. The electric shield 700 and / or the magnetic shield 730 may be connected to the support at a component that is radially inward of the elastic member 514, if the elastic member 514 is provided, for example, to the inner mounting portion 520. This is beneficial in reducing the effect that deformation of support 501 has on the position of electric shield 700 and / or magnetic shield 730 .

[0183]

[0192] Overall, the electric and / or magnetic shields are useful for avoiding variations in the incidental charged particle beam path 535, protecting components of the detector module 500, and helping to maintain the position of the detector 531 relative to the incidental charged particle beam path 535. Thus, for example, shielding of the detector circuitry is maintained while the support deforms to maintain the detector's position relative to the secondary beam. The electric and / or magnetic shields 700 and 730 may effectively form a conduit for charged particles to target the detector 531.

[0184]

[0193] In the various embodiments and examples described above, particular locations of parts of the detector module 500 are described. As described herein, it may be preferable for certain components of the detector module 500 to be positioned symmetrically about at least one plane and / or axis.

[0185]

[0194] Symmetry may exist in at least one, preferably several, individual aspects of the design, including the mechanical design, electrical connectivity, and / or conditioning system. The symmetry may be rotational symmetry. The symmetry may be mirror symmetry, e.g., symmetry in a plane. For example, symmetry may exist in a plane containing the incidental charged particle beam path 535, preferably a plane that is orthogonal to the plane that is coplanar with the detector. For example, symmetry may exist in a plane that is orthogonal to the incidental charged particle beam path 535, e.g., a plane that is parallel to plane 536.

[0186]

[0195] As mentioned above, the applied disturbances can affect the position of the detector 531 in the plane of the detector 531 (which may be parallel to the plane 536 in FIG. 4A ) or along the incidental charged particle beam path 535 (which may be orthogonal to the plane of the detector 531). The applied disturbances can affect the rotation of the detector 531 about the incidental charged particle beam path 535 and / or the tilt (or angle) of the detector 531 from the ideal detector plane (i.e., orthogonal to the beam path 535 or the initial calibration position of the beam path). Thus, symmetry of at least one component can be beneficial in reducing or preventing deformation of the support 501 that could result in such movement of the detector 531, e.g., translation, rotation, tilt, etc.

[0187]

[0196] Preferably, the detector 531 is designed with an assumed thermal center that coincides with the charged particle beam path 535. (Accordingly, the elastic member 514 is preferably designed to be radially in / outwardly compliant relative to the thermal center.) All other degrees of freedom, including tilt and rotation, are preferably constrained by design. This means that when (asymmetric) external forces are applied to components such as the feedthrough 522, the ring 521, the inner mounting support 520, etc., the resulting displacements are also limited.

[0188]

[0197] As previously described, it is beneficial to maintain the position of the detector 531 relative to the incidental charged particle beam path 535. As also described, disturbances applied during operation deform the support 501. In general, the detector module 500 can be configured such that disturbances of the support 501 are symmetrical with respect to the incidental charged particle beam path 535. This can be implemented in many different ways. For example, the use of the elastic member 514 described above, the positioning of the detector 531, the use of the thermal conditioning system 560, the feedthrough 522, the configuration of the support 501 and / or the electronics unit 690 can be positioned such that disturbances of the support are symmetrical with respect to the incidental charged particle beam path 535. In other words, deformations of the support 501 can be symmetrical with respect to the incidental charged particle beam path 535. That is, the position of the detector 531 can be maintained with respect to the incidental charged particle beam path 535.

[0189]

[0198] Furthermore, it should be noted that tools and devices in which such detector modules 500 may be used typically have volume constraints. A symmetrical design can improve or maximize integration density given such limited space. This can address the drawbacks of volume constraints that often limit design options. Providing symmetry to aspects of the detector module 500 as described is beneficial in balancing precise positioning toward the detector 531, efficient thermal conditioning, and optimized electrical connections.

[0190]

[0199] The detector 531 may be positioned in a central region of the feedthrough 522. The detector 531 and / or the feedthrough 522 may have mirror symmetry, i.e., symmetry in a plane. The detector 531 may be positioned in the feedthrough 522 such that the detector 531 and the feedthrough 522 are symmetrical in at least one plane that includes the incidental charged particle beam path 535. The detector 531 and / or the feedthrough 522 may be positioned substantially symmetrical in a plane that includes the incidental charged particle beam path 535, the plane being perpendicular to the feedthrough 522.

[0191]

[0200] Components connected to or part of feedthrough 522 may have mirror symmetry. For example, electrical connection 512 may be symmetrical in a plane (represented by line P1 in FIG. 9A) perpendicular to feedthrough 522. Electrical connection 512 may be symmetrical in a further plane (represented by line P2) perpendicular to the feedthrough and plane (P1).

[0192]

[0201] As described above, certain embodiments may include the elastic member 514, which may be a first type of elastic member 514A and / or a second type of elastic member 514B. The elastic member 514 may be symmetric, e.g., rotationally symmetric, with respect to the incidental charged particle beam path 535. The elastic member 514 may be substantially symmetric in a plane that includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522. The elastic member 514 may be symmetric in a plane parallel to the feedthrough 522. The elastic member 514 may be configured such that deformation of the support 501 is symmetric with respect to the incidental charged particle beam path 535 during operation of the detector 531.

[0193]

[0202] As described above, the detector module 500 may include a rigid body 511. The rigid body may be configured such that deformation of the support 501 during operation of the detector 531 is symmetrical with respect to the incident charged particle beam path 535. The rigid body 511 may be positioned to be symmetrical, e.g., rotationally symmetrical, with respect to the incident charged particle beam path 535. The rigid body 511 may be configured to be symmetrical in a plane parallel to the feedthrough 522. The rigid body 511 may also be symmetrical in a plane that includes the incident charged particle beam path 535, the plane being perpendicular to the feedthrough 522.

[0194]

[0203] As mentioned above, the rigid body may be at least a part of the thermal conditioning system 650. Because the thermal conditioning system 650 may include the rigid body 511, at least a part of the thermal conditioning system 650 may be symmetrically positioned. As described in relation to the rigid body 511, the thermal conditioning system 650 may be configured such that deformation of the support 501 during operation of the detector 531, e.g., due to thermal fluctuations, is symmetric with respect to the incident charged particle beam path 535.

