Electrostatic lens design

Abstract

Disclosed herein is a manipulator lens device for focusing a charged particle beam, wherein the manipulator lens device comprises a first structure (401) through which an opening is formed, wherein a beam path substantially follows a longitudinal axis of the opening, a second structure (402) having a surface (406) surrounding the opening, a support (403) connecting the second structure to the first structure and surrounding the second structure, and an electrode arrangement (407) arranged on the surface (406) of the second structure, wherein a first surface (404) of the first structure (401) surrounds the opening, a second surface (405) of the first structure (401) surrounds the opening, the surface (406) of the second structure (402) is arranged between the first and second surfaces of the first structure along the longitudinal axis, the electrode arrangement (407) is separated from each of the first (404) and second (405) surfaces of the first structure (401) by a respective gap in a direction parallel to the longitudinal axis, wherein along the longitudinal axis a range of the support (403) is smaller than a range of the surface (406) of the second structure and / or of the electrode arrangement (407). Also disclosed is a multi-array lens configured to focus a plurality of charged particle sub-beams along a multi-beam path, wherein each lens in the array comprises the manipulator lens device.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to EP application 20160282.8, filed on February 28, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0003] The embodiments provided herein generally relate to charged particle irradiation equipment, and more specifically, to the design of beam manipulators used within charged particle beam irradiation equipment. Background Technology

[0004] When manufacturing semiconductor integrated circuit (IC) chips, undesirable pattern defects inevitably occur on the substrate (i.e., wafer) or mask during the manufacturing process, as a result of optical effects and incident particles, thereby reducing yield. Therefore, monitoring the extent of undesirable pattern defects is a critical process in IC chip manufacturing. More generally, the inspection and / or measurement of the surface of the substrate or other objects / materials is an important process during and / or after its manufacturing.

[0005] Pattern inspection tools with charged particle beams have been used to inspect objects, for example, to detect pattern defects. These tools typically employ electron microscopy techniques, such as scanning electron microscopy (SEM). In SEM, a primary electron beam of electrons at relatively high energies targets a final deceleration step so that it falls onto the sample with a relatively low landing energy. The electron beam is focused onto the sample as a probe spot. The interaction between the material structure at the probe spot and the landing electrons from the electron beam causes electrons to be emitted from the surface, such as secondary electrons, backscattered electrons, or Auger electrons. The generated secondary electrons can be emitted from the material structure of the sample. By scanning the primary electron beam, which serves as the probe spot, across the sample surface, secondary electrons can be emitted across the sample surface. By collecting these emitted secondary electrons from the sample surface, the pattern inspection tool can obtain an image representing the characteristics of the material structure of the sample surface.

[0006] Another application of charged particle beams is photolithography. The charged particle beam reacts with a resist layer on the surface of a substrate. By controlling the position of the charged particle beam on the resist layer, desired patterns can be created within the resist.

[0007] One way to improve the performance of tools used in this application is to use charged particle beam irradiation equipment that generates multiple beams of charged particles. By irradiating the sample with multiple beams of charged particles, each sub-beam in the multiple beams operates effectively in parallel.

[0008] There is often a need to improve the performance of charged particle beam irradiation equipment, which utilizes multiple beams of charged particles to irradiate a sample by means of development techniques that allow for a reduction in the spacing between sub-beams in a multi-beam system and / or an increase in the number of sub-beams that can be used. Summary of the Invention

[0009] The embodiments provided herein disclose a manipulator lens device for use in a charged particle beam irradiation apparatus. The charged particle beam irradiation apparatus can be used to generate multiple beams of charged particles. This manipulator lens device is particularly suitable for arrays of manipulator lens devices, wherein each manipulator lens device in the array is configured to operate on a corresponding sub-beam of the multiple charged particles. The charged particle beam irradiation apparatus can, for example, be included within an inspection apparatus or a lithography apparatus.

[0010] According to a first aspect of the invention, a manipulator lens device for focusing a charged particle beam is provided, wherein the manipulator lens device comprises: a first structure through which an opening is formed, wherein the path of the charged particle beam through the manipulator lens device is substantially along the longitudinal axis of the opening; a second structure having a surface, wherein the surface surrounds the opening in a plane orthogonal to and along the longitudinal axis for a first portion; a support member, wherein at least a portion of the support member in a plane orthogonal to and along the longitudinal axis for a first portion connects the second structure to the first structure and surrounds the second structure, such that the connection between the second structure and the first structure is symmetrical about the longitudinal axis; and an electrode arrangement disposed on the surface of the second structure, such that the electrode arrangement surrounds the longitudinal axis of the opening and is orthogonal to the longitudinal axis. In the plane, the surface of the second structure surrounds the electrode arrangement; wherein: the first surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a second portion of the longitudinal axis of the opening, the first surface surrounds the opening; the second surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a third portion of the longitudinal axis, the second surface surrounds the opening; the surface of the second structure is arranged between the first surface and the second surface of the first structure along the longitudinal axis; the electrode arrangement is separated from the first surface of the first structure in a direction parallel to the longitudinal axis, such that a first gap exists between the electrode arrangement and the first surface of the first structure; and the electrode arrangement is separated from the second surface of the first structure in a direction parallel to the longitudinal axis, such that a second gap exists between the electrode arrangement and the second surface of the first structure.

[0011] According to a second aspect of the invention, a manipulator lens array is provided, the manipulator lens array comprising a plurality of manipulator lens devices according to the first aspect; wherein the openings of all manipulator lens devices are formed by the same first structure.

[0012] According to a third aspect of the invention, a method is provided for incorporating a first portion of a manipulator lens assembly into a second portion of the manipulator lens assembly.

[0013] According to a fourth aspect of the invention, a single lens (Einzellens) for focusing a charged particle beam is provided, wherein the single lens includes: a focusing electrode arrangement to which a voltage for focusing the charged particle beam is applied; a first electrode arrangement on the body of the single lens; and a second electrode arrangement on the body of the single lens, wherein the focusing electrode arrangement is arranged between the first and second ground electrode arrangements along the longitudinal axis of the single lens, and the focusing electrode arrangement is electrically isolated from the first and second ground electrode arrangements; wherein the focusing electrode arrangement includes: a structure on which one or more electrodes are formed; and a support member that mechanically connects the structure to the body of the single lens in a plane orthogonal to the longitudinal axis by a connection symmetrical about the longitudinal axis.

[0014] According to a fifth aspect of the invention, a single lens is provided, configured to focus a beam of charged particles in a beam path during use, wherein the single lens comprises: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be disposed at a second potential, the focusing electrode extending along and symmetrically around the beam path; a second electrode configured to be disposed substantially at the first potential; and a support member configured to support the focusing electrode, wherein the focusing electrode is configured to be electrically isolated from the first and second electrodes, and the focusing electrode extends further along the beam path than the support member, such that a dimensional difference along the beam path between the support member and the focusing electrode provides a creep length parallel to the beam path.

[0015] According to a sixth aspect of the invention, a single lens is provided, configured to focus a charged particle beam in a beam path during use, wherein the single lens includes: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be at a second potential, wherein the focusing electrode extends along and symmetrically around the beam path, and the focusing electrode includes an electrode surface on a structure; a second electrode configured to be substantially at the first potential; and a support member configured to support the focusing electrode, the electrode being arranged along the beam path such that the focusing electrode is between the first and second electrodes, wherein the focusing electrode is configured to be electrically isolated from the first and second electrodes.

[0016] According to a seventh aspect of the invention, a multi-array single lens is provided, configured in use to focus a plurality of charged particle sub-beams along a multi-beam path, wherein each single lens in the array includes: a focusing electrode located midway between an upstream electrode and a downstream electrode along the beam path and configured to be at a different potential from the upstream and downstream electrodes, wherein the focusing electrode is electrically isolated from the upstream and downstream electrodes; wherein the focusing electrode includes: an electrode surface; and a support member; wherein the support member is substantially symmetrical about the beam path; configured to support the electrode surface in a plane orthogonal to the beam path; and configured to be electrically connected to the electrode surface.

[0017] According to an eighth aspect of the invention, a multi-array single lens is provided, configured in use to focus a plurality of charged particle sub-beams along a multi-beam path, wherein each single lens in the array includes: a focusing electrode located between an upstream electrode and a downstream electrode and configured to be isolated from and at a different potential from the upstream and downstream electrodes, the focusing electrode extending along and substantially symmetrically around the beam path; and a support member configured to support the focusing electrode; wherein the focusing electrode extends further along the beam path than the support member, such that the dimensional difference between the support member and the focusing electrode along the beam path provides a creep length parallel to the beam path.

[0018] According to a ninth aspect of the invention, a multi-array lens is provided, configured to focus a plurality of charged particle sub-beams along a multi-beam path during use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential from the inlet electrode during operation; and a support for supporting and electrically isolating the focusing electrode, wherein the focusing electrode is substantially rotationally symmetric about the sub-beam path.

[0019] According to a tenth aspect of the invention, a multi-array lens is provided, configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential than the inlet electrode, wherein the focusing electrode includes: an electrode surface; and a support member; wherein the support member is symmetrical about the sub-beam path; configured to support the electrode surface in a plane orthogonal to the beam path; configured to electrically isolate the focusing electrode from the inlet electrode; and configured to electrically connect the electrode surface.

[0020] According to an eleventh aspect of the invention, a multi-array single lens is provided, configured in use to focus a plurality of charged particle sub-beams along a multi-beam path, wherein each single lens in the array includes: a focusing electrode located between upstream and downstream electrodes and configured to be isolated from and at a different potential from the upstream and downstream electrodes, wherein the focusing electrode extends along and substantially symmetrically around the beam path; and a support member configured to support the focusing electrode; wherein the focusing electrode extends further along the sub-beam path than the support member, such that the dimensional difference between the support member and the focusing electrode along the beam path provides shielding of the beam path by the support member.

[0021] According to a twelfth aspect of the invention, a multi-array lens is provided, configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential from the inlet electrode; and a support member configured to support the focusing electrode relative to the inlet electrode, wherein the focusing electrode and the support member are configured such that the lens generates a rotationally symmetric field about the sub-beam path in operation.

[0022] Other advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which certain embodiments of the invention are illustrated by way of description and example. Attached Figure Description

[0023] The above and other aspects of this disclosure will become more apparent from the description of exemplary embodiments in conjunction with the accompanying drawings.

[0024] Figure 1 This is a schematic diagram illustrating an exemplary charged particle beam inspection device.

[0025] Figure 2 It is shown as Figure 1 A schematic diagram of an exemplary multi-beam device, representing a portion of an exemplary charged particle beam inspection device.

[0026] Figure 3 It shows Figure 1 A schematic diagram of an exemplary multi-beam device with an exemplary configuration of the source conversion unit of an exemplary charged particle beam inspection device.

[0027] Figure 4 A cross-section of a schematic lens design according to the first embodiment is shown.

[0028] Figure 5 A cross-section of a schematic lens design according to the first embodiment is shown.

[0029] Figure 6This is a schematic plan view showing the cross-section of a lens according to the first embodiment.

[0030] Figure 7 A cross-section of the lens array according to an embodiment is shown.

[0031] Figure 8 A cross-section of a lens array including a lens according to the second embodiment is shown.

[0032] Figure 9 A cross-section of a schematic lens design according to a third embodiment is shown.

[0033] Figure 10 A cross-section of a lens array including a lens according to a third embodiment is shown.

[0034] Figure 11 A cross-section of a lens array including a lens according to the fourth embodiment is shown. Detailed Implementation

[0035] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, wherein the same numbers in different drawings denote the same or similar elements unless otherwise stated. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the invention. Rather, they are merely examples of devices and methods consistent with the aspects of the invention relevance described in the appended claims.

[0036] Enhanced computing power (reduced physical size of the device) in electronic devices can be achieved by significantly increasing the packaging density of circuit components (such as transistors, capacitors, diodes, etc.) on an IC chip. This has been achieved through increased resolution, which allows for the fabrication of smaller structures. For example, the IC chip in a smartphone can include more than 2 billion transistors, each smaller than 1 / 1000th the size of a human hair; the IC chip was the size of a thumbnail and was available in 2019 or earlier. Therefore, it is not surprising that semiconductor IC manufacturing is a complex and time-consuming process with hundreds of individual steps. Even an error in one step can significantly affect the functionality of the final product. A single “fatal defect” can cause a device to fail. The goal of a manufacturing process is to improve the overall process yield. For example, for a 50-step process (where one step can indicate the number of layers formed on the wafer), to achieve a 75% yield, each individual step must have a yield greater than 99.4%. If individual steps have a yield of 95%, the overall process yield will be as low as 7%.

[0037] While high process yields are required in IC chip manufacturing facilities, maintaining high substrate (i.e., wafer) throughput (defined as the number of substrates processed per hour) is also important. The presence of defects can impact both high process yields and high substrate throughput. This is especially true in situations where operator intervention is required to inspect for defects. Therefore, high-throughput detection and identification of micron- and nanometer-scale defects using inspection tools such as scanning electron microscopy (“SEM”) is crucial for maintaining high yields and low costs.

[0038] A Sequencing Analyzer (SEM) comprises a scanning apparatus and a detector device. The scanning apparatus includes an illumination device and a projection device. The illumination device includes an electron source for generating primary electrons, and the projection device is used to scan a sample, such as a substrate, using one or more focused beams of primary electrons. The primary electrons interact with the sample and generate secondary electrons. As the sample is scanned, the detector device captures the secondary electrons from the sample, allowing the SEM to create an image of the scanned area of ​​the sample. For high-throughput inspection, some inspection devices use multiple focused beams, i.e., multiple beams of primary electrons. The component beams in a multi-beam system can be referred to as sub-beams or split beams. Multiple beams can scan different portions of the sample simultaneously. Therefore, multi-beam inspection devices are able to inspect samples at much higher speeds than single-beam inspection devices.

