Charged particle manipulation device

Abstract

To provide a multi-beam manipulator device that acts on sub-beams of a multi-beam to deflect sub-beam paths.SOLUTION: The device includes: an electrode as pairs of parallel surfaces. Each pair of parallel surfaces includes a first surface that is arranged along a side of a corresponding line of sub-beams, and a second surface that is arranged parallel to the first surface and along an opposite side of the corresponding line of sub-beam paths. A first pair of parallel surfaces is configured to electrostatically interact with an entire line of sub-beams in the multi-beam so as to be capable of applying