[0195]

[0204] Certain components of the thermal conditioning system 650 may be positioned symmetrically (e.g., as shown in FIGS. 8A, 8B, and 9A). As discussed above, the thermal conditioning system may generate and propagate vibrations along the fluid conditioning path. The conditioning fluid may be an incompressible fluid (e.g., water) that is more likely to propagate vibrations. Providing the components of the thermal conditioning system 650 in symmetrical positions should mean that any strain induced by the thermal conditioning system 650 may be applied more symmetrically around the support than would be the case without this measure.

[0196]

[0205] The supply connection 651 and the return connection 652 may be positioned in a central region of the feedthrough 522. The supply connection 651 may be a single connection or multiple connections, i.e., two, three, or more than three connections. The return connection 652 may be a single connection or multiple connections, i.e., two, three, or more than four connections. The supply connection 651 and the return connection 652 may be positioned symmetrically with respect to the support 501. For example, at least one supply connection 561 and return connection 562 may be positioned opposite each other with respect to a plane containing the incidental charged particle beam path 535, which plane is perpendicular to the feedthrough 522. The supply connection 561 and the return connection 562 may be rotationally symmetric with respect to the incidental charged particle beam path 535.

[0197]

[0206] As described above, a channel 653 may be provided that may be at least partially defined by thermal conditioning system 650. Channel 653 may be positioned in a central region of feedthrough 522. Channel 653 may be provided in a region of feedthrough 522 opposite detector 531 attached to the other side of feedthrough 522.

[0198]

[0207] The shape of the channel 653 may be substantially symmetrical with respect to the incidental charged particle beam path 535. Specifically, the shape of the channel may be substantially rotationally symmetrical with respect to the incidental charged particle beam path 535, for example, as shown in FIG. 8A. In other words, it may be possible to rotate the channel about the incidental charged particle beam path 535, with the channel 535 appearing the same at least twice in a 360-degree rotation. The shape of the channel 653 may be substantially symmetrical with respect to a plane, for example, a plane that includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522, as shown in FIG. 8B. The plane of symmetry may lie substantially through the middle of the detector 531 and / or the feedthrough 522 and / or the support 501.

[0199]

[0208] The channel 653 may have a curved path, which may alternatively be referred to as a serpentine path and / or a convoluted path (i.e., a route). Preferably, the channel includes at least a portion that is sinusoidal. Preferably, the path is formed in an S-shape, as shown in FIG. 8A.

[0200]

[0209] 9A, the fluid supply duct 656 and the fluid return duct 657 may be symmetrical in a plane (represented by line P1) perpendicular to the feedthrough. The fluid supply duct 656 and the fluid return duct 657 may be symmetrical in a further plane (represented by line P2) perpendicular to the feedthrough and plane (P1). The fluid supply duct and the fluid return duct may be symmetrical in the same plane (or even the same plane) as the electrical connections 512 on the feedthrough 522, although these components may be symmetrical with respect to different planes.

[0201]

[0210] As described above, the detector module 500 may include an electronics unit 670. The electrical connections of the electronics unit 670 may be positioned symmetrically with respect to the incidental charged particle beam path 535. The electronics unit 670 may be positioned symmetrically with respect to a plane. For example, the plane includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522. The plane of symmetry may lie substantially through the middle of the detector 531 and / or the feedthrough 522 and / or the support 501. The electrical connections of the electronics unit 670 may be positioned symmetrically. The electrical connections on the support 501 may also be positioned symmetrically.

[0202]

[0211] As described above, the thermal conditioning system 670 may include a first fluid path (sometimes referred to as a first circuit) and a second fluid path (sometimes referred to as a second circuit). The first fluid path and the second fluid path may be arranged substantially in a plane. For example, the plane includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522. The plane may extend substantially through the middle of the detector 531 and / or the feedthrough 522 and / or the support 501. The electronics unit 670 may be arranged in substantially the same plane. The electronics unit 670 may be arranged within the second fluid path within the plane. For example, in a cross section through the plane, the electronics unit 670 may be at least partially surrounded by the second fluid path.

[0203]

[0212] At least a portion of the first flow path can be symmetrical within a plane. For example, the plane includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522. At least a portion of the second flow path can be substantially symmetrical within a plane. For example, the plane includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522. The first and second flow paths can also be symmetrical within the same plane.

[0204]

[0213] As described above, the detector 531 and / or the feedthrough 522 and / or the support 501 may be positioned within the detector module 500 such that the detector 531 and / or the feedthrough 522 and / or the support 501 are symmetrical with respect to the incidental charged particle beam path 525. The detector 531 and / or the feedthrough 522 and / or the support 501 may be rotationally symmetrical about the incidental charged particle beam path 535. The detector 531 and / or the feedthrough 522 and / or the support 501 may have reflection symmetry (i.e., mirror symmetry) in a plane, for example, a plane that includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522. This plane may lie substantially through the middle of the detector 531 and / or the feedthrough 522 and / or the support 501.

[0205]

[0214] The feedthrough 522 according to any of the above embodiments or examples includes an electrical connection 512 on a surface of the feedthrough 522. There may be one electrical connection or multiple electrical connections, e.g., two, three, or four or more. The shape of the electrical connection 512 may be symmetric. For example, the electrical connection 512 may be symmetric in a plane, e.g., in a plane that includes the incidental charged particle beam path 535 and is perpendicular to the feedthrough 522. For example, the electrical connection may have mirror symmetry with respect to a plane that passes through the middle of the feedthrough 522, as shown in FIGS. 8A and 8B. Additionally or alternatively, the electrical connection 512 may be rotationally symmetric with respect to, e.g., the incidental charged particle beam path 535, which is also shown in FIGS. 8A and 8B.

[0206]

[0215] Any of the above embodiments or examples may include an electric shield 700 and / or a magnetic shield 730. The electric shield 700 and / or the magnetic shield 730 may be provided with a shape that is symmetrical with respect to the incidental charged particle beam path 535. For example, the electric shield 700 and / or the magnetic shield 730 may be rotationally symmetrical with respect to the incidental charged particle beam path 535. The electric shield 700 and / or the magnetic shield 730 may be symmetrical with respect to a plane, i.e., have mirror symmetry, the plane containing the incidental charged particle beam path 535. The electric shield 700 and / or the magnetic shield 730 may be symmetrical with respect to a plane that is orthogonal to the incidental charged particle beam path 535, for example, a plane parallel to the plane 536 shown in FIG. 4A . The electric shield 700 and / or the magnetic shield 730 may also be symmetrical with respect to, for example, the same axis (such as the incidental charged particle beam path 535) and / or the same plane (e.g., a plane that contains and is orthogonal to the incidental charged particle beam path 535).