[0039] In multi-beam inspection equipment, some primary electron beams deviate from the central axis of the scanning device, i.e., the midpoint of the primary electron optical axis. To ensure that all electron beams reach the sample surface at substantially the same incident angle, it is necessary to manipulate sub-beam paths with a greater radial distance from the central axis, shifting them by a larger angle than paths closer to the central axis. This stronger manipulation can introduce aberrations that result in blurred and out-of-focus images of the sample substrate. In particular, for sub-beam paths not on the central axis, the aberrations of the sub-beams can increase with radial displacement from the central axis. When secondary electrons are detected, these aberrations may remain associated with the secondary electrons. Therefore, these aberrations degrade the quality of the image created during inspection.

[0040] The following describes the implementation of a known multi-beam inspection device.

[0041] The accompanying drawings are schematic. Therefore, for clarity, the relative dimensions of the components in the drawings are enlarged. In the following description of the drawings, the same or similar reference numerals refer to the same or similar components or entities, and only differences with respect to various embodiments are described. Although the description and drawings are directed to electro-optical devices, it should be understood that these embodiments are not intended to limit this disclosure to specific charged particles. Therefore, references to electrons in this document can be more generally considered as references to charged particles, where charged particles are not necessarily electrons.

[0042] Now for reference Figure 1 , Figure 1This is a schematic diagram illustrating an exemplary charged particle beam inspection device 100. Figure 1 The charged particle beam inspection device 100 includes a main chamber 10, a loading and locking chamber 20, an electron beam tool 40, an equipment front-end module (EFEM) 30, and a controller 50. The electron beam tool 40 is located inside the main chamber 10.

[0043] EFEM 30 includes a first loading port 30a and a second loading port 30b. EFEM 30 may include additional loading ports(s). For example, the first loading port 30a and the second loading port 30b may receive a front-opening substrate integration chamber (FOUP) containing a substrate (e.g., a semiconductor substrate or a substrate made of other materials(s)) or a sample to be inspected (substrate, wafer, and sample are collectively referred to below as “sample”). One or more robotic arms (not shown) in EFEM 30 transport the sample to the loading locking chamber 20.

[0044] Loading lock chamber 20 is used to remove gas surrounding the sample. This creates a vacuum where the local gas pressure is lower than the pressure in the surrounding environment. Loading lock chamber 20 can be connected to a loading lock vacuum pump system (not shown), which removes gas particles from loading lock chamber 20. Operation of the loading lock vacuum pump system enables the loading lock chamber to reach a first pressure below atmospheric pressure. After reaching the first pressure, one or more robotic arms (not shown) transport the sample from loading lock chamber 20 to main chamber 10. Main chamber 10 is connected to a main chamber vacuum pump system (not shown). The main chamber vacuum pump system removes gas particles from main chamber 10, causing the pressure around the sample to reach a second pressure below the first pressure. After reaching the second pressure, the sample is transported to an electron beam tool, through which the sample can be examined. Electron beam tool 40 may include multi-beam electron optics.

[0045] The controller 50 is electrically connected to the electron beam tool 40. The controller 50 may be a processor (such as a computer) configured to control the charged particle beam inspection device 100. The controller 50 may also include a processing circuitry system configured to perform various signal and image processing functions. Although the controller 50 is... Figure 1 The controller 50 is shown outside the structure comprising the main chamber 10, the loading and locking chamber 20, and the EFEM 30; however, it should be understood that the controller 50 may be part of this structure. The controller 50 may be located in one of the components of the charged particle beam inspection apparatus, or it may be distributed across at least two of the components. While this disclosure provides an example of a main chamber 10 for housing electron beam inspection tools, it should be noted that aspects of this disclosure are not limited, in their broadest sense, to the chamber housing electron beam inspection tools. Of course, it should be understood that the above principles can also be applied to other arrangements of other tools and apparatuses operating under a second pressure.

[0046] Now for reference Figure 2 , Figure 2 The diagram illustrates the inclusion of... Figure 1 This is a schematic diagram of an exemplary electron beam tool 40, a part of an exemplary charged particle beam inspection apparatus 100. The multi-beam electron beam tool 40 (also referred to herein as apparatus 40) includes an electron source 201, an aperture plate 271, a focusing lens 210, a source conversion unit 220, a primary projection device 230, a motorized stage 209, and a sample holder 207. The electron source 201, aperture plate 271, focusing lens 210, and source conversion unit 220 are components of the irradiation apparatus included in the multi-beam electron beam tool 40. The sample holder 207 is supported by the motorized stage 209 to hold a sample 208 (e.g., a substrate or mask) for inspection. The multi-beam electron beam tool 40 may also include a secondary projection device 250 and an associated electron detection device 240. The primary projection device 230 may include an objective lens 231. The electron detection device 240 may include a plurality of detection elements 241, 242, and 243. The beam splitter 233 and the deflection scanning unit 232 can be located inside the primary projection device 230.

[0047] The components used to generate the primary beam can be aligned with the primary electron optical axis of device 40. These components may include: an electron source 201, a bore plate 271, a focusing lens 210, a source conversion unit 220, a beam splitter 233, a deflection scanning unit 232, and a primary projection device 230. The secondary projection device 250 and its associated electronic detection device 240 can be aligned with the secondary electron optical axis 251 of device 40.

[0048] The primary electron optical axis 204 is formed by the electron optical axis of the electron beam tool 40, which is part of the irradiation device. The secondary electron optical axis 251 is the electron optical axis of the electron beam tool 40, which is part of the detection device. The primary electron optical axis 204 may also be referred to herein as the primary optical axis (for ease of reference) or the charged particle optical axis. The secondary electron optical axis 251 may also be referred to herein as the secondary optical axis or the secondary charged particle optical axis.

[0049] Electron source 201 may include a cathode (not shown) and an extractor or anode (not shown). During operation, electron source 201 is configured to emit electrons from the cathode as primary electrons. The primary electrons are extracted or accelerated by the extractor and / or anode to form a primary electron beam 202, which forms a primary beam cross (virtual or real) 203. The primary electron beam 202 can be visualized as being emitted from the primary beam cross 203.

[0050] In this arrangement, the primary electron beam is multi-beamed when it reaches the sample (and preferably before it reaches the projection device). This multi-beaming can be generated from the primary electron beam in a variety of different ways. For example, the multi-beams can be generated by a multi-beam array located before the crossover, a multi-beam array located in the source conversion unit 220, or a multi-beam array located at any point between these locations. The multi-beam array can include multiple electron beam manipulation elements arranged in an array across the beam path. Each manipulation element can influence the primary electron beam to generate a sub-beam. Thus, the multi-beam array interacts with the incident primary beam path to generate a multi-beam path downstream of the multi-beam array.

[0051] In operation, the aperture plate 271 is configured to block peripheral electrons in the primary electron beam 202 to reduce the Coulomb effect. The Coulomb effect can amplify the size of each probe spot in the probe spots 221, 222, and 223 of the primary sub-beams 211, 212, and 213, thus reducing the inspection resolution. The aperture plate 271 may also be referred to as a Coulomb aperture array.

[0052] The focusing lens 210 is configured to focus the primary electron beam 202. The focusing lens 210 can be designed to focus the primary electron beam 202 into a parallel beam and incident perpendicularly onto the source conversion unit 220. The focusing lens 210 can be a movable focusing lens, configured such that the position of its first principal plane is movable. The movable focusing lens can be configured to be magnetic. The focusing lens 210 can be an anti-rotation focusing lens and / or it can be movable.

[0053] Source conversion unit 220 may include an image forming element array, an aberration compensator array, a beam confinement aperture array, and a pre-bending micro-deflector array. The pre-bending micro-deflector array can deflect multiple primary sub-beams 211, 212, 213 of the primary electron beam 202 to enter the beam confinement aperture array, the image forming element array, and the aberration compensator array perpendicularly. In this arrangement, the image forming element array can function as a multi-beam array to generate multiple sub-beams, i.e., primary sub-beams 211, 212, 213, in a multi-beam path. The image forming array may include multiple electron beam manipulators, such as micro-deflectors or microlenses (or a combination of both), to influence the multiple primary sub-beams 211, 212, 213 of the primary electron beam 202 and form multiple parallel images (virtual or real) of the primary beam cross 203, each primary sub-beam of 211, 212, and 213 corresponding to one parallel image. 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 microlenses to compensate for field curvature aberrations in primary sub-beams 211, 212, and 213. The astigmatism compensator array may include multiple micro-astigmatism reducers to compensate for astigmatic aberrations in primary sub-beams 211, 212, and 213. The beam-limiting aperture array may be configured to limit the diameters of the individual primary sub-beams 211, 212, and 213. Figure 2 Three primary sub-bundles 211, 212, and 213 are shown as examples, and it should be understood that the source conversion unit 220 can be configured to form any number of primary sub-bundles. The controller 50 can be connected to... Figure 1 The charged particle beam inspection equipment 100 includes various components such as the source conversion unit 220, the electronic detection device 240, the primary projection device 230, or the motorized stage 209. As explained in further detail below, the controller 50 can perform various image and signal processing functions. The controller 50 can also generate various control signals to manage the operation of the charged particle beam inspection equipment (including charged particle multi-beam equipment).

[0054] The focusing lens 210 can also be configured to adjust the current of the primary sub-bundles 211, 212, 213 downstream of the source conversion unit 220 by changing the focusing capability of the focusing lens 210. Alternatively, or additionally, the current of the primary sub-bundles 211, 212, 213 can be changed by altering the radial dimension of the beam-limiting aperture within the beam-limiting aperture array corresponding to each primary sub-bundle. The current can be changed by altering the radial dimension of the beam-limiting aperture and the focusing capability of the focusing lens 210. If the focusing lens is movable and magnetic, the off-axis sub-bundles 212 and 213 can cause the source conversion unit 220 to be illuminated at a rotational angle. The rotational angle changes with the focusing capability of the movable focusing lens or the position of the first principal plane. The focusing lens 210, acting as an anti-rotation focusing lens, can be configured to maintain a constant rotational angle when the focusing capability of the focusing lens 210 changes. When the focusing capability of the focusing lens 210 and the position of its first principal plane change, this movable focusing lens 210 can maintain the rotation angle.

[0055] Objective 231 can be configured to focus sub-beams 211, 212 and 213 onto sample 208 for inspection, and can form three probe spots 221, 222 and 223 on the surface of sample 208.

[0056] Beam splitter 233 may be, for example, a Wien filter including an electrostatic deflector that generates an electrostatic dipole field and a magnetic dipole field. Figure 2 (Not shown in the diagram). In operation, the beam splitter 233 can be configured to apply electrostatic forces to the individual electrons of the primary sub-bundles 211, 212, and 213 via an electrostatic dipole field. The electrostatic forces are equal in magnitude but opposite in direction to the magnetic forces applied to the individual electrons by the magnetic dipole field of the beam splitter 233. Therefore, the primary sub-bundles 211, 212, and 213 can pass through the beam splitter 233 at least substantially straight with at least substantially zero deflection angle.

[0057] In operation, the deflection scanning unit 232 is configured to deflect primary sub-beams 211, 212, and 213 to scan probe spots 221, 222, and 223 across various scanning regions in the surface portion of sample 208. In response to the incidence of primary sub-beams 211, 212, and 213 or probe spots 221, 222, and 223 on sample 208, electrons comprising secondary electrons and backscattered electrons are generated from sample 208. The secondary electrons propagate in three secondary electron beams 261, 262, and 263. Secondary electron beams 261, 262, and 263 typically contain secondary electrons (with electron energies ≤50 eV) and may also contain at least some of backscattered electrons (with electron energies between 50 eV and the landing energies of primary sub-beams 211, 212, and 213). Beam splitter 233 is arranged to deflect the paths of secondary electron beams 261, 262, and 263 toward secondary projection device 250. Secondary projection device 250 then focuses the paths of secondary electron beams 261, 262, and 263 onto multiple detection areas of electron detection device 240. Detection areas may be separate detection elements 241, 242, and 243 configured to detect corresponding secondary electron beams 261, 262, and 263. Detection areas generate corresponding signals, which are sent to controller 50 or signal processing system (not shown), for example, to construct an image of the corresponding scan area of ​​sample 208.

[0058] Detection elements 241, 242, and 243 can detect corresponding secondary electron beams 261, 262, and 263. When the secondary electron beams are incident on detection elements 241, 242, and 243, these elements can generate corresponding intensity signal outputs (not shown). The outputs can be directed to an image processing system (e.g., controller 50). Each detection element 241, 242, and 243 can include one or more pixels. The intensity signal output of the detection element can be the sum of signals generated by all pixels within the detection element.

[0059] The controller 50 may include an image processing system comprising an image acquirer (not shown) and a storage device (not shown). For example, the controller may include a processor, computer, server, mainframe, terminal, personal computer, any type of mobile computing device, or combinations thereof. The image acquirer may include at least a portion of the controller's processing capabilities. Therefore, the image acquirer may include at least one or more processors. The image acquirer may be communicatively coupled to an electronic detection device 240 of a device 40 that allows signal communication, such as an electrical conductor, fiber optic cable, portable storage medium, IR, Bluetooth, the Internet, wireless network, radio, or combinations thereof. The image acquirer may receive signals from the electronic detection device 240, process data included in the signals, and construct an image based thereon. Thus, the image acquirer can acquire an image of sample 208. The image acquirer may also perform various post-processing functions, such as generating contours, overlaying indicators on the acquired image, etc. The image acquirer may be configured to perform adjustments to the brightness and contrast of the acquired image, etc. The storage device may be a storage medium such as a hard disk, flash drive, cloud storage, random access memory (RAM), or other types of computer-readable storage. The storage device can be coupled to the image acquirer and can be used to save the scanned raw image data as an initial image and to save a post-processed image.