[0207]

[0216] In any of the above embodiments, the detector module 500 may be configured to reduce or minimize thermal resistance between components. This can be done by selecting materials to reduce variations in thermal expansion coefficients. At least two components of the detector module 500 may include one or more materials that reduce or minimize thermal resistance between the components. For example, the materials may be the same, or materials with substantially similar coefficients of thermal expansion (CTE) may be used for different components.

[0208]

[0217] For example, the feedthrough 522 may include a material that can reduce or minimize the thermal resistance between the detector (531 (or device 331)) and the feedthrough 522. For example, the feedthrough 522 may include a material (e.g., an insulator, ceramic, alumina, SiN, etc.) that has a coefficient of thermal expansion (CTE) that is substantially similar to that of the detector 531 (or device 331) (e.g., the CTE of the feedthrough 522 may be similar or identical to that of the detector 531 (or device 331)). Matching the CTE or selecting materials with similar CTEs for the feedthrough 522 and the detector 531 may be particularly beneficial in reducing or minimizing stresses and strains in the detector 521 and / or feedthrough 522 that could otherwise damage the detector 531. This is advantageous in maintaining the quality of the inspection system after high-temperature processes (e.g., bake cycles). Of course, other components of the detector module 500 may also have substantially similar thermal expansion coefficients.

[0209]

[0218] More generally, reducing or minimizing CTE (coefficient of thermal expansion) mismatch is beneficial in reducing or minimizing the effects of disturbances (e.g., due to thermal loads generated during normal use and / or failure of the thermal conditioning system and / or bake-out procedures). This allows for easier vacuum generation within the vacuum chamber. Matching the thermal expansion coefficients of the components of the detector module 500 can be beneficial in maintaining the position of the detector 531 relative to the incident charged particle beam path 535, as unaddressed thermal distortion can lead to inaccurate positioning. In some embodiments, the PCB can include a material that can reduce or minimize thermal resistance between the device and the PCB. For example, the PCB can include a material (e.g., insulator, ceramic, alumina, SiN, etc.) with a CTE substantially similar to that of the device (e.g., the CTE of the PCB 322 can be similar or the same as that of the device 331), advantageously reducing distortion in the PCB and device, thereby maintaining the quality of the inspection system after high-temperature processes (e.g., bake cycles).

[0210]

[0219] For different applications, the feedthrough 522 (e.g., PCB) may have different shapes (e.g., circular, hexagonal, rectangular, etc.) when viewed in the y-direction to enhance the interface between the atmospheric environment and the vacuum chamber environment.

[0211]

[0220] In one embodiment, a method for detecting an incidental charged particle beam (e.g., in a charged particle beam inspection tool) is provided. The method includes providing a detector module, which may be the detector module 500 described in any of the above-described embodiments / variations. The detector module 500 includes a detector 531 configured to be alignable with an incidental charged particle beam path 535. The detector module 500 also includes a support 501 for defining at least a portion of a wall of a vacuum chamber. The support 501 may include a feedthrough 522 to which the detector 531 is attached, and the detector 531 is electrically connected through the feedthrough 522. As described above, an applied disturbance may cause the support 501 to deform. The detector module 500 is configured such that a position of the detector 531 is maintained relative to the incidental charged particle beam path 535 during operation of the detector 531 in the presence of disturbances to the detector 531 and / or the support 501. The method further includes providing a vacuum environment around the detector 535 and providing the incidental charged particle beam for detection by the detector 531.

[0212]

[0221] In one embodiment, a method for detecting an incidental charged particle beam in a charged particle beam inspection tool is provided. The method includes operating a detector 531, for example as described in any of the above embodiments. The method includes maintaining a position of the detector 531 relative to the incidental charged particle beam path 535 when a disturbance is applied to the detector 531 and / or the support 501.

[0213]

[0222] The detector module 500 may include a resilient member 514 (e.g., as described in any of the above embodiments) surrounding the feedthrough 522. The resilient member 514 may be configured to move radially inward and outward in a plane perpendicular to the incident charged particle beam path 535.

[0214]

[0223] The detector module 500 may include a thermal conditioning system 650. The method may include transferring heat from the support 501. Once the heat is transferred from the support 501, the method further includes transferring heat from the detector 531.

[0215]

[0224] As mentioned above, the detector 531 and / or the feedthrough 522 and / or the support 501 may be positioned within the detector module 500 to be symmetrical with respect to a plane parallel to the incident charged particle beam path 535 and / or the detector 531 and / or the feedthrough 522. The detector 531 and / or the feedthrough 522 and / or the support 501 may be symmetrical as described in any of the variations above.

[0216]

[0225] In one embodiment, a method for detecting an incidental charged particle beam (e.g., in a charged particle beam inspection tool) is provided. The method includes providing a detector module, which may be the detector module 500 described in any of the above-described embodiments / variations. The detector module 500 includes a detector 531 configured to operate within a vacuum chamber. The detector 531 may be configured to be alignable with an incidental charged particle beam path 535. The detector module 500 may include a support 501 for defining at least a portion of a wall of the vacuum chamber, the support 501 including a feedthrough 522 to which the detector 531 is attached. The detector may be electrically connected through the feedthrough 522. The detector module 500 may include a thermal conditioning system 650 including a support thermal conditioning section configured to thermally condition the support 501 and a further thermal conditioning section configured to thermally condition another portion of the detector module 500. The detector module 500 also includes a separable portion including other portions of the detector module 500 and the further thermal conditioning section, the separable portion being configured to be removable from the detector module 500. The method may further include providing a fluid to the support thermal conditioning section and the further thermal conditioning section, providing a vacuum environment around the detector 531, and / or providing an incidental charged particle beam for detection by the detector 531.

[0217]

[0226] In one embodiment, a method for removing a separable portion from a detector module can be provided. The detector module 500 can include a thermal conditioning system 650, which can include a separable portion as described above. The method can include separating the further thermal conditioning section from the support thermal conditioning section and removing other portions from the detector module 500.

[0218]

[0227] In one embodiment, a method for detecting an incidental charged particle beam (e.g., in a charged particle beam inspection tool) is provided. The method may include providing a detector module, which may be the detector module 500 described in any of the above-described embodiments / variations. The detector module 500 may include a detector 531 configured to operate within a vacuum chamber. The detector 531 may be configured to be alignable with an incidental charged particle beam path 535. The detector module 500 may include a support 501 for defining at least a portion of a wall of the vacuum chamber, the support 501 may include a feedthrough 522 to which the detector 531 is attached. The detector 531 may be electrically connected through the feedthrough 522. The detector module 500 may also include an electric shield 700 configured to shield at least a portion of the support 501 from an electric field, the electric shield 700 being attached to the support 501 such that the portion of the detector module 500 remains shielded by the electric shield 700 during operation in the presence of a disturbance that deforms the support 501. The method may further include providing a vacuum environment around the detector 531 and providing an incident charged particle beam for detection by the detector 531. The method may include maintaining the portion of the detector module 500 shielded by an electric shield during operation.

[0219]

[0228] In one embodiment, a method is provided for detecting an incident charged particle beam using a detector module according to any of the above embodiments / variants.

[0220]

[0229] Evaluation tools according to embodiments of the present invention may perform qualitative evaluations of a sample (e.g., pass / fail), quantitative measurements of a sample (e.g., feature size), or generate an image map of the sample. Examples of evaluation tools are inspection tools (e.g., to identify defects), review tools (e.g., to classify defects), and metrology tools or tools capable of performing any combination of evaluation functionality associated with an inspection tool, review tool, or metrology tool (e.g., metrology inspection tool). The electron optical column 40 may be a component of an evaluation tool, such as an inspection tool or metrology inspection tool, or part of an electron beam lithography tool. Any reference to a tool herein is intended to encompass a device, apparatus, or system, and a tool includes various components that may or may not be collocated and may be located in different spaces, particularly, for example, data processing elements.

[0221]

[0230] Reference to a component or system of components or elements controllable to manipulate a charged particle beam in a particular manner includes configuring a controller or control system or control unit to control the component to manipulate the charged particle beam in the described manner, and optionally using other controllers or devices (e.g., voltage supplies and / or current supplies) to control the component to manipulate the charged particle beam in this manner. For example, a voltage supply, under the control of a controller or control system or control unit, may be electrically connected to and apply an electrical potential to one or more components, including, for example, a control lens array, an objective lens array 241, a condenser lens 210, a corrector, a collimator element array, and a scan deflector array, in a non-limiting list. An actuatable component, such as a stage, may be actuated using one or more controllers, control systems, or control units that control the actuation of the component, and thus be controllable to move relative to another component, such as a beam path.

[0222]

[0231] References to top and bottom, above and below, up and down should be understood as referring to directions parallel to the (usually, but not necessarily, perpendicular) up-beam and down-beam directions of the electron beam or multi-beam impinging on the sample. References to up-beam and down-beam are therefore intended to refer to directions relative to the beam path, regardless of the prevailing gravitational field. Up-beam is towards the source and down-beam is towards the sample.

[0223]

[0232] It will be understood that the embodiments of the present disclosure are not limited to the exact constructions described above and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof.

[0224]

[0233] The following clauses define preferred combinations of features. Applicant reserves the right to pursue protection for these combinations of features and / or any other subject matter contained in this application as filed. These clauses are not claims of this application contained in a separate section under the heading "Claims."

[0225]

[0234] Clause 1: A system for sealing a vacuum system configured to provide an atmospheric environment and a vacuum chamber environment, the system comprising: a printed circuit board (PCB) including a first side for exposure to the atmospheric environment and a second side for exposure to the vacuum chamber environment and covering an aperture in the vacuum chamber environment, the second side being opposite the first side; a rigid body on the first side of the PCB; and a device connected to the second side of the PCB and positioned on a portion of the PCB covering the aperture, the PCB configured to provide an interface between the device and the rigid body.

[0226]

[0235] Clause 2: The system of clause 1, wherein the PCB comprises SiN.

[0227]

[0236] Clause 3: The system of clause 1, wherein the PCB comprises alumina.

[0228]

[0237] Clause 4: The system of any one of clauses 1 to 3, wherein the PCB includes multiple layers.

[0229]

[0238] Clause 5: The system of clause 4, wherein each layer includes at least one of a via or a trace.

[0230]

[0239] Clause 6: The system of clause 5, wherein the via comprises a plurality of vias.

[0231]

[0240] Clause 7: The system of any one of clauses 5-6, wherein the vias do not extend through the entire length of the PCB.

[0232]

[0241] Clause 8: The system of any one of clauses 5 to 7, wherein the trace comprises a plurality of traces.

[0233]

[0242] Clause 9: The system of any one of clauses 5 to 8, wherein the traces are configured to route high-speed signals.

[0234]

[0243] Clause 10: The system of any one of clauses 1 to 9, wherein the PCB includes a material configured to reduce thermal resistance between the device and the PCB.

[0235]

[0244] Clause 11: The system of any one of clauses 1 to 10, wherein the PCB comprises a material having a coefficient of thermal expansion substantially similar to the coefficient of thermal expansion of the device.

[0236]

[0245] Clause 12: A system described in any one of clauses 1 to 11, wherein the interface is configured to provide a thermal connection between the rigid body and the device.

[0237]

[0246] Clause 13: A system described in any one of clauses 1 to 12, wherein the rigid body is further configured to extend over the material forming the aperture.

[0238]

[0247] Clause 14: The system of any one of clauses 1 to 13, wherein the rigid body is further configured to provide mechanical support to the PCB.

[0239]

[0248] Clause 15: A system according to any one of clauses 1 to 14, wherein the PCB provides an airtight seal against the vacuum chamber environment.

[0240]

[0249] Clause 16: The system of clause 15, wherein the rigid body is further configured to reinforce the hermetic seal provided by the PCB.

[0241]

[0250] Clause 17: The system of any one of clauses 1 to 16, wherein the rigid body comprises a plurality of rigid bodies.

[0242]

[0251] Clause 18: The system of any one of clauses 1 to 17, wherein the rigid body includes a cooling system.