[0060] The image acquirer can acquire one or more images of a sample based on imaging signals received from the electronic detection device 240. The imaging signals may correspond to a scanning operation used for imaging charged particles. The acquired image may be a single image comprising multiple imaging regions. The single image may be stored in a storage device. The single image may be an initial image that can be divided into multiple regions. Each of these regions may include an imaging area containing features of the sample 208. The acquired images may include multiple images of a single imaging region of the sample 208 sampled multiple times over a period of time. Multiple images may be stored in a storage device. The controller 50 may be configured to perform image processing steps using multiple images of the same location on the sample 208.

[0061] The controller 50 may include a measurement circuitry (e.g., an analog-to-digital converter) to obtain the distribution of detected secondary electrons. The electron distribution data collected during the detection time window can be combined with corresponding scan path data of each of the primary sub-beams 211, 212, and 213 incident on the sample surface to reconstruct an image of the sample structure under inspection. The reconstructed image can be used to reveal various features of the internal or external structure of the sample 208. Thus, the reconstructed image can be used to reveal any defects that may be present in the sample.

[0062] The controller 50 can control the motorized stage 209 to move the sample 208 during sample inspection. At least during sample inspection, the controller 50 can cause the motorized stage 209 to move the sample 208 in a certain direction, for example, at a constant speed, preferably continuously. The controller 50 can control the movement of the motorized stage 209 such that it changes the speed of the sample 208 according to various parameters. For example, the controller can control the stage speed (including its direction) based on the characteristics of the inspection steps in the scanning process.

[0063] although Figure 2 The device 40 is shown to use three primary electron sub-beams; however, it should be understood that the device 40 may use two or more primary electron sub-beams. This disclosure does not limit the number of primary electron beams used in the device 40.

[0064] Now for reference Figure 3 , Figure 3 It's a diagram. Figure 1 A schematic diagram of an exemplary multi-beam device with an exemplary configuration of the source conversion unit of an exemplary charged particle beam inspection apparatus. Device 300 may include an electron source 301, a pre-beam forming aperture array 372, and a focusing lens 310 (similar to...). Figure 2 (Converging lens 210), source conversion unit 320, objective lens 331 (similar to) Figure 2 Objective 231) and sample 308 (similar to) Figure 2 (Sample 208). The electron source 301, pre-beam forming aperture array 372, and focusing lens 310 can be components of the irradiation device included in the device 300. The source conversion unit 320 and objective lens 331 can be components of the projection device included in the device 300. The source conversion unit 320 can be similar to... Figure 2 The source conversion unit 220, wherein Figure 2 The image forming element array is an image forming element array 322. Figure 2 The aberration compensator array is an aberration compensator array 324. Figure 2 The beam-confined aperture array is a beam-confined aperture array 321. Figure 2The pre-bent micro-deflector array is a pre-bent micro-deflector array 323. An electron source 301, a pre-beamforming aperture array 372, a focusing lens 310, a source conversion unit 320, and an objective lens 331 are aligned with the primary electron optical axis 304 of the device. The electron source 301 generates a primary electron beam 302 that is generally along the primary electron optical axis 304 and has source crossovers (virtual or real) 301S. The pre-beamforming aperture array 372 cuts the peripheral electrons of the primary electron beam 302 to reduce the Coulomb effect that occurs as a result. The Coulomb effect is a source of aberrations in the sub-beams due to the interaction between electrons in different sub-beam paths. Through the pre-beamforming aperture array 372 of the pre-beamforming mechanism, the primary electron beam 302 can be trimmed into a specified number of sub-beams, such as three sub-beams 311, 312, and 313. Although three sub-bundles and their paths are mentioned in the preceding and following descriptions, it should be understood that this description is intended to apply to devices, tools, or systems with any number of sub-bundles.

[0065] Source conversion unit 320 may include a sub-beam limiting aperture array 321 having a beam limiting aperture configured to limit sub-beams 311, 312, and 313 of the primary electron beam 302. Source conversion unit 320 may also include an image forming element array 322 having image forming micro-deflectors 322_1, 322_2, and 322_3. A corresponding micro-deflector is associated with the path of each sub-beam. Micro-deflectors 322_1, 322_2, and 322_3 are configured to deflect the paths of sub-beams 311, 312, and 313 toward the electron optical axis 304. The deflected sub-beams 311, 312, and 313 form a virtual image of the source cross 301S. The virtual image is projected onto the sample 308 through objective lens 331, and detector spots are formed thereon, which are three detector spots 391, 392, and 393. Each probe spot corresponds to the incident position of the sub-beam path on the sample surface. The source conversion unit 320 may also include an aberration compensator array 324 configured to compensate for aberrations in each sub-beam. Aberrations in each sub-beam are typically present in probe spots 391, 392, and 393 that will be formed on the sample surface. The aberration compensator array 324 may include an array of field curvature compensators (not shown) with microlenses. The field curvature compensators and microlenses are configured to compensate for sub-beams with significant field curvature aberrations in probe spots 391, 392, and 393. The aberration compensator array 324 may include an array of astigmatism compensators (not shown) with micro-astigmatism ablation devices. The micro-astigmatism ablation devices are controlled to operate on the sub-beams to compensate for astigmatic aberrations that are otherwise present in probe spots 391, 392, and 393.

[0066] The source conversion unit 320 may further include a pre-bent micro-deflector array 323 having pre-bent micro-deflectors 323_1, 323_2, and 323_3 to bend sub-beams 311, 312, and 313, respectively. The pre-bent micro-deflectors 323_1, 323_2, and 323_3 can bend the paths of the sub-beams onto the sub-beam confinement aperture array 321. The sub-beam paths incident on the sub-beam confinement aperture array 321 can be orthogonal to the plane of orientation of the sub-beam confinement aperture array 321. A focusing lens 310 can guide the paths of the sub-beams onto the sub-beam confinement aperture array 321. The focusing lens 310 can focus the three sub-beams 311, 312, and 313 into parallel beams along the primary electron optical axis 304, such that they are perpendicularly incident on the source conversion unit 320, which can correspond to the sub-beam confinement aperture array 321.

[0067] The image forming element array 322, the aberration compensator array 324, and the pre-bending micro-deflector array 323 may include multi-layer sub-beam manipulation devices, some of which may be in the form of arrays, such as micro-deflectors, microlenses, or micro-astigmatism reducers.

[0068] In the source conversion unit 320, sub-beams 311, 312, and 313 of the primary electron beam 302 are deflected toward the primary electron optical axis 304 by micro-deflectors 322_1, 322_2, and 322_3 of the image forming element array 322, respectively. It should be understood that the path of sub-beam 311 may already correspond to the electron optical axis 304 before reaching the micro-deflector 322_1, and therefore the path of sub-beam 311 may not be deflected by the micro-deflector 322_1.

[0069] Objective lens 331 focuses the sub-beams onto the surface of sample 308, that is, it projects three virtual images onto the sample surface. The three images formed by the three sub-beams 311 to 313 on the sample surface form three detector spots 391, 392, and 393 on them. The deflection angles of sub-beams 311 to 313 are adjusted by objective lens 331 to reduce off-axis aberrations of the three detector spots 391 to 393. The three deflected sub-beams thus pass through or approach the front focal point of objective lens 331.

[0070] Figure 2 and Figure 3 At least some of the components mentioned above may be referred to individually or in combination as manipulator arrays or manipulators, because they manipulate one or more bundles or sub-bundles of charged particles.

[0071] The aforementioned multi-beam inspection tool includes a multi-beam charged particle optical device with a single charged particle source. The charged particle optical device includes an illumination device and a projection device. The illumination device can generate multiple beams of charged particles from an electron beam from the source. The projection device projects multiple beams of charged particles toward the sample. At least a portion of the sample surface can be scanned using the multiple beams of charged particles.

[0072] The embodiments provide novel designs for lenses in irradiation and / or projection devices for charged particles. The lenses can manipulate the beam or sub-beam by focusing or defocusing the charged particle beam.

[0073] The lens according to the embodiment is particularly suitable for lens arrays. The lens has a compact design, so the lenses within the array can be close to each other. In the lens array according to the embodiment, the beam of charged particles manipulated by each lens can be a sub-beam of multiple charged particles.

[0074] Each lens according to the embodiments may be referred to as a manipulator lens device and / or a microlens.

[0075] Figure 4 A cross-section of the lens design according to the first embodiment is shown. The cross-section lies in a plane encompassed by the path of the charged particle beam through the lens. Typically, the beam path extends from the top to the bottom of the page.

[0076] The lens may include a substrate. The lens may be formed in at least two layers of the semiconductor substrate. However, as described in more detail below, the lens may be formed in at least four layers of the semiconductor substrate.

[0077] The lens includes a first structure 401 in which an opening is formed. In a plan view, the opening may be circular. The opening is an aperture for the path of a charged particle beam through the lens. The lens is arranged to manipulate (e.g., focus or defocus) the charged particles passing through the opening. The path of the charged particles through the opening may be substantially along and / or parallel to the longitudinal axis of the opening, for example, if the multi-beam path is substantially collimated before entering the lens of a multi-lens array. Alternatively, the path of the charged particles through the opening may be at an angle relative to the longitudinal axis of the opening. The longitudinal axis of the opening may be parallel to the charged particle optical axis of the portion of the device / tool ​​in which the lens is used.

[0078] The first structure 401 may include multiple layers of a semiconductor substrate. For example, the first structure 401 may include at least four layers of a semiconductor substrate.

[0079] The first structure 401 includes a first surface 404 of a wall providing an opening, the wall extending from a first end of the opening in a direction along the longitudinal axis of the opening. The first surface 404 may be located at an upstream end of the first structure 401. The first surface 404 may be an electrode arrangement including one or more electrodes. The first surface 404 may provide a ground potential.

[0080] The first structure 401 includes a second surface 405 that provides a wall for an opening, extending from a second end of the opening in a direction along the longitudinal axis of the opening. The second surface 405 may be located at a downstream end of the first structure 401. The second end of the opening is opposite to the first end of the opening. The second surface 405 may be an electrode arrangement including one or more electrodes. The second surface 405 may provide a ground potential.

[0081] The first surface 404 and the second surface 405 can be at the same potential, which can be ground potential or a different potential. Alternatively, the potential of the first surface 404 can be different from the potential of the second surface 405. The first surface 404 and the second surface 405 can be at any potential, and are not limited to ground potential.

[0082] The lens includes a second structure 402. The second structure 402 may be annular, such that in a plane orthogonal to the longitudinal axis of the opening and along a first portion of the longitudinal axis of the opening, the second structure 402 surrounds the opening.

[0083] The second structure 402 includes a surface 406. An electrode arrangement 407 is disposed on the surface 406 of the second structure 402. The electrode arrangement 407 provides a wall for an opening that extends in a direction along the longitudinal axis of the opening. In a plane orthogonal to the longitudinal axis, the electrode arrangement 407 surrounds the opening, and the surface of the second structure 402 surrounds the electrode arrangement 407.

[0084] Electrode arrangement 407 may include one or more electrodes. Each electrode of electrode arrangement 407 may provide a potential different from the potential of the first surface 404 and the second surface 405. By applying a potential at electrode arrangement 407 that is different from the potential applied at the first surface 404 and the second surface 405, the lens can manipulate a charged particle beam according to the known operating principles of a single lens. That is, when operating as a single lens, the first and second surfaces have a common potential, and the surfaces of one or more electrodes of the electrode arrangement have potentials different from the first and second surfaces.

[0085] like Figure 4 As shown, the electrode arrangement 407 on the second structure 402 can extend at both ends of the second structure 402 in at least one plane orthogonal to the longitudinal axis of the opening. Alternatively, the electrode arrangement 407 can extend only at one end of the second structure 402.

[0086] The second structure 402 is physically attached to the first structure 401 by a support member 403. The support member 403 may be annular, such that it surrounds the second structure 402 in a plane orthogonal to the longitudinal axis of the opening and along at least a portion of a first portion of the longitudinal axis. The support member 403 provides a connection between the second structure 402 and the first structure 401, the connection being uniform and / or symmetrical about the longitudinal axis of the opening.

[0087] like Figure 4 As shown, along the longitudinal axis, the range of the support member 403 can be smaller than the range of the surface of the second structure 402. The longitudinal midpoint of the support member 403 can be in the same plane as the longitudinal midpoint of the second structure 402.

[0088] The lens includes a feed line 408 on the electrode arrangement 407 of the second structure 402. The feed line 408 can be positioned in a plane orthogonal to the longitudinal axis of the opening, and part or all of the feed line 408 can surround the opening. The feed line 408 is at least electrically connected to the electrode arrangement 407 and can also be physically connected to the electrode arrangement 407. The connection between the feed line 408 and the electrode arrangement 407 can be at the longitudinal midpoint of the electrode arrangement 407, which can also be the longitudinal midpoint of the second structure 402. The feed line 408 can be connected to the electrode arrangement 407 by passing through a support 403 in a plane orthogonal to the longitudinal axis and entering the second structure 402.

[0089] The first surface 404 of the first structure 401 is in a plane orthogonal to the longitudinal axis of the opening and surrounds the opening along at least a second portion of the longitudinal axis of the opening.

[0090] The second surface 405 of the first structure 401 is in a plane orthogonal to the longitudinal axis of the opening and surrounds the opening along at least a third portion of the longitudinal axis of the opening.

[0091] Along the longitudinal axis of the opening, an electrode arrangement 407 on the surface of the second structure 402 is arranged between the first and second surfaces of the first structure 401.

[0092] The electrode arrangement 407 on the surface of the second structure 402 is separated from the first surface 404 of the first structure 401 in a direction parallel to the longitudinal axis of the opening. Therefore, a first gap exists between the electrode arrangement 407 and the first surface 404 of the first structure 401. The surface of the gap (e.g., orthogonal to the beam path) can provide the surfaces of the electrode arrangement 407 and the first surface 404 of the first structure facing each other.