[0243]

[0252] Clause 19: A system described in any one of clauses 1 to 18, further comprising a flexible element for exposure in a vacuum chamber environment.

[0244]

[0253] Clause 20: The system of clause 19, wherein the flexible element comprises a plurality of flexible elements.

[0245]

[0254] Clause 21: A system described in any one of clauses 19 to 20, wherein the flexible element is configured to provide mechanical support to the PCB.

[0246]

[0255] Clause 22: A system described in any one of clauses 19 to 21, wherein the flexible element is configured to reinforce the hermetic seal provided by the PCB.

[0247]

[0256] Clause 23: The system of any one of clauses 1 to 22, further comprising a material that forms an aperture, the material surrounding the aperture and comprising a circular shape.

[0248]

[0257] Clause 24: A system described in any one of clauses 1 to 23, wherein the device is directly connected to the second side of the PCB.

[0249]

[0258] Clause 25: The system of any one of clauses 1 to 24, wherein the device includes multiple devices.

[0250]

[0259] Clause 26: A system according to any one of clauses 1 to 25, wherein the device includes a detector.

[0251]

[0260] Clause 27: A system described in any one of clauses 1 to 26, wherein the device is configured to operate within a vacuum chamber environment.

[0252]

[0261] Clause 28: A system described in any one of clauses 1 to 27, further comprising a material that forms an aperture and surrounds the aperture, and wherein the PCB further comprises a sealing layer on one side of the PCB, the sealing layer being positioned between the material and a second side of the PCB.

[0253]

[0262] Clause 29: The system of clause 28, wherein the sealing layer comprises a plurality of sealing layers.

[0254]

[0263] Clause 30: The system of any one of clauses 28-29, wherein the sealing layer comprises solder.

[0255]

[0264] Clause 31: A system according to any one of clauses 1 to 30, comprising an extreme ultraviolet inspection system.

[0256]

[0265] Clause 32: A system according to any one of clauses 1 to 30, comprising a deep ultraviolet inspection system.

[0257]

[0266] Clause 33: The system of any one of clauses 1 to 32, wherein covering the aperture includes filling the aperture.

[0258]

[0267] Clause 34: A method for sealing a vacuum system configured to provide an atmospheric environment and a vacuum chamber environment, the method comprising: providing an interface between a device and a rigid body using a printed circuit board (PCB), the PCB having a first side for exposure to the atmospheric environment and a second side for exposure to the vacuum chamber environment and covering an aperture in the vacuum chamber environment, the second side opposite the first side, the rigid body being on the first side of the PCB, the device being connected to the second side of the PCB and positioned in a portion of the PCB covering the aperture; and operating the device in the vacuum system.

[0259]

[0268] Clause 35: The method of clause 34, wherein the PCB comprises SiN.

[0260]

[0269] Clause 36: The method of clause 34, wherein the PCB comprises alumina.

[0261]

[0270] Clause 37: The method of any one of clauses 34 to 36, wherein the PCB comprises multiple layers.

[0262]

[0271] Clause 38: The method of clause 37, wherein each layer includes at least one of a via or a trace.

[0263]

[0272] Clause 39: The method of clause 38, wherein the via comprises a plurality of vias.

[0264]

[0273] Clause 40: The method of any one of clauses 38-39, wherein the vias do not extend through the entire length of the PCB.

[0265]

[0274] Clause 41: The method of any one of clauses 38 to 40, wherein the trace comprises a plurality of traces.

[0266]

[0275] Clause 42: The method of any one of clauses 38 to 41, wherein the traces are configured to route high-speed signals.

[0267]

[0276] Clause 43: The method of any one of clauses 34 to 42, wherein the PCB includes a material configured to reduce thermal resistance between the device and the PCB.

[0268]

[0277] Clause 44: The method of any one of clauses 34 to 43, wherein the PCB comprises a material having a coefficient of thermal expansion substantially similar to the coefficient of thermal expansion of the device.

[0269]

[0278] Clause 45: The method of any one of clauses 34 to 44, wherein the interface is configured to provide a thermal connection between the rigid body and the device.

[0270]

[0279] Clause 46: The method of any one of clauses 34 to 45, wherein the rigid body is further configured to extend over the material that forms the aperture.

[0271]

[0280] Clause 47: The method of any one of clauses 34 to 46, wherein the rigid body is further configured to provide mechanical support to the PCB.

[0272]

[0281] Clause 48: The method of any one of clauses 34 to 47, wherein the PCB provides an airtight seal to the vacuum chamber environment.

[0273]

[0282] Clause 49: The method of clause 48, wherein the rigid body is further configured to reinforce the hermetic seal provided by the PCB.

[0274]

[0283] Clause 50: The method of any one of clauses 34 to 49, wherein the rigid body comprises a plurality of rigid bodies.

[0275]

[0284] Clause 51: The method of any one of clauses 34 to 50, wherein the rigid body includes a cooling system.

[0276]

[0285] Clause 52: The method of any one of clauses 34 to 51, further comprising a flexible element for exposure in a vacuum chamber environment.

[0277]

[0286] Clause 53: The method of clause 52, wherein the flexible element comprises a plurality of flexible elements.

[0278]

[0287] Clause 54: The method of any one of clauses 52 to 53, wherein the flexible element is configured to provide mechanical support to the PCB.

[0279]

[0288] Clause 55: The method of any one of clauses 53 to 55, wherein the flexible element is configured to reinforce the hermetic seal provided by the PCB.

[0280]

[0289] Clause 56: The method of any one of clauses 34 to 55, further comprising a material that forms the aperture, the material surrounding the aperture and comprising a circular shape.

[0281]

[0290] Clause 57: The method of any one of clauses 34 to 56, wherein the device is directly connected to the second side of the PCB.

[0282]

[0291] Clause 58: The method of any one of clauses 34 to 57, wherein the device comprises a plurality of devices.

[0283]

[0292] Clause 59: The method of any one of clauses 34 to 58, wherein the device comprises a detector.

[0284]

[0293] Clause 60: The method of any one of clauses 34 to 59, further comprising a material that forms the aperture and surrounds the aperture, and the PCB further comprises a sealing layer on one side of the PCB, the sealing layer being positioned between the material and a second side of the PCB.

[0285]

[0294] Clause 61: The method of clause 60, wherein the sealing layer comprises a plurality of sealing layers.

[0286]

[0295] Clause 62: The method of any one of clauses 60-61, wherein the sealing layer comprises solder.

[0287]

[0296] Clause 63: The method of any one of clauses 34 to 62, wherein covering the aperture comprises filling the aperture.

[0288]

[0297] The following further clauses define further preferred combinations of features. The applicant reserves the right to seek protection for combinations of these features and / or for any other subject matter contained in this application at the time of filing.

[0289]

[0298] Further clause 1. A detector module for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool, comprising: a detector configured to operate within the vacuum chamber and configured to be alignable with an incidental charged particle beam path; and a support for defining at least a portion of the wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough, and an applied disturbance causing the support to deform, the detector module configured such that in the presence of disturbances to the detector and / or the support, the position of the detector is maintained relative to the incidental charged particle beam path during operation of the detector.

[0290]

[0299] Further clause 2. A detector module according to further clause 1, configured such that disturbances of the support are symmetrical with respect to the incident charged particle beam path.

[0291]

[0300] Further clause 3. A detector module according to any of further clauses 1 or 2, wherein the detector module partially constitutes a wall of a vacuum chamber for providing a vacuum environment, the detector being positioned within the vacuum chamber.

[0292]

[0301] Further clause 4. A detector module as described in any preceding further clause, wherein the feedthrough includes a first side for exposure to an atmospheric environment and a second side for exposure to a vacuum chamber, the second side being opposite the first side and for covering an aperture of the vacuum chamber, and the detector is positioned on the second side of the feedthrough that covers the aperture.

[0293]

[0302] Further clause 5. The detector module of any preceding further clause, wherein the detector is positioned in a central region of the feedthrough.

[0294]

[0303] Further clause 6. A detector module according to any preceding further clause, wherein the detector is positioned substantially symmetrically in a plane, the plane containing the incident charged particle beam path and perpendicular to the feedthrough.

[0295]

[0304] Further clause 7. A detector module according to any preceding further clause, further comprising an elastic member surrounding the feedthrough, the elastic member configured to move in radially inward and outward directions in a plane perpendicular to the incident charged particle beam path.

[0296]

[0305] Further clause 8. A detector module according to further clause 7, wherein the resilient member is configured such that during operation of the detector deformation of the support due to external disturbances is symmetrical with respect to the incident charged particle beam path.

[0297]

[0306] Further clause 9. A detector module according to any one of further clauses 7 or 8, wherein circumferential movement of the resilient member is limited.

[0298]

[0307] Further clause 10. A detector module according to any one of further clauses 7 to 9, wherein the elastic member is ring-shaped.

[0299]

[0308] Further clause 11. A detector module according to any one of further clauses 7 to 10, wherein the elastic member is formed in a single piece.

[0300]

[0309] Further clause 12. A detector module according to any one of further clauses 7 to 11, wherein the elastic member is formed of two or more bodies.

[0301]

[0310] Further clause 13. A detector module according to any one of further clauses 7 to 12, wherein the resilient member comprises a plurality of resilient members, the plurality of resilient members being positioned around the feedthrough in a rotationally symmetrical arrangement.

[0302]

[0311] Further clause 14. A detector module according to any one of further clauses 7 to 13, wherein one of the support or the elastic member includes a protrusion and the other of the support or the elastic member includes a recess configured to mate with the protrusion and prevent relative rotation between the support and the elastic member around the incident charged particle beam path.

[0303]

[0312] Further clause 15. A detector module according to any one of further clauses 7 to 14, wherein the elastic member is rotationally symmetric with respect to the incident charged particle beam path.

[0304]

[0313] Further Clause 16. A detector module according to any preceding further clause, further comprising a rigid body.

[0305]

[0314] Further clause 17. The detector module of further clause 16, wherein the rigid body is on a first side of the feedthrough for exposure to an atmospheric environment.

[0306]

[0315] Further clause 18. A detector module according to any of further clauses 16 or 17, wherein the rigid body is configured such that during operation of the detector deformation of the support is symmetrical with respect to the incident charged particle beam path.

[0307]

[0316] Further clause 19. A detector module according to any one of further clauses 16 to 18, wherein the rigid body is at least part of a thermal conditioning system configured to transfer heat from the support.

[0308]

[0317] Further clause 20. A detector module according to further clause 19, wherein the thermal conditioning system comprises at least one supply connection to which fluid is provided during use and at least one return connection to which fluid is returned during use.

[0309]

[0318] Further clause 21. A detector module according to further clause 20, wherein the at least one supply connection and the at least one return connection are positioned in a central region of the feedthrough.

[0310]

[0319] Further clause 22. A detector module according to any of further clauses 20 or 21, wherein the at least one supply connection and the at least one return connection are positioned symmetrically relative to the support.

[0311]

[0320] Further clause 23. A detector module according to any one of further clauses 19 to 22, wherein the thermal conditioning system defines at least a portion of the channel, the thermal conditioning system being configured to provide a conditioning fluid through the channel to transfer heat from the feedthrough.

[0312]

[0321] Further clause 24. A detector module according to further clause 23, wherein the channel is positioned in a central region of the feedthrough opposite a detector attached to the other side of the feedthrough.

[0313]

[0322] Further clause 25. A detector module according to any one of further clauses 23 or 24, wherein the shape of the channel is substantially symmetrical with respect to the incident charged particle beam path.

[0314]

[0323] Further clause 26. A detector module according to any one of further clauses 23 to 25, wherein the shape of the channel is substantially symmetrical about a plane, the plane containing the incident charged particle beam path and perpendicular to the feedthrough.

[0315]

[0324] Further clause 27. A detector module according to any one of further clauses 23 to 25, wherein the channel has a curved path, preferably including at least a portion which is sinusoidal, preferably the path is S-shaped.

[0316]

[0325] Further Clause 28. A detector module according to any preceding further clause, further comprising an electronics unit including electronics configured to be in signal communication with the detector for controlling the detector and receiving data from the detector, wherein at least the electronics unit includes a connection to the support.

[0317]

[0326] Further clause 29. A detector module according to further clause 28, wherein the electronics unit is spaced apart from the support and / or the electrical connections are positioned symmetrically with respect to the incident charged particle beam path.