[0093] The electrode arrangement 407 on the surface of the second structure 402 is separated from the second surface of the first structure 401 in a direction parallel to the longitudinal axis of the opening. Therefore, a second gap exists between the electrode arrangement 407 and the second surface of the first structure 401. The surface of the gap (e.g., orthogonal to the beam path) can provide both the surface of the electrode arrangement 407 and the second surface 405 of the first structure 401.

[0094] At least due to the first and second gaps, the electrode arrangement 407 on the second structure 402 is physically separated from the first and second surfaces. The length of each of the first and second gaps is determined such that the electrode arrangement 407 on the second structure 402 is electrically isolated from the first and second surfaces when the lens is used under the intended operating conditions. That is, the electrode arrangement 407 is connected to other conductors of the lens arrangement, such as the first structure 401, via an electrically isolated support.

[0095] The lens can be substantially symmetrical about the longitudinal axis of the opening.

[0096] The overall structure of the lens is that of a single lens. In this single lens, the upstream and downstream electrodes have substantially the same potential, while the intermediate electrode has a different potential. This potential difference allows the beam to leave and exit the single lens with substantially the same energy or velocity, and enables the intermediate electrode to achieve a focusing effect on the beam. Therefore, the potential difference between the electrode arrangement 407 on the second structure 402 and the first and second surfaces of the first structure 401 can have a focusing effect on charged particles passing through the opening.

[0097] The second structure 402 is connected to the first structure 401 via a support member 403, and the support member 403 may be an electrical insulator. In particular, the support member 403 may be a dielectric. Thus, the second structure 402 is electrically isolated from the first structure 401 via the support member 403.

[0098] The second structure 402 can be considered as including the body of the substrate, wherein the electrode arrangement 407 of the second structure 402 is disposed on the surface of the substrate.

[0099] A lens can be considered to include a first lens portion and a second lens portion. The first and second lens portions are respectively defined as including, for example... Figure 4 The first lens portion is located above and below the plane of the feed line shown. Therefore, the first lens portion is situated on one side of the plane orthogonal to the longitudinal axis of the opening, and substantially in the longitudinal direction of the feed line 408. The first lens portion may not include the feed line 408, may include at least a portion of the feed line 408, or may include all of the feed line 408. The second lens portion is located on the opposite side of the plane relative to the first lens portion. The second lens portion may not include the feed line 408, may include at least a portion of the feed line 408, or may include all of the feed line 408.

[0100] The method of manufacturing a lens is to manufacture the first and second lens portions of the lens separately, and then combine the first and second lens portions together to form the lens.

[0101] Each of the first and second lens portions can be substantially identical to each other. However, embodiments also include lens designs in which the first and second lens portions differ from each other. The lens portions can be asymmetrical upstream and downstream of the feed line. The lens can be asymmetrical with respect to its feed line 408.

[0102] The first and second parts can be fabricated in one of the multiple layers of a substrate using known semiconductor manufacturing processes.

[0103] The first and second lens portions can be combined using any of a variety of known techniques. Advantageously, as shown and described... Figure 4 A lens is provided having the geometry of the disclosed electrode arrangement 407 and support 403, which is configured and arranged to generate a rotationally symmetric electric field around the sub-beam path in operation.

[0104] Figure 5 A more detailed description or alternative implementation of the first lens portion according to the first embodiment is shown. According to... Figure 5 In the lens design, the substrate body 409 of the second structure 402 and the first structure 401 in the same plane as the second structure 402 can be made of the same one or more substrate layers as a first group of one or more substrate layers. The substrate element 410 of the first structure 401, which is in a different plane from the second structure 402, can be made of a second group of one or more substrate layers. The first surface 404 may include an electrode extending into the first structure 401 at the boundary between the first and second groups of layers. The substrate element 410 can provide the inlet electrode of the lens.

[0105] The second lens portion may be substantially identical to the first lens portion. The first and second lens portions may be on either side of the feed line. In one arrangement, the first and second lens portions may be substantially mirror images of each other around the feed line. The lens of this implementation according to the first embodiment can be manufactured by combining the first and second lens portions together. The second lens portion may be characterized by a corresponding substrate element 410, which is located in a different plane from the second structure 402 of the second lens portion. The substrate element 410 may include a substrate. The substrate element 410 of the second lens portion may have a first surface 404 that provides an electrode as an exit electrode of the lens during operation.

[0106] Figure 6This is a schematic plan view showing a cross-section of the lens according to the present implementation of the first embodiment. The cross-section is in a plane orthogonal to the longitudinal axis of the opening and at the feed line 408. Clearly, within the cross-section, the electrode arrangement 407 completely surrounds the opening. The second structure 402 surrounds the electrode arrangement 407. The support member 403 surrounds the second structure 402. The first structure 401 surrounds the support member 403.

[0107] The lens design according to this embodiment has many advantageous characteristics.

[0108] The electrode arrangement 407 on the first surface 404, the second surface 405, and the second structure 402 is rotationally uniform / symmetrical about the longitudinal axis. These are the main exposed surfaces of the lens, where charged particles in the opening are primarily affected. Therefore, charged particles passing through the opening of the lens are not inherently manipulated in an asymmetrical manner (due to the asymmetrical lens design).

[0109] The insulator providing the support 403 electrically insulates the second structure 402 from the first structure 401. In one arrangement, the first structure 401 may include a substrate body 409 and a substrate element 410. The support 403 can electrically insulate the second structure 402 from the substrate body 409 but mechanically connect it to the substrate body 409. A problem with using an insulator that may be dielectric is that charge may accumulate on the surface of the insulator. This can affect the path of charged particles through the lens.

[0110] Creep length can be defined as the distance on a separating surface (such as an insulating surface) between two electrode surfaces that are at a potential difference from each other. For the electrode surfaces to be electrically isolated from each other, they need to be separated by at least the minimum required creep length. If the electrode surfaces are not separated by at least the minimum required creep length, leakage current can flow from one electrode surface across the separating surface and to the other electrode surface. The minimum required creep length can depend on the potential difference between the electrode surfaces. Therefore, the actual creep length between adjacent electrode surfaces can limit the potential difference applied between the electrode surfaces. Thus, the creep length can determine the radial dimension of the support 403. The radial dimension of the gap between the second structure 402 and the substrate body 409 can be determined at least in part by the nature of the vacuum gap between the second structure 402 and the substrate body above the support 403. The vacuum gap has a different radial dimension requirement than the creep length. The vacuum gap is ideally sized radially such that the operating potential difference between the substrate body 409 and the second structure does not exceed the breakdown voltage or electric field. For a gap of a specific size, when the operating potential difference is higher than the breakdown voltage, there is a risk of discharge between the substrate body 409 and the second structure 402.

[0111] The lens design according to the embodiment can have a geometry that separates the surface of the electrodes (e.g., positions shown in 407 and 404) from a plurality of orthogonally aligned separation surfaces (e.g., horizontally and vertically aligned separation surfaces). Advantageously, this allows for a relatively long creep length between the surfaces of adjacent electrodes. Therefore, the creep length allows adjacent electrode surfaces to operate under a relatively large potential difference. Note that in Figure 4 and Figure 5 In the arrangement shown, the surface described only in terms of creep length requirements is the radial surface. This surface will be the surface of support 403, in which the vacuum gap extends between the second structure 402 and the substrate body 409.

[0112] The lens geometry according to the embodiment can also reduce the influence of the exposed surface of the insulator on charged particles passing through the opening. Since the longitudinal extent of the second structure 402 is greater than that of the support 403, the insulator essentially shields the electron beam passing through the opening. The second structure 402 can prevent the line-of-sight path of charged particles between the insulator and the opening. The second structure 402 has a greater longitudinal length than the insulating support 403.

[0113] The lens includes a feed line 408, which is located substantially at the longitudinal midpoint of the second structure 402. The connection of the feed line 408 to the electrode arrangement 407 completely surrounds the electrode arrangement 407. The feed line 408 is completely covered by the support member 403 and the second structure 402. This prevents the feed line 408 from directly affecting charged particles passing through the opening. Advantageously, this manner of providing the feed line 408 does not disrupt the axial symmetry of the structure surrounding the exposed surface of the lens.

[0114] The lens design is also compact and suitable for dense arrays of lenses, i.e., dense lens arrays. Such lenses can share a common substrate, allowing the array to be included within multiple substrates, for example, as layers. Therefore, more lenses can be used to fill a lens array of a given size. The bundle arrangement can have a dense encapsulation structure, such as a hexagonal dense package. The spacing between lenses in the array can be smaller than the spacing in known lens designs.

[0115] The lens array comprises multiple lenses. Each lens in the array can be arranged to focus different sub-beams from multiple beams of charged particles. The longitudinal axes of all lens openings in the array can be substantially parallel to each other. All sub-beams in the multiple beams can be collimated, and the path of each sub-beam is along or parallel to the longitudinal axis of the opening. However, embodiments also include sub-beams within the multiple beams being divergent or convergent, and some or all of the paths of the sub-beams forming an angle relative to the longitudinal axis of the respective opening.

[0116] One or more layers of all lenses in a lens array can be formed in the same corresponding substrate layer.

[0117] Figure 7 A cross-section of the lens array is shown. Figure 7 Two lenses are shown in a lens array, each of which is a lens according to a first embodiment. The cross-section is in a plane that includes the path of a charged particle through the lens. The lens design allows for a relatively small spacing (i.e., interval) between adjacent lenses. Therefore, a dense lens array can be provided.

[0118] The opening of each lens in the array is completely surrounded or even encircled by a portion of the first structure 401, such that each lens in the array is separated from all adjacent lenses in the array by a portion of the first structure 401 in which the lens opening is formed. Advantageously, this substantially reduces or prevents potential crosstalk between adjacent sub-bundles.

[0119] The electrode arrangement 407 can be made of, for example, gold. The advantage of using gold is that it is easy to sputter and does not oxidize in air.

[0120] The second structure 402 can be made of, for example, silicon, silicon carbide, germanium, other group IV semiconductors or other known substrate materials.

[0121] The support 403 can be made of, for example, silicon dioxide or any other insulating material.

[0122] The first structure 401 may be made of, for example, silicon, silicon carbide, germanium, other group IV semiconductors or other known substrate materials.

[0123] Feeder 408 can be made of, for example, aluminum.

[0124] exist Figure 7 In this embodiment, dimension 'a' can be approximately 30 μm. Dimension 'a' corresponds to the dimension of the first gap in the beam path direction. Dimension 'a' can also correspond to the radial width of the support in a plane orthogonal to the beam path; however, the radial width of the support can also be different. Dimension 'b' (i.e., the width of the second structure 402 in a plane orthogonal to the charged particle beam path) can be approximately 10 to 15 μm. Dimension 'c' is the width or diameter of the opening, which can be approximately 140 μm. Dimension 'd' is the shortest separation between adjacent lenses, which can be approximately 15 μm; and dimension 'w' is the thickness of the substrate. This can be approximately 250 μm to 300 μm. All substrates can have the same thickness. Alternatively, some of the substrates can have different thicknesses.

[0125] The dimensions provided above are approximate, and embodiments may include dimensions within ±20% or greater of the values ​​provided above. Minimum values ​​for dimensions 'b' and 'd' may be constrained by manufacturing process limitations. Dimension 'c' may be limited by lens performance requirements. Generally, reducing 'c' below a certain value will result in increased aberrations. Minimum values ​​for dimension 'a' may be constrained by lens operational requirements, such as minimizing creep length and / or minimizing size to avoid flashover. For example, if the first gap needs to withstand a potential difference of 1000V, the minimum value of dimension 'a' may be 45μm. However, if the first gap needs to withstand a potential difference of 100V, the minimum value of dimension 'a' may be 3μm, where the value of dimension 'a' is limited by vacuum flashover.

[0126] The spacing between adjacent lenses is the separation between the longitudinal axes of the opening in the plane of each lens, which can be orthogonal to the intended beam path. The dimensional contributions to the spacing include a, b, and c. The electrode arrangement of each adjacent lens and its associated insulation contribute to the spacing. Therefore, when determining the spacing, dimensional contributions a and b should be considered twice. In one embodiment, the minimum spacing is within the following range:

[0127] p = 2a + 2b + c + d = approximately 235 μm to 245 μm.

[0128] Figure 8 Another lens array including a lens according to a second embodiment is shown. The design of the lens according to the second embodiment differs from that according to the first embodiment in that, when the lens according to the second embodiment is formed in the lens array, the opening of each lens is not completely surrounded by a portion of the first structure 401. For adjacent lenses in the lens array, a first gap between each lens is formed by a first channel 801. The first channel 801 extends between adjacent lenses within the first structure 401 and is substantially orthogonal to the lens axis. The first channel 801 may have an upper channel surface 803 and a lower channel surface. The lower channel surface may face the upper channel surface 803. The lower channel surface may include a radial surface of the second structure 402, which may include a radially coated portion 805 of an adjacent electrode and an uncoated radial portion 807 of an adjacent radially coated portion 805. Between the adjacent electrodes is a support surface 808, which is a support surface facing the upper channel surface 803. The upper channel surface 803 may extend through the channel between the lenses such that the first surface 404 of each adjacent lens has a common potential applied in operation. However, the electrode arrangements 407 on the second structure 402 of each adjacent lens can be electrically isolated from each other.

[0129] Similarly, for the adjacent lenses in the lens array, the second gap between each lens can be formed by a second channel 802 extending within a first structure 401 between adjacent lenses. The second channel 802 extends between adjacent lenses within the first structure 401 and is substantially orthogonal to the lens axis. The second channel 802 may have an upper channel surface and a lower channel surface 804. The lower channel surface 804 may extend through the channel between the lenses such that the second surface 405 of each adjacent lens has a common potential applied during operation.

[0130] In all other respects of the above differences, the lens design of the second embodiment may be substantially the same as that of the lens design of the first embodiment.

[0131] Despite Figure 8 Not shown in the diagram, but the lens array may also include protrusions in the first structure 401 between adjacent lenses, such that the first and second channels are not linear and / or their channel widths decrease by the protrusions. The protrusions may be substantially as described in the reference later. Figure 11 As described, and shown therein by reference numerals 1111 and 1113.

[0132] The advantage of a lens array including the lens according to the second embodiment is that the spacing between adjacent lenses in the lens array can be smaller than the spacing of a lens array including the lens according to the first embodiment. Therefore, the lens array can be more densely packed.

[0133] The dimensions of the lens design can be basically as follows Figure 7 As shown. However, due to the lens design of the second embodiment, the spacing p can be reduced to:

[0134] p = a + 2b + c = approximately 190 μm to 200 μm.

[0135] Figure 9 A lens design according to a third embodiment is shown. The lens design according to the third embodiment differs from the lens design of the first embodiment in that the structure corresponding to the support member 403 of the second structure 402 is not an insulator.

[0136] exist Figure 9 In this structure, the structure corresponding to the support member 403 is the support portion 905. The structure corresponding to the second structure 402 is the electrode portion 903. The first structure 401, the support portion 905, and the electrode portion 903 can all be integrated with each other to provide an integrated structure. All of the first structure 401, the support portion 905, and the electrode portion 903 can substantially comprise a substrate. The electrode portion 903 also includes one or more electrical insulating layers 901 and one or more electrode arrangements 407.

[0137] The lens design according to the third embodiment is similar to the lens designs of the first and second embodiments, because the overall structure can be a single-lens overall structure.

[0138] Electrode portion 903 includes an end surface extending in a direction orthogonal to the longitudinal axis. End surface 911 and facing surface 919 of first structure 401 partially define a first gap. Electrode arrangement 407 is disposed on radially inward surface 909 of electrode portion 903. Electrode portion 903 has radially outward surface 913.

[0139] The support portion 905 extends radially outward from the electrode portion 903 and has a facing surface 915 that faces the facing surface 919 of the first structure 401. The facing surface 915 of the support portion 905 is further away from the facing surface 919 of the first structure 401 than the end surface 911.

[0140] The radially outer side of the support portion 905 is the connecting portion 907, which connects the support portion 905 to the first structure 401 within the integrated structure. The connecting portion 907 has a radially inward surface 917 facing the radially outward surface 913 of the electrode portion 903. The portion of the connecting portion 907 adjacent to the first structure may be referred to as a rod.

[0141] Electrode portion 903 includes an electrically insulating layer 901 on one or more of its surfaces. Electrode arrangement 407 of electrode portion 903 is disposed on electrically insulating layer 901. Electrode arrangement 407 of electrode portion 903 is thus electrically insulated from the portion of electrode portion 903 integrated with support portion 905, which can be at ground potential.

[0142] An electrical insulating layer 901 may be provided on the radially inward surface 909 of the electrode portion 903. The electrical insulating layer 901 may also be provided on the end surface 911 of the electrode portion 903 in a direction orthogonal to the longitudinal axis of the opening. The electrical insulating layer 901 may additionally be provided on the radially outward surface 913 of the electrode portion 903.

[0143] As referenced above Figure 4 As described, a lens can be considered to include a first lens portion and a second lens portion. The first and second lens portions of the lens are respectively defined as including, for example... Figure 9 The first lens portion is located above and below the plane of the feed line shown. Therefore, the first lens portion is situated on one side of a plane orthogonal to the longitudinal axis of the opening and is substantially longitudinally positioned relative to the feed line. The first lens portion may not include the feed line, may include at least a portion of the feed line, or may include all of the feed line. The second lens portion is located on the opposite side of the plane of the first lens portion. The second lens portion may not include the feed line, may include at least a portion of the feed line, or may include all of the feed line.

[0144] The electrical insulating layer 901 can also extend into the lens along the lower surface of the first lens portion or within the first lens portion in a direction orthogonal to the longitudinal axis of the opening, such that the electrical insulating layer 901 is above the feed line. The electrical insulating layer 901 can also extend into the lens along the upper surface of the second lens portion or within the second lens portion in a direction orthogonal to the longitudinal axis of the opening, such that the electrical insulating layer 901 is below the feed line. Figure 9 As shown, each of the upper and lower surfaces of the feed line can thus be electrically isolated from the rest of the lens via the electrical insulating layer 901.

[0145] The first and second lens sections have a corresponding arrangement. Therefore, the lenses can be substantially symmetrical about the plane including the feed line.

[0146] In all other respects of the above differences, the lens design of the third embodiment may be substantially the same as that of the lens design of the first embodiment.

[0147] One effect of the structural difference in lens design between the first and third embodiments is that the insulator shields the electron beam passing through the opening in different ways. In the third embodiment, the exposed surface of the electrical insulating layer 901 extends longitudinally rather than horizontally. The exposed surface of the electrical insulating layer 901 is on the side of the electrode portion 903 opposite to the radially inward surface 909. Therefore, there is no line-of-sight path between the charged particles passing through the opening and the exposed surface of the electrical insulating layer 901.

[0148] The geometry of the components in the lens structure that define the creep length also differs. The facing surface 915 of the support portion 905 can be at ground potential. The creep length will include the entire length of the exposed surface of the electrical insulating layer 901 along the radially outward surface 913 of the electrode portion 903.

[0149] Figure 10 A cross-section of a lens array including a lens according to a third embodiment is shown. Figure 10 Two lenses of a lens array are shown, each of which is a lens according to a third embodiment. The cross-section is in a plane that includes the path of a charged particle through the lens. The lens design allows for relatively small spacing (i.e., interval) between adjacent lenses, thus providing a dense lens array.

[0150] The opening of each lens in the array is completely surrounded by a portion of the first structure 401, such that each lens in the array is separated from all adjacent lenses in the array by a portion of the first structure 401 in which the lens opening is formed. Advantageously, this can substantially reduce or even prevent potential crosstalk between adjacent sub-bundles.

[0151] exist Figure 10The image shows various dimensions of the elements of the lens array in a plane orthogonal to the central axis. Dimension 'bx' is the width of the connecting portion 907. Dimension bx can be approximately 10 μm. Dimension 'dx' is the diameter of the lens between opposing radially inward surfaces 909; it can be approximately 140 μm. Dimension 'ex' is the radial width of the electrode portion 903; it can be approximately 5 μm. Dimension 'gx' is the radial width of the support portion 905; it can be approximately 30 μm. The spacing px between adjacent lenses in the array depends on the dimension elements: dx, ex, gx, and bx. In one embodiment, the minimum spacing between adjacent lenses is within the following range:

[0152] px =dx+2ex+2gx+bx =about 220μm

[0153] Figure 11 Another lens array including a lens according to a fourth embodiment is shown. The design of the lens according to the fourth embodiment differs from that according to the third embodiment in that, when the lens according to the fourth embodiment is formed in the lens array, the opening of each lens is not completely surrounded by a portion of the first structure 401 (i.e., the connecting portion 907). In the fourth embodiment, channels 1101, 1102 are provided between adjacent lenses in a manner similar to that described above for the second embodiment. Therefore, for adjacent lenses in the lens array, a first gap between each lens is formed by a first channel 1101 extending within the first structure 401 between adjacent lenses. Similarly, for the adjacent lenses in the lens array, a second gap between each lens is formed by a second channel 1102 extending within the first structure 401 between adjacent lenses.

[0154] In all other respects of the above differences, the lens design of the fourth embodiment may be substantially the same as that of the lens design of the third embodiment.

[0155] like Figure 11 As shown, between each adjacent lens pair, the first structure 401 may include a first set of protrusions 1111, each protrusion 1111 extending in a direction parallel to the longitudinal axis of the opening, such that the protrusion 1111 blocks the linear path of the first channel 1101 between the first gaps of the adjacent lenses. Each protrusion 1111 may be associated with the channel 1101 between the adjacent lenses. The stem of each protrusion may have the same features as a portion of the stem of the connecting portion 907. However, unlike the connecting portion 907, for each protrusion, the radially inward surface 917 terminates at an engagement of an end surface orthogonal to the longitudinal axis of the opening. Therefore, the radially inward surface 917 is sized such that it extends from the first portion and blocks the linear path between the first gaps of the adjacent lenses. A portion of the radially inward surface 917 may face a portion of the radially outward surface 913 of the electrode portion 903.

[0156] Similarly, between each adjacent lens pair, the first structure 401 includes a second set of protrusions 1113 extending between adjacent lenses in a direction parallel to the longitudinal axis of the opening, such that each protrusion in the second set can block the linear path of the second channel 1102 between the second gaps of the adjacent lenses. Similar features associated with the first set of protrusions 1111 apply to the second set of protrusions 1113.

[0157] The protrusions in the first group of protrusions 1111 and the second group of protrusions 1113 can be at the same potential as the first surface 404 and the second surface 405, respectively. Therefore, the protrusions can be grounded.

[0158] In an alternative implementation of the fourth embodiment, there are no protrusions in the first and second channels. The first and second channels can be substantially linear, such as... Figure 8 The channel shown.

[0159] The advantage of a lens array including the lens according to the fourth embodiment is that the spacing between adjacent lenses in the lens array can be smaller than the spacing of a lens array including the lens according to the third embodiment. Therefore, the lens array can be more densely packed.

[0160] The dimensions of the lens design can be basically as follows Figure 10 As shown. However, due to the lens design of the fourth embodiment, the size 'bx' can be reduced to 10 μm. Therefore, the spacing px can thus be reduced to:

[0161] px = dx + 2ex + 2gx + bx = approximately 215μm.

[0162] The lens design according to this embodiment has many advantageous characteristics.

[0163] All embodiments of the lens offer one or more of a number of different advantages. In particular, the exposed surface of each lens (i.e., the lens surface that a charged particle in the opening may come into contact with) is rotationally uniform / symmetrical about the longitudinal axis. Therefore, charged particles passing through the lens opening are not inherently manipulated in an asymmetrical manner (due to the asymmetrical lens design).

[0164] The structure of each lens design essentially shields the exposed surface of the insulator from the electron beam passing through the opening.

[0165] The feed line 408 of each lens is covered by at least a portion of the support 403 and the second structure 402, so that it does not directly affect charged particles and does not disrupt the symmetry of the exposed surface of the lens.

[0166] The lens design according to the embodiment can have a long creep length. This can be achieved by a creep length that is oriented at least partially parallel to the beam path or has a component extending in the direction of the beam path. This allows for the use of a relatively large potential difference between adjacent electrodes. Orienting the creep length at least partially in the direction of the beam path allows for a reduction in some of the dimensions of the lens design, thereby reducing the spacing between adjacent lenses.

[0167] Each lens can be manufactured by separately making two parts of the lens and then joining the two parts together.

[0168] The lens design is also compact and suitable for dense arrays of lenses, i.e., dense lens arrays. The lens array according to the embodiment can be used to focus all sub-beams in a multi-beam configuration.

[0169] The embodiments include many modifications and variations to the above embodiments.

[0170] Although the embodiments have been described as providing lens designs, lenses can generally be referred to as manipulators because they can be used to manipulate beams or sub-beams of charged particles. A possible application of the lens or lens array according to the embodiments is the focusing of beams or sub-beams of charged particles. The charged particles can be electrons. Alternative applications according to the embodiments include defocusing, accelerating, or decelerating beams or sub-beams of charged particles.

[0171] The embodiments have been described with reference to charged particles. Charged particles can be electrons or other types of charged particles, such as protons.

[0172] The tool, which includes a lens or lens array according to the embodiments, can be used in many different applications, which typically include electron microscopy, not just SEM and photolithography.

[0173] For example, embodiments include multi-beam inspection and / or measurement tools that include a lens array according to embodiments.

[0174] The lens according to the embodiment can be manufactured using a variety of techniques known to those skilled in the art of semiconductor manufacturing processes. Specifically, the manufacturing process may include one or more of the following processes known to those skilled in the art: oxidation, photolithography, etching, trench filling, planarization, Me (e.g., gold) deposition, Me sputtering, and bonding.

[0175] Each lens according to an embodiment may include four or more substrate groups. The substrate groups may be manufactured separately and then joined together to form the lens. For example, as... Figure 5The first lens portion of the illustrated lens may include a first set of one or more substrates providing electrode arrangement 407, second structure 402, support 403, and a substrate on the other side of support 403, different from the second structure 402. The first lens portion may also include a second set of one or more substrates providing the first structure and first surface 404. The second lens portion of the lens may be substantially a mirror image of the first lens portion with respect to a plane including the feed line. Therefore, the second lens portion also includes two sets of substrates. Thus, the lens includes four sets of substrates bonded together to form the lens. In another arrangement, three sets of substrates are present. The first set of at least two substrates forms electrode arrangement 407, support 403, and substrate body 409 on either side of the closed feed line 408. The second set of at least one substrate provides a structure for an inlet electrode. The third set of at least one substrate provides a structure for an outlet electrode. The second and third sets may be assembled with the first set after the first set is assembled. Alternatively, the second and third sets may be bonded to the substrates of the first set before the first set is assembled.

[0176] Each lens according to an embodiment may be constructed from a substrate stack. The stack may include other elements besides each lens along the same charged particle path as the lens. For example, the stack may include one or more deflector elements upstream and / or downstream of the lens along the charged particle path. Spacers may be provided on the upstream and / or downstream side of each lens. Each spacer may separate the lens from another element along the same charged particle path as the lens. Each spacer may be incorporated into the fully manufactured lens. Alternatively, spacers may be incorporated into each of the first and second lens portions of the lens before the first and second lens portions of the lens are incorporated. Inlet and outlet electrodes may be considered as spacer elements.

[0177] Figure 5 The features of the first set of substrates for the first lens portion of the lens shown can be fabricated in a variety of different ways. For example, two trenches can be formed in the substrate at the location of the support 403 on either side of the opening for charged particles. The trenches can be filled with oxide. A third trench can then be formed between the two filled trenches, providing the opening for charged particles and also forming a second structure 402 on the opening side of each filled trench. A process can then be performed to reduce the longitudinal length of the oxide in the trenches, such that the oxide corresponds to, as Figure 5 The support member 403 is shown. A conductive layer can then be formed on its surface, such as... Figure 5 As shown.