[0318]

[0327] Further clause 30. A detector module according to any one of further clauses 19 to 27, further comprising an electronics unit including electronics configured to be in signal communication with the detector for controlling the detector and receiving data from the detector, the electronics unit including a connection to the support, and the thermal conditioning system configured to thermally condition from the electronics unit.

[0319]

[0328] Further clause 31. A detector module according to further clause 30, wherein the electronics unit is spaced apart from the support and / or the electrical connections are positioned symmetrically with respect to the incident charged particle beam path.

[0320]

[0329] Further clause 32. A detector module according to any one of further clauses 19 to 29, wherein the thermal conditioning system comprises a support thermal conditioning system configured to transfer heat from the support and a further thermal conditioning system configured to transfer heat from another part of the detector module, and the detector module further comprises a detachable part comprising the other part and the further thermal conditioning system, and the detachable part is configured to be removable from the detector module.

[0321]

[0330] Further clause 33. A detector module for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool, the detector being configured to operate within the vacuum chamber and configured to be alignable with an incident charged particle beam path, the detector module comprising: a support for defining at least a portion of the wall of the vacuum chamber, the support including a feedthrough to which the detector is attached and the detector is electrically connected through the feedthrough, a thermal conditioning system including a support thermal conditioning section configured to thermally condition the support and a further thermal conditioning section configured to thermally condition another portion of the detector module, and a detachable part including the other portion and the further thermal conditioning section, the detachable part being configured to be removable from the detector module.

[0322]

[0331] Further clause 34. A detector module according to either of further clauses 32 or 33, wherein another part is an electronics unit configured to be in signal communication with the detector for controlling the detector and receiving data from the detector, the electronics unit including a connection to a support.

[0323]

[0332] Further clause 35. A detector module according to further clause 34, wherein the electronics unit is spaced from the support and / or the electrical connections are positioned symmetrically with respect to the incident charged particle beam path.

[0324]

[0333] Further clause 36. A detector module according to any one of further clauses 32 to 35, wherein the support thermal conditioning section comprises a first fluid path comprising a fluid supply duct and a fluid return duct, and the further thermal conditioning section comprises a second fluid path comprising at least one duct.

[0325]

[0334] Further clause 37. A detector module according to further clause 36, wherein the fluid supply duct and / or the fluid return duct are flexible.

[0326]

[0335] Further clause 38. A detector module according to either of further clauses 36 or 37, wherein the first fluid path and the second fluid path are arranged substantially in a plane, the plane including the incident charged particle beam path and being perpendicular to the feedthrough.

[0327]

[0336] Further clause 39. A detector module according to further clause 38, wherein the electronics unit is provided in the second fluid path in the plane.

[0328]

[0337] Further clause 40. A detector module according to any one of further clauses 36 to 39, wherein the first fluid path and the second fluid path are substantially symmetrical about a plane, the plane including the incidental charged particle beam path and perpendicular to the feedthrough.

[0329]

[0338] Further Clause 41. A detector module according to any one of further clauses 36 to 40, wherein the first fluid path and the second fluid path are in fluid communication.

[0330]

[0339] Further Clause 42. A detector module according to any one of further clauses 36 to 41, further comprising a valve between the first fluid path and the second fluid path that can be opened or closed.

[0331]

[0340] Further clause 43. A detector module according to any preceding further clause, wherein the detector and / or feedthrough and / or support are positioned within the detector module so as to be symmetrical with respect to a plane parallel to the incident charged particle beam path and / or the detector and / or feedthrough.

[0332]

[0341] Further clause 44. A detector module according to any preceding further clause, wherein the feedthrough comprises at least one electrical connection on a surface of the feedthrough, the shape of the at least one electrical connection being symmetrical in a plane, the plane including the incident charged particle beam path and perpendicular to the feedthrough.

[0333]

[0342] Further Clause 45. The detector module of any preceding further clause, further comprising a magnetic shield configured to shield at least a portion of the detector module from a magnetic field, the magnetic shield being attached to the support.

[0334]

[0343] Further Clause 46. A detector module according to further Clause 45, further comprising an electric shield configured to shield at least a portion of the detector module from the electric field, the electric shield being attached to the support.

[0335]

[0344] Further clause 47. A detector module according to any one of further clauses 1 to 44, further comprising an electric shield configured to shield at least a portion of the detector module from an electric field, the electric shield being attached to the support.

[0336]

[0345] Further clause 48. A detector module for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool, the detector configured to operate within the vacuum chamber and configured to be alignable with an incident charged particle beam path; a support for defining at least a portion of the wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough; and an electric shield configured to shield at least a portion of the detector module from electric fields, the electric shield being attached to the support such that during operation, a portion of the detector module remains shielded by the electric shield under the application of a disturbance that deforms the support.

[0337]

[0346] Further clause 49. A detector module according to either of further clauses 47 or 48, wherein the detector comprises a detection portion configured to detect the incident charged particle beam and another portion of the detector, and the electric shield is configured to shield the other portion.

[0338]

[0347] Further clause 50. A detector module according to any one of further clauses 47 to 49, wherein the electric shield comprises a planar portion parallel to the feedthrough, and preferably an aperture is defined in the planar portion for the passage of the incidental charged particle beam path.

[0339]

[0348] Further clause 51. A detector module according to any one of further clauses 50, wherein the electrical shield comprises a body including a cylindrical portion and a planar portion, and at least one attachment for connecting the body to a support.

[0340]

[0349] Further clause 52. A detector module according to further clause 51, wherein the electric shield has three attachments positioned symmetrically around the cylindrical portion with respect to the incident charged particle beam path.

[0341]

[0350] Further clause 53. A detector module according to any one of further clauses 47 to 52, wherein the electric shield is rotationally symmetric with respect to the incident charged particle beam path.

[0342]

[0351] Further Clause 54. A detector module according to any one of further clauses 47 to 53, further comprising a magnetic shield configured to shield at least a portion of the detector module from magnetic fields.

[0343]

[0352] Further clause 55. A detector module according to further clause 54, wherein at least a portion of the magnetic shield is positioned within the electric shield.

[0344]

[0353] Further clause 56. A detector module according to any one of further clauses 54 or 55, wherein at least a portion of the electrical shield is positioned between the magnetic shield and the feedthrough.

[0345]

[0354] Further clause 57. A detector module according to any one of further clauses 54 to 56, wherein the magnetic shield comprises a cylindrical body, preferably the cylindrical body having an axis substantially parallel to the incident charged particle beam path.