[0178] The lens according to the embodiment preferably includes rotationally symmetric electrodes (preferably circular rotationally symmetric electrodes). If the electrodes are not rotationally symmetric, this may increase the degree of aberration in the charged particle beam passing through the lens. Although the support structure of the electrodes can be rotationally symmetric, this is not necessary. If the support structure of the electrodes is not rotationally symmetric, the aberration may not increase significantly if the support structure shields the charged particle beam through the electrodes. In one arrangement, the support is cylindrical, such that it has circular rotational symmetry relative to the sub-beam path. In this arrangement of the support, the rotationally symmetric support is a plurality of (preferably equidistant) longitudinal elements surrounding the periphery of the focusing electrode; two, three, four or more equidistant longitudinal support elements may be present.

[0179] In one configuration, Figure 4 , 5 The electrode elements of 7 and 8 may be conductive doped silicon. Instead of being coated, the first structure 401 and the second structure 402 may include a doped substrate.

[0180] The embodiments include many modifications and variations of the above-described techniques.

[0181] Throughout this embodiment, the longitudinal axis of the opening is described. This axis may be the same as the charged particle optical axis, which describes the path of charged particles through and from the irradiation and / or projection device. Sub-beams in a multi-beam configuration may all be substantially parallel to the charged particle optical axis. The charged particle optical axis may be the same as or different from the mechanical axis of the irradiation and / or projection device.

[0182] According to embodiments that are angled relative to the longitudinal axis of each opening, the embodiments also include the beam path of charged particles through each of the lenses or multiple lenses in an array. That is, the beam path through each lens is not along or parallel to the longitudinal axis of the lens. For example, the multiple lenses in the lens array may each be arranged to manipulate corresponding sub-beams in a multi-beam array, the sub-beams within the multi-beam array diverging or converging relative to each other.

[0183] The technique according to the embodiments can be used to construct a single lens. However, the embodiments also include the construction of other types of manipulators, such as manipulators with only two electrodes. For example, the embodiments include... Figure 5 The entire actuator shown comprises only the electrode arrangement 407, the second structure 402, the support 403, and the substrate body 409 of the second lens portion. That is, the substrate element 410 providing the exit electrode in the second lens portion can be omitted. In this arrangement, the lens arrangement may include three substrates: one substrate for the substrate element 410 of the first lens portion; and one substrate for each of the second structures 402 in each of the first and second lens portions.

[0184] The embodiments include a multi-array single lens configured to focus multiple charged particle sub-beams along a multi-beam path in use, wherein each single lens in the array includes a focusing electrode located midway between upstream and downstream electrodes along the beam path and configured to be at a different potential than the upstream and downstream electrodes. The focusing electrode is electrically isolated from the upstream and downstream electrodes. The focusing electrode may include an electrode surface and a support. The support may be substantially symmetrical about the beam path, configured to support the electrode surface in a plane orthogonal to the beam path, and configured to electrically connect to the electrode surface.

[0185] The embodiments include a multi-array single lens configured to focus multiple charged particle sub-beams along a multi-beam path in use, wherein each single lens in the array includes a focusing electrode located between upstream and downstream electrodes and configured to be isolated from and at a different potential than the upstream and downstream electrodes. The focusing electrode may extend along the beam path and substantially symmetrically around the beam path. Each single lens may include a support configured to support the focusing electrode. The focusing electrode may extend further along the beam path than the support, such that the dimensional difference between the support and the focusing electrode along the beam path provides a creep length parallel to the beam path.

[0186] The embodiment includes a multi-array lens configured to focus multiple charged particle sub-beams along a multi-beam path during use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential than the inlet electrode during operation; and a support for supporting and electrically isolating the focusing electrode. The focusing electrode may be substantially rotationally symmetric about the sub-beam path. Each lens in the array may also include an outlet electrode. The focusing electrode may be upstream of the outlet electrode along the sub-beam path and configured to be at a different potential than the outlet electrode during operation.

[0187] The embodiment includes a multi-array lens configured to focus multiple charged particle sub-beams along a multi-beam path during use, wherein each lens in the array includes: an inlet electrode; and a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential than the inlet electrode. The focusing electrode may include an electrode surface and a support. The support may be symmetrical about the sub-beam path, configured to support the electrode surface in a plane orthogonal to the beam path, configured to electrically isolate the focusing electrode from the inlet electrode, and configured to connect the electrode surface to a feed line. Each lens in the array may also include an outlet electrode. The focusing electrode may be upstream of the outlet electrode along the sub-beam path and configured to be at a different potential than the outlet electrode during operation.

[0188] The embodiments include a multi-array single lens configured to focus multiple charged particle sub-beams along a multi-beam path in use, wherein each single lens in the array includes a focusing electrode located between upstream and downstream electrodes and configured to be isolated from and at a different potential than the upstream and downstream electrodes. The focusing electrode may extend along the beam path and substantially symmetrically around the beam path. Each lens may include a support configured to support the focusing electrode. The focusing electrode may extend further along the sub-beam path than the support, such that a dimensional difference between the support and the focusing electrode along the beam path provides shielding of the support to the beam path. Shielding may be provided by the radial position of the focusing electrode relative to the support.

[0189] The following is an overview of the embodiments of the present invention.

[0190] According to a first aspect of the invention, a manipulator lens device for focusing a charged particle beam is provided, wherein the manipulator lens device comprises: a first structure through which an opening is formed, wherein the path of the charged particle beam through the manipulator lens device is substantially along the longitudinal axis of the opening; a second structure having a surface, wherein the surface surrounds the opening in a plane orthogonal to and along the longitudinal axis for a first portion; a support member, wherein at least a portion of the support member in a plane orthogonal to and along the longitudinal axis for a first portion connects the second structure to the first structure and surrounds the second structure, such that the connection between the second structure and the first structure is symmetrical about the longitudinal axis; and an electrode arrangement disposed on the surface of the second structure, such that the electrode arrangement surrounds the longitudinal axis of the opening and is orthogonal to the longitudinal axis. In the plane, the surface of the second structure surrounds the electrode arrangement; wherein: the first surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a second portion of the longitudinal axis of the opening, the first surface surrounds the opening; the second surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a third portion of the longitudinal axis, the second surface surrounds the opening; the surface of the second structure is arranged between the first surface and the second surface of the first structure along the longitudinal axis; the electrode arrangement is separated from the first surface of the first structure in a direction parallel to the longitudinal axis, such that a first gap exists between the electrode arrangement and the first surface of the first structure; and the electrode arrangement is separated from the second surface of the first structure in a direction parallel to the longitudinal axis, such that a second gap exists between the electrode arrangement and the second surface of the first structure.

[0191] Preferably: the surface of the second structure completely surrounds the opening; the support completely surrounds the second structure; the first surface of the first structure completely surrounds the opening; the second surface of the first structure completely surrounds the opening; and / or the electrode arrangement completely surrounds the opening.

[0192] Preferably, the electrode arrangement is a single electrode.

[0193] Preferably, the opening is circular in a plane orthogonal to the longitudinal axis.

[0194] Preferably, in a plane orthogonal to the longitudinal axis, the radius of the opening is greater at the first and second gaps than at the first and second portions of the longitudinal axis.

[0195] Preferably, the electrode arrangement is annular in a plane orthogonal to the longitudinal axis.

[0196] Preferably, the second structure is annular in a plane orthogonal to the longitudinal axis.

[0197] Preferably, the support is annular in a plane orthogonal to the longitudinal axis.

[0198] Preferably, along the longitudinal axis, the extent of the support member is smaller than the extent of the surface of the second structure.

[0199] Preferably, the longitudinal midpoint of the support member and the longitudinal midpoint of the surface of the second structure are in the same plane.

[0200] Preferably, the manipulator lens device further includes a feed line, wherein the feed line is electrically connected to the electrode arrangement.

[0201] Preferably, the feeder passes through the support and enters the second structure.

[0202] Preferably, the feeder is electrically connected to the electrode arrangement at the longitudinal midpoint of the electrode arrangement.

[0203] Preferably, the electrode arrangement is surrounded by the feed line in a plane orthogonal to the longitudinal axis.

[0204] Preferably, the first electrode is arranged in at least one plane orthogonal to the longitudinal axis and extends at least one end of the second structure.

[0205] Preferably, the manipulator lens assembly is symmetrical about the longitudinal axis.

[0206] Preferably, the charged particle is an electron.

[0207] Preferably, the manipulator lens device includes a first part and a second part; and the first part of the manipulator lens device is combined with the second part of the manipulator lens device.

[0208] Preferably, a plane located substantially in the longitudinal direction of the feed line and orthogonal to the longitudinal axis provides the boundary between the first and second portions.

[0209] Preferably, the second part of the manipulator lens device is a fundamental mirror image of the first part of the manipulator lens device.

[0210] Preferably: the first part of the manipulator lens device includes a first part of a first structure; the second part of the manipulator lens device includes a second part of the first structure; the first part of the first structure is a single-layer substrate; the second part of the first structure is a single-layer substrate.

[0211] Preferably, the first surface of the first structure and the second surface of the first structure are at the same potential; and optionally, the potential is a ground potential.

[0212] Preferably, the support is an electrical insulator, such as a dielectric.

[0213] Preferably, the second structure is connected only to the electrical insulator.

[0214] Preferably, the second structure includes a substrate; and the electrodes are arranged on the surface of the substrate.

[0215] Preferably, the second structure is configured such that, in use, the electrical insulator is shielded from the charged particle beam.

[0216] Preferably: the support includes a substrate; the second structure includes a substrate; the second structure includes an electrically insulating layer, such as a dielectric, on the substrate; and the electrode arrangement is disposed on the electrically insulating layer.

[0217] According to a second aspect of the invention, a manipulator lens array is provided, the manipulator lens array comprising a plurality of manipulator lens devices according to the first aspect; wherein the openings of all manipulator lens devices are formed by the same first structure.

[0218] Preferably, the longitudinal axes of all the openings of the manipulator lens assembly are substantially parallel to each other.

[0219] Preferably, each manipulator device in the manipulator array is configured to focus different sub-beams in the multi-beam array.

[0220] Preferably, the opening of each manipulator lens device is completely surrounded by a portion of the first structure, such that each manipulator lens device is separated from all adjacent manipulator lens devices by the portion of the first structure in which the opening is formed.

[0221] Preferably, for adjacent manipulator lens devices: a first gap in each manipulator lens device is formed by a first channel extending within a first structure between the manipulator lens devices; between each pair of adjacent manipulator lens devices, the first structure includes a first set of protrusions extending parallel to a longitudinal axis, such that protrusions in the first set of protrusions block the linear path of the first channel between the first gaps of the adjacent manipulator lens devices; a second gap in each manipulator lens device is formed by a second channel extending within a substantially planar structure between the manipulator lens devices; and between each pair of adjacent manipulator lens devices, the first structure includes a second set of protrusions extending parallel to a longitudinal direction between the adjacent manipulator lens devices, such that protrusions in the second set of protrusions block the linear path of the second channel between the second gaps of the adjacent manipulator lens devices.

[0222] Preferably, at least some of the protrusions in the first group and / or the second group are grounded.

[0223] According to a third aspect of the invention, a method is provided for incorporating a first portion of a manipulator lens assembly into a second portion of the manipulator lens assembly.

[0224] According to a fourth aspect of the invention, a single lens is provided for focusing a charged particle beam, wherein the single lens includes: a focusing electrode arrangement to which a voltage for focusing the charged particle beam is applied; a first electrode arrangement on a body of the single lens; and a second electrode arrangement on a body of the single lens, wherein the focusing electrode arrangement is arranged between a first and a second ground electrode arrangement along a longitudinal axis of the single lens, and the focusing electrode arrangement is electrically isolated from the first and second ground electrode arrangements; wherein the focusing electrode arrangement includes: a structure on which one or more electrodes are formed; and a support member that mechanically connects the structure to the body of the single lens in a plane orthogonal to the longitudinal axis by a connection symmetrical about the longitudinal axis.

[0225] Preferably, the single lens further includes a feed line that enters the structure via a support in a plane orthogonal to the longitudinal axis and is electrically connected to one or more electrodes arranged in a focusing configuration.

[0226] Preferably, the first electrode arrangement and the second electrode arrangement are at the same potential; and optionally, the potential is a ground potential.

[0227] Preferably, the single lens includes: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be at a second potential; and a second electrode configured to be substantially at the first potential; the electrodes are arranged along a beam path such that the focusing electrode is between the first and second electrodes; wherein: the focusing electrode is electrically isolated from the first and second electrodes, the focusing electrode including: an electrode surface; and a support member symmetrical about the beam path and configured to support and electrically connect the electrode surface in a plane orthogonal to the beam path.

[0228] Preferably, the support includes a feed line configured to pass through the support and be electrically connected to the electrode surface.

[0229] Preferably, the feeder passes through the support in a plane orthogonal to the longitudinal axis.

[0230] According to a fifth aspect of the invention, a single lens is provided, configured to focus a beam of charged particles in a beam path during use, wherein the single lens comprises: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be disposed at a second potential, the focusing electrode extending along and symmetrically around the beam path; a second electrode configured to be disposed substantially at the first potential; and a support member configured to support the focusing electrode, wherein the focusing electrode is configured to be electrically isolated from the first and second electrodes, and the focusing electrode extends further along the beam path than the support member, such that a dimensional difference along the beam path between the support member and the focusing electrode provides a creep length parallel to the beam path.

[0231] According to a sixth aspect of the invention, a single lens is provided, configured to focus a charged particle beam in a beam path during use, wherein the single lens includes: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be at a second potential, wherein the focusing electrode extends along and symmetrically around the beam path, and the focusing electrode includes an electrode surface on a structure; a second electrode configured to be substantially at the first potential; and a support member configured to support the focusing electrode, the electrode being arranged along the beam path such that the focusing electrode is between the first and second electrodes, wherein the focusing electrode is configured to be electrically isolated from the first and second electrodes.

[0232] Preferably, the support is an electrical insulator.

[0233] Preferably, the structure is connected only to the electrical insulator.

[0234] Preferably, the structure includes a substrate; and one or more electrodes are on the surface of the substrate.

[0235] Preferably, the structure is configured such that, in use, the electrical insulator is shielded from the beam of charged particles focused by the single lens.

[0236] Preferably: the support includes a substrate; the structure includes a substrate; the structure includes an electrically insulating layer on the substrate; and one or more electrodes are disposed on the electrically insulating layer.

[0237] Preferably, the longitudinal extent of the structure along the longitudinal axis of the single lens is longer than the longitudinal extent of the support; and the structure and the support are arranged such that increasing the longitudinal extent of the structure relative to the longitudinal extent of the support increases the creep length of the focusing electrode arrangement.

[0238] According to a seventh aspect of the invention, a multi-array single lens is provided, configured in use to focus a plurality of charged particle sub-beams along a multi-beam path, wherein each single lens in the array includes: a focusing electrode located midway between an upstream electrode and a downstream electrode along the beam path and configured to be at a different potential from the upstream and downstream electrodes, wherein the focusing electrode is electrically isolated from the upstream and downstream electrodes; wherein the focusing electrode includes: an electrode surface; and a support member; wherein the support member is substantially symmetrical about the beam path; configured to support the electrode surface in a plane orthogonal to the beam path; and configured to be electrically connected to the electrode surface.

[0239] According to an eighth aspect of the invention, a multi-array single lens is provided, configured in use to focus a plurality of charged particle sub-beams along a multi-beam path, wherein each single lens in the array includes: a focusing electrode located between an upstream electrode and a downstream electrode and configured to be isolated from and at a different potential from the upstream and downstream electrodes, the focusing electrode extending along and substantially symmetrically around the beam path; and a support member configured to support the focusing electrode; wherein the focusing electrode extends further along the beam path than the support member, such that the dimensional difference between the support member and the focusing electrode along the beam path provides a creep length parallel to the beam path.

[0240] According to a ninth aspect of the invention, a multi-array lens is provided, configured to focus a plurality of charged particle sub-beams along a multi-beam path during use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential from the inlet electrode during operation; and a support for supporting and electrically isolating the focusing electrode, wherein the focusing electrode is substantially rotationally symmetric about the sub-beam path.

[0241] Preferably, each lens in the array further includes an exit electrode; wherein the focusing electrode is upstream of the exit electrode along the sub-beam path and is configured to be at a different potential from the exit electrode during operation.

[0242] According to a tenth aspect of the invention, a multi-array lens is provided, configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential than the inlet electrode, wherein the focusing electrode includes: an electrode surface; and a support member; wherein the support member is symmetrical about the sub-beam path; configured to support the electrode surface in a plane orthogonal to the beam path; configured to electrically isolate the focusing electrode from the inlet electrode; and configured to electrically connect the electrode surface.

[0243] Preferably, each lens in the array further includes an exit electrode; wherein the focusing electrode is upstream of the exit electrode along the sub-beam path and is configured to be at a different potential from the exit electrode during operation.

[0244] According to an eleventh aspect of the invention, a multi-array single lens is provided, configured in use to focus a plurality of charged particle sub-beams along a multi-beam path, wherein each single lens in the array includes: a focusing electrode located between upstream and downstream electrodes and configured to be isolated from and at a different potential from the upstream and downstream electrodes, wherein the focusing electrode extends along and substantially symmetrically around the beam path; and a support member configured to support the focusing electrode; wherein the focusing electrode extends further along the sub-beam path than the support member, such that the dimensional difference between the support member and the focusing electrode along the beam path provides shielding of the beam path by the support member.

[0245] Preferably, shielding is provided by the radial position of the focusing electrode relative to the support.

[0246] According to a twelfth aspect of the invention, a multi-array lens is provided, configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential from the inlet electrode; and a support member configured to support the focusing electrode relative to the inlet electrode, wherein the focusing electrode and the support member are configured such that the lens generates a rotationally symmetric field about the sub-beam path in operation.

[0247] While the invention has been described in conjunction with various embodiments, other embodiments of the invention will be apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the appended claims.

[0248] The above description is intended to illustrate and not limit. Therefore, it will be apparent to those skilled in the art that modifications as described can be made without departing from the scope of the claims set forth below.

[0249] In embodiments, the invention may be provided by the following terms:

[0250] Clause 1: A manipulator lens device for focusing a beam of charged particles, wherein the manipulator lens device comprises:

[0251] A first structure forms an opening through which the path of the charged particle beam through the manipulator lens device is substantially along the longitudinal axis of the opening.

[0252] A second structure having a surface, wherein the surface surrounds the opening in a plane orthogonal to the longitudinal axis and along the first portion of the longitudinal axis;

[0253] A support member, which connects and surrounds the second structure to the first structure in a plane orthogonal to the longitudinal axis and along at least a portion of a first portion of the longitudinal axis, such that the connection between the second and first structures is symmetrical about the longitudinal axis; and

[0254] An electrode arrangement is disposed on the surface of a second structure such that the electrode arrangement surrounds the longitudinal axis of the opening, and the surface of the second structure surrounds the electrode arrangement in a plane orthogonal to the longitudinal axis.

[0255] in:

[0256] The first surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a second portion of the longitudinal axis of the opening, the first surface surrounds the opening;

[0257] The second surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a third portion of the longitudinal axis, the second surface surrounds the opening;

[0258] The surface of the second structure is arranged along the longitudinal axis between the first surface and the second surface of the first structure;

[0259] The electrode arrangement and the first surface of the first structure are separated from each other in a direction parallel to the longitudinal axis, such that a first gap exists between the electrode arrangement and the first surface of the first structure; and

[0260] The electrode arrangement is separated from the second surface of the first structure in a direction parallel to the longitudinal axis, such that a second gap exists between the electrode arrangement and the second surface of the first structure.

[0261] Clause 2: The manipulator lens device according to Clause 1, wherein: the surface of the second structure completely surrounds the opening; the support completely surrounds the second structure; the first surface of the first structure completely surrounds the opening; the second surface of the first structure completely surrounds the opening; and / or the electrode arrangement completely surrounds the opening.

[0262] Clause 3: A manipulator lens device according to Clause 1 or 2, wherein the electrode arrangement is a single electrode.

[0263] Clause 4: A manipulator lens device according to any of the preceding clauses, wherein the opening is circular in a plane orthogonal to the longitudinal axis.

[0264] Clause 5: The manipulator lens device according to Clause 4, wherein in a plane orthogonal to the longitudinal axis, the radius of the opening at the first and second gaps is greater than the radius at the first and second portions of the longitudinal axis.

[0265] Clause 6: A manipulator lens device according to any of the preceding clauses, wherein the electrode arrangement is annular in a plane orthogonal to the longitudinal axis.

[0266] Clause 7: A manipulator lens device according to any of the preceding clauses, wherein the second structure is annular in a plane orthogonal to the longitudinal axis.

[0267] Clause 8: A manipulator lens device according to any of the preceding clauses, wherein the support is annular in a plane orthogonal to the longitudinal axis.

[0268] Clause 9: A manipulator lens device according to any of the preceding clauses, wherein the extent of the support along the longitudinal axis is smaller than the extent of the surface of the second structure.

[0269] Clause 10: A manipulator lens device according to any of the preceding clauses, wherein the longitudinal midpoint of the support member is in the same plane as the longitudinal midpoint of the surface of the second structure.

[0270] Clause 11: The manipulator lens assembly according to any of the preceding clauses further includes a feed line, wherein the feed line is electrically connected to the electrode arrangement.

[0271] Clause 12: The manipulator lens device according to Clause 11, wherein the feed line passes through the support and enters the second structure.

[0272] Clause 13: A manipulator lens device according to Clause 11 or 12, wherein the feed line is electrically connected to the electrode arrangement at the longitudinal midpoint of the electrode arrangement.

[0273] Clause 14: A manipulator lens device according to any one of Clauses 11 to 13, wherein the electrode arrangement is surrounded by feed lines in a plane orthogonal to the longitudinal axis.

[0274] Clause 15: A manipulator lens device according to any of the preceding clauses, wherein a first electrode is arranged in at least one plane orthogonal to the longitudinal axis and extends over at least one end of the second structure.

[0275] Clause 16: A manipulator lens assembly according to any of the preceding clauses, wherein the manipulator lens assembly is symmetrical about a longitudinal axis.

[0276] Clause 17: A manipulator lens device according to any of the preceding clauses, wherein the charged particle is an electron.

[0277] Clause 18: A manipulator lens device according to any of the preceding clauses, wherein: the manipulator lens device comprises a first part and a second part; and the first part of the manipulator lens device is incorporated into the second part of the manipulator lens device.

[0278] Clause 19: The manipulator lens device according to Clause 18, when Clause 18 is subordinate to any of Clauses 11 to 17, wherein a plane substantially at the longitudinal position of the feed and orthogonal to the longitudinal axis provides the boundary between the first part and the second part.

[0279] Clause 20: A manipulator lens assembly pursuant to Clause 19, wherein the second part of the manipulator lens assembly is a fundamental mirror image of the first part of the manipulator lens assembly.

[0280] Clause 21: A manipulator lens device according to any one of Clauses 18 to 20, wherein: a first portion of the manipulator lens device includes a first portion of a first structure; a second portion of the manipulator lens device includes a second portion of the first structure; the first portion of the first structure is a monolayer substrate; and the second portion of the first structure is a monolayer substrate.

[0281] Clause 22: A manipulator lens device according to any of the preceding clauses, wherein a first surface of a first structure and a second surface of a first structure are at the same potential; and optionally, the potential is a ground potential.

[0282] Clause 23: A manipulator lens device according to any of the preceding clauses, wherein the support is an electrical insulator, such as a dielectric.

[0283] Clause 24: A manipulator lens device pursuant to Clause 23, wherein the second structure is connected only to an electrical insulator.

[0284] Clause 25: The manipulator lens device according to Clause 24, wherein: the second structure includes a substrate; and the electrodes are arranged on the surface of the substrate.

[0285] Clause 26: A manipulator lens device pursuant to any of Clauses 23 to 25, wherein the second structure is configured such that: in use, the electrical insulator is shielded from the charged particle beam.

[0286] Clause 27: A manipulator lens device according to any one of Clauses 1 to 22, wherein: the support includes a substrate; the second structure includes a substrate; the second structure includes an electrically insulating layer, such as a dielectric, on the substrate; and an electrode arrangement is disposed on the electrically insulating layer.

[0287] Clause 28: A manipulator lens array comprising a plurality of manipulator lens devices according to any one of the preceding clauses; wherein the openings of all manipulator lens devices are formed by the same first structure.

[0288] Clause 29: A manipulator lens array pursuant to Clause 28, wherein the longitudinal axes of all openings of the manipulator lens assembly are substantially parallel to each other.

[0289] Clause 30: Manipulator lens array pursuant to Clause 28 or 29, wherein each manipulator device in the manipulator array is configured to focus different sub-beams in a plurality of beams.

[0290] Clause 31: A manipulator lens array according to any one of Clauses 28 to 30, wherein the opening of each manipulator lens device is completely surrounded by a portion of the first structure, such that each manipulator lens device is separated from all adjacent manipulator lens devices by the portion of the first structure in which the opening is formed.

[0291] Clause 32: A manipulator lens array according to any one of Clauses 28 to 30, wherein, for adjacent manipulator lens devices: a first gap in each manipulator lens device is formed by a first channel extending within a first structure between the manipulator lens devices; between each pair of adjacent manipulator lens devices, the first structure includes a first set of protrusions extending parallel to a longitudinal axis, such that a protrusion in the first set of protrusions blocks a linear path of the first channel between the first gaps of the adjacent manipulator lens devices; a second gap in each manipulator lens device is formed by a second channel extending within a substantially planar structure between the manipulator lens devices; and between each pair of adjacent manipulator lens devices, the first structure includes a second set of protrusions extending parallel to a longitudinal direction between the adjacent manipulator lens devices, such that a protrusion in the second set of protrusions blocks a linear path of the second channel between the second gaps of the adjacent manipulator lens devices.

[0292] Clause 33: Manipulator lens array pursuant to Clause 32, wherein at least some of the protrusions in the first group and / or the second group are grounded.

[0293] Clause 34: A method of manufacturing a manipulator lens device pursuant to Clause 18 or any of its dependent clauses, the method comprising: attaching a first portion of the manipulator lens device to a second portion of the manipulator lens device.

[0294] Clause 35: A single lens for focusing a charged particle beam, wherein the single lens comprises: a focusing electrode arrangement to which a voltage for focusing the charged particle beam is applied; a first electrode arrangement on a body of the single lens; and a second electrode arrangement on a body of the single lens, wherein the focusing electrode arrangement is arranged between a first and a second ground electrode arrangement along a longitudinal axis of the single lens, and the focusing electrode arrangement is electrically isolated from the first and second ground electrode arrangements; wherein the focusing electrode arrangement comprises: a structure having one or more electrodes formed thereon; and a support member that mechanically connects the structure to the body of the single lens in a plane orthogonal to the longitudinal axis by a connection symmetrical about the longitudinal axis.

[0295] Clause 36: The single lens according to Clause 35 also includes a feed line that enters the structure via a support in a plane orthogonal to the longitudinal axis and is electrically connected to one or more electrodes arranged in a focusing configuration.

[0296] Clause 37: A single lens according to Clause 35 or 36, wherein the first electrode arrangement and the second electrode arrangement are at the same potential; and optionally, the potential is ground potential.