[0346]

[0355] Further clause 58. A detector module according to further clause 57, wherein the magnetic shield comprises at least one attachment for connecting the cylindrical body to the support, preferably there are a plurality of attachments positioned symmetrically around the cylindrical body with respect to the incident charged particle beam path, preferably there are three attachments.

[0347]

[0356] Further clause 59. A detector module according to any one of further clauses 54 to 58, wherein the magnetic shield is rotationally symmetric with respect to the incident charged particle beam path.

[0348]

[0357] Further clause 60. A detector module according to any preceding further clause, wherein the feedthrough is a printed circuit board (PCB).

[0349]

[0358] Further clause 61. A method of detecting an incidental charged particle beam in a charged particle beam inspection tool, the method comprising: a) providing a detector module, the detector module comprising: a detector configured to be alignable with the incidental charged particle beam path; and a support for defining at least a portion of a wall of a vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough, and an applied disturbance causing the support to deform, the detector module configured such that in the presence of disturbances to the detector and / or the support, the position of the detector is maintained relative to the incidental charged particle beam path during operation of the detector; b) providing a vacuum environment around the detector; and c) providing the incidental charged particle beam for detection by the detector.

[0350]

[0359] Further clause 62. A method according to further clause 61, wherein the detector module includes a resilient member surrounding the feedthrough, the resilient member being configured to move in radially inward and outward directions in a plane perpendicular to the incident charged particle beam path.

[0351]

[0360] Further clause 63. A method according to any of further clauses 61 or 62, wherein the detector module further comprises a thermal conditioning system, and the method comprises transferring heat from the support.

[0352]

[0361] Further clause 64. A method according to any one of further clauses 61 to 63, wherein the detector and / or feedthrough and / or support are positioned within the detector module so as to be symmetrical with respect to a plane parallel to the incident charged particle beam path and / or detector and / or feedthrough.

[0353]

[0362] Further Clause 65. A method for detecting an incidental charged particle beam in a charged particle beam inspection tool, the method comprising: a) providing a detector module, the detector module comprising: a detector configured to operate in a vacuum chamber, the detector configured to be alignable with an incidental charged particle beam path; a support for defining at least a portion of a wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough; a thermal conditioning system including a support thermal conditioning section configured to thermally condition the support and a further thermal conditioning section configured to thermally condition another portion of the detector module; and a separable part including the other portion and the further thermal conditioning section, the separable part being configured to be removable from the detector module; b) providing a fluid to the support thermal conditioning section and the further thermal conditioning section; c) providing a vacuum environment around the detector; and d) providing the incidental charged particle beam for detection by the detector.

[0354]

[0363] Further clause 66. A method for detecting an incidental charged particle beam in a charged particle beam inspection tool, the method comprising: a) providing a detector module, the detector module being a detector configured to operate within a vacuum chamber, the detector module being configured to be alignable with an incidental charged particle beam path; a support for defining at least a portion of a wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough; and an electric shield configured to shield at least a portion of the detector module from electric fields, the electric shield being attached to the support such that during operation, a portion of the detector module is maintained shielded by the shield under the application of an external disturbance that deforms the support; b) providing a vacuum environment around the detector; and c) providing the incidental charged particle beam for detection by the detector.

[0355]

[0364] Further clause 67. A method of detecting an incident charged particle beam using a detector module according to any one of further clauses 1 to 60.

Claims

1. 1. A detector module for defining at least a portion of a wall of a vacuum chamber of a charged particle beam evaluation tool, comprising: a detector operating within the vacuum chamber, the detector being alignable with an incident charged particle beam path; a support for defining at least a portion of the wall of the vacuum chamber, the support including a feedthrough to which the detector is attached, the detector being electrically connected through the feedthrough, and an applied disturbance causing the support to deform; The detector module is configured such that the position of the detector is maintained relative to the incident charged particle beam path during operation of the detector in the presence of disturbances to the detector and / or support.

2. 2. The detector module of claim 1, wherein the disturbance of the support is symmetrical with respect to the incident charged particle beam path.

3. partially constituting a wall of the vacuum chamber for providing a vacuum environment; 3. The detector module of claim 1, wherein the detector is positioned within the vacuum chamber.

4. The feedthrough is a first side for exposure to an atmospheric environment; a second side for exposure to the vacuum chamber, opposite the first side, for covering an aperture of the vacuum chamber, and the detector is positioned on the second side of the feedthrough at a portion covering the aperture; The detector module according to any one of claims 1 to 3, comprising:

5. the detectors are positioned substantially symmetrically in a plane; 5. The detector module according to claim 1, wherein the plane includes the incident charged particle beam path and is perpendicular to the feedthrough.

6. further comprising a resilient member surrounding the feedthrough; 6. The detector module of claim 1, wherein the resilient members move in radially inward and outward directions in a plane perpendicular to the incident charged particle beam path.

7. 7. The detector module of claim 6, wherein the resilient member is configured such that deformation of the support due to a disturbance during operation of the detector is symmetrical with respect to the incident charged particle beam path.

8. 8. The detector module of claim 6 or 7, wherein the circumferential movement of the resilient member is limited.

9. The detector module of any one of claims 1 to 8, further comprising a rigid body.

10. 10. The detector module of claim 9, wherein the rigid body is on a first side of the feedthrough for exposure to an atmospheric environment.

11. 11. The detector module of claim 9 or 10, wherein the rigid body is configured such that deformation of the support is symmetrical with respect to the incident charged particle beam path during operation of the detector.

12. the rigid body is at least part of a thermal conditioning system that transfers heat from the support; Preferably, the thermal conditioning system comprises at least one supply connection to which fluid is provided during use and at least one return connection to which fluid is returned during use.

13. the thermal conditioning system defining at least a portion of a channel; The detector module of claim 12 , wherein the thermal conditioning system provides a conditioning fluid through the channel to transfer heat from the feedthrough.

14. an electronics unit including electronics in signal communication with the detector for controlling the detector and receiving data from the detector; Detector module according to any one of claims 1 to 13, wherein at least the electronics unit comprises a connection to the support.

15. the electronics unit is spaced apart from the support; and / or 15. The detector module of claim 14, wherein the electrical connections are positioned symmetrically with respect to the incident charged particle beam path.

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