[0297] Clause 38: A single lens configured to focus a beam of charged particles in a beam path during use, wherein the single lens includes: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be at a second potential; and a second electrode configured to be substantially at the first potential; the electrodes are arranged along the beam path such that the focusing electrode is between the first and second electrodes; wherein the focusing electrode is electrically isolated from the first and second electrodes, the focusing electrode including: an electrode surface; and a support member symmetrical about the beam path and configured to support and electrically connect the electrode surface in a plane orthogonal to the beam path.

[0298] Clause 39: A single lens according to Clause 38, wherein the support includes a feed line configured to pass through the support and be electrically connected to the electrode surface.

[0299] Clause 40: A single lens according to Clause 38, wherein the feed line passes through a support in a plane orthogonal to the longitudinal axis.

[0300] Clause 41: A single lens configured to focus a beam of charged particles in a beam path during use, wherein the single lens comprises: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be at a second potential, the focusing electrode extending along and symmetrically around the beam path; a second electrode configured to be substantially at the first potential; and a support configured to support the focusing electrode, wherein the focusing electrode is configured to be electrically isolated from the first and second electrodes, and the focusing electrode extends further along the beam path than the support, such that a dimensional difference along the beam path between the support and the focusing electrode provides a creep length parallel to the beam path.

[0301] Clause 42: A single lens configured to focus a beam of charged particles in a beam path during use, wherein the single lens comprises: a first electrode configured to be disposed at a first potential; a focusing electrode configured to be at a second potential, wherein the focusing electrode extends along and symmetrically around the beam path, and the focusing electrode includes an electrode surface on a structure; a second electrode configured to be substantially at the first potential; and a support configured to support the focusing electrode, the electrode being arranged along the beam path such that the focusing electrode is between the first and second electrodes, wherein the focusing electrode is configured to be electrically isolated from the first and second electrodes.

[0302] Clause 43: A single lens pursuant to Clause 42, wherein the support is an electrical insulator.

[0303] Clause 44: A single lens according to Clause 43, wherein the structure is connected only to the electrical insulator.

[0304] Clause 45: A single lens according to any one of Clauses 42 to 44, wherein: the structure includes a substrate; and one or more electrodes are on the surface of the substrate.

[0305] Clause 46: A single lens according to any one of Clauses 42 to 45, wherein the structure is configured such that: in use, the electrical insulator is shielded from the beam of charged particles focused by the single lens.

[0306] Clause 47: A single lens according to Clause 42, wherein: the support includes a substrate; the structure includes a substrate; the structure includes an electrically insulating layer on the substrate; and one or more electrodes are disposed on the electrically insulating layer.

[0307] Clause 48: A single lens according to any one of Clauses 42 to 47, wherein: the longitudinal extent of the structure along the longitudinal axis of the single lens is longer than the longitudinal extent of the support; and the structure and the support are arranged such that increasing the longitudinal extent of the structure relative to the longitudinal extent of the support increases the creep length of the focusing electrode arrangement.

[0308] Clause 49: A multi-array single lens configured to focus multiple charged particle sub-beams along a multi-beam path in use, wherein each single lens in the array includes: a focusing electrode located midway between an upstream electrode and a downstream electrode along the beam path and configured to be at a different potential from the upstream and downstream electrodes, wherein the focusing electrode is electrically isolated from the upstream and downstream electrodes; wherein the focusing electrode includes: an electrode surface; and a support; wherein the support is substantially symmetrical about the beam path; configured to support the electrode surface in a plane orthogonal to the beam path; and configured to be electrically connected to the electrode surface.

[0309] Clause 50: A multi-array single lens configured to focus multiple charged particle sub-beams along a multi-beam path in use, wherein each single lens in the array includes: a focusing electrode located between an upstream electrode and a downstream electrode and configured to be isolated from and at a different potential from the upstream and downstream electrodes, the focusing electrode extending along and substantially symmetrically around the beam path; and a support configured to support the focusing electrode; wherein the focusing electrode extends further along the beam path than the support, such that a dimensional difference between the support and the focusing electrode along the beam path provides a creep length parallel to the beam path.

[0310] Clause 51: A multi-array lens configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential from the inlet electrode during operation; and a support for supporting and electrically isolating the focusing electrode, wherein the focusing electrode is substantially rotationally symmetric about the sub-beam path.

[0311] Clause 52: A multi-array lens according to Clause 51, wherein each lens in the array further includes: an exit electrode; wherein a focusing electrode is upstream of the exit electrode along the sub-beam path and is configured to be at a different potential from the exit electrode during operation.

[0312] Clause 53: A multi-array lens (also referred to as a lens array) configured to focus multiple charged particle sub-beams along a multi-beam path in use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential from the inlet electrode, wherein the focusing electrode includes: an electrode surface; and a support; wherein the support is symmetrical about the sub-beam path; configured to support the electrode surface in a plane orthogonal to the beam path; configured to electrically isolate the focusing electrode from the inlet electrode; and configured to electrically connect the electrode surface.

[0313] Clause 54: Lens array according to Clause 53, wherein the polar surface further extends along the sub-bundle path of the support.

[0314] Clause 55: Lens array according to Clause 53 or 54, wherein the pole piece is configured to shield the sub-beam path from the support, preferably provided by the radial position of the focusing electrode relative to the support.

[0315] Clause 56: A lens array according to any one of Clauses 53 to 55, wherein the focusing electrode is electrically connected by a support; and preferably electrically isolated from the inlet electrode.

[0316] Clause 57: A lens array according to any one of Clauses 53 to 56, wherein each lens in the array further includes a feed line configured to electrically connect to a focusing electrode, the feed line preferably extending through a support in a direction orthogonal to the sub-beam path.

[0317] Clause 58: A lens array according to any one of Clauses 53 to 57, wherein the feed line is connected to the focusing electrode at the longitudinal midpoint of the focusing electrode.

[0318] Clause 59: A lens array as described in any of Clauses 53 to 58, wherein the support is cylindrical such that it has circular rotational symmetry with respect to the sub-beam path.

[0319] Clause 60: A lens array according to any one of Clauses 53 to 59, wherein the rotationally symmetric support is a plurality of longitudinal elements surrounding the periphery of the focusing electrode.

[0320] Clause 61: A lens array according to any one of Clauses 53 to 60, wherein a plurality of longitudinal elements are equidistantly spaced around the periphery of a focusing electrode.

[0321] Clause 62: A lens array according to any one of Clauses 53 to 61, wherein the support includes an insulator, preferably including a dielectric.

[0322] Clause 63: A lens array according to any one of Clauses 53 to 62, wherein each lens in the array further comprises: an exit electrode;

[0323] Clause 64: Lens array according to Clause 63, wherein the focusing electrode is upstream of the exit electrode along the sub-beam path and is configured to be at a different potential from the exit electrode during operation.

[0324] Clause 65: Lens array according to Clause 63 or 64, wherein the inlet and outlet electrodes are mirror symmetric relative to each other in a plane orthogonal to the sub-beam path.

[0325] Clause 66: A lens array according to any one of Clauses 53 to 65, wherein the lens array includes a substrate and preferably includes at least two adjacent substrates.

[0326] Clause 67: A lens array according to any one of Clauses 53 to 66, wherein the lens in the lens array is a single lens.

[0327] Clause 68: A multi-array single lens configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each single lens in the array includes: a focusing electrode located between upstream and downstream electrodes and configured to be isolated from and at a different potential from the upstream and downstream electrodes, wherein the focusing electrode extends along and substantially symmetrically around the beam path; and a support configured to support the focusing electrode; wherein the focusing electrode extends further along the sub-beam path than the support, such that the dimensional difference between the support and the focusing electrode along the beam path provides shielding of the beam path by the support.

[0328] Clause 69: A multi-array single lens according to Clause 68, wherein shielding is provided by the radial position of the focusing electrode relative to the support.

[0329] Clause 70: A multi-array lens configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each lens in the array includes: an inlet electrode; a focusing electrode downstream of the inlet electrode along the sub-beam path and configured to be at a different potential from the inlet electrode; and a support configured to support the focusing electrode relative to the inlet electrode, wherein the focusing electrode and the support are configured such that the lens generates a rotationally symmetric field about the sub-beam path in operation.

[0330] Clause 71: A multi-array lens array configured to focus multiple charged particle sub-beams along a multi-beam path in use, wherein each lens in the array comprises a manipulator lens device according to any one of Clauses 1 to 27, or a single lens according to Clauses 35 to 48.

[0331] Clause 72: An electro-optical system configured to project a plurality of charged particle sub-beams along a multi-beam path, wherein the projection optics system comprises a multi-array single lens according to any one of Clauses 49 to 50, 68 or 69, a manipulator lens array according to any one of Clauses 28 to 33, and / or a multi-array lens array according to any one of Clauses 51 to 67, 70 or 71.

[0332] Clause 73: A multi-beam inspection and / or measurement tool, including an electro-optical system according to Clause 72.

Claims

1. A manipulator lens device for focusing a beam of charged particles, wherein the manipulator lens device comprises: A first structure forms an opening through which the path of the charged particle beam through the manipulator lens device is substantially along the longitudinal axis of the opening; A second structure having a surface, wherein the surface surrounds the opening in a plane orthogonal to the longitudinal axis and along a first portion of the longitudinal axis; A support member, which connects the second structure to the first structure and surrounds the second structure in a plane orthogonal to the longitudinal axis and along at least a portion of the first portion of the longitudinal axis, such that the connection between the second structure and the first structure is symmetrical about the longitudinal axis. as well as An electrode arrangement is disposed on the surface of the second structure such that the electrode arrangement surrounds the longitudinal axis of the opening, and the surface of the second structure surrounds the electrode arrangement in a plane orthogonal to the longitudinal axis; a first surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a second portion of the longitudinal axis of the opening, the first surface surrounds the opening; The second surface of the first structure is arranged such that: in a plane orthogonal to the longitudinal axis and along at least a third portion of the longitudinal axis, the second surface surrounds the opening; The surface of the second structure is arranged along the longitudinal axis between the first surface and the second surface of the first structure; The electrode arrangement is separated from the first surface of the first structure in a direction parallel to the longitudinal axis, such that a first gap exists between the electrode arrangement and the first surface of the first structure. as well as The electrode arrangement is separated from the second surface of the first structure in a direction parallel to the longitudinal axis, such that a second gap exists between the electrode arrangement and the second surface of the first structure. Along the longitudinal axis, the range of the support member is smaller than the range of the surface and / or the range of the electrode arrangement of the second structure.

2. The manipulator lens device according to claim 1, wherein: The surface of the second structure completely surrounds the opening; The support completely surrounds the second structure; The first surface of the first structure completely surrounds the opening; The second surface of the first structure completely surrounds the opening; and / or The electrode arrangement completely surrounds the opening.

3. The manipulator lens device according to claim 1 or 2, wherein the electrode arrangement is a single electrode.

4. The manipulator lens device according to claim 1 or 2, wherein the opening is circular in a plane orthogonal to the longitudinal axis.

5. The manipulator lens device according to claim 1 or 2, wherein, In a plane orthogonal to the longitudinal axis, at least one of the electrode arrangement, the second structure, and the support is annular.

6. The manipulator lens device according to claim 1 or 2, wherein the second structure is annular in a plane orthogonal to the longitudinal axis.

7. The manipulator lens device according to claim 1 or 2, wherein the longitudinal midpoint of the support member is in the same plane as the longitudinal midpoint of the surface of the second structure.

8. The manipulator lens device according to claim 1 or 2, the manipulator lens device further comprising a feed line, wherein the feed line is electrically connected to the electrode arrangement.

9. The manipulator lens device according to claim 8, wherein, a. The feed line passes through the support member and enters the second structure; b. The feeder is electrically connected to the electrode arrangement at the longitudinal midpoint of the electrode arrangement; and / or c. In a plane orthogonal to the longitudinal axis, the electrode arrangement is surrounded by the feed line.

10. The manipulator lens device according to claim 1 or 2, wherein the first electrode in the electrode arrangement extends at least one end of the second structure in at least one plane orthogonal to the longitudinal axis.

11. The manipulator lens device according to claim 1 or 2, wherein the manipulator lens device is symmetrical about the longitudinal axis.

12. The manipulator lens device according to claim 1 or 2, wherein: The manipulator lens device includes a first part and a second part; and the first part of the manipulator lens device is coupled to the second part of the manipulator lens device.

13. The manipulator lens device according to claim 12, wherein: The first part of the manipulator lens device includes a first part of the first structure; the second part of the manipulator lens device includes a second part of the first structure; the first part of the first structure is a single-layer substrate; and the second part of the first structure is a single-layer substrate.

14. The manipulator lens device according to claim 1 or 2, wherein the first surface of the first structure and the second surface of the first structure are at the same potential.

15. The manipulator lens device according to claim 14, wherein the potential is a ground potential.

16. The manipulator lens device according to claim 1 or 2, wherein the support is an electrical insulator.

17. The manipulator lens device of claim 16, wherein the second structure is connected only to the electrical insulator.

18. The manipulator lens device according to claim 16, wherein: The second structure includes a substrate; and the electrodes are arranged on the surface of the substrate.

19. The manipulator lens device of claim 16, wherein the second structure is configured such that, in use, the electrical insulator is shielded from the charged particle beam.

20. The manipulator lens device of claim 18, wherein the second structure is configured such that, in use, the electrical insulator is shielded from the charged particle beam.

21. The manipulator lens device according to claim 12, wherein: The support includes a substrate; The second structure includes a substrate; The second structure includes an electrically insulating layer on the substrate; and The electrode arrangement is disposed on the electrical insulating layer.

22. A method of manufacturing a manipulator lens device according to claim 21, the method comprising: The first part of the manipulator lens assembly is joined to the second part of the manipulator lens assembly.

23. A lens array configured to focus a plurality of charged particle sub-beams along a multi-beam path in use, wherein each lens in the array comprises a manipulator lens device according to any one of claims 1 to 21.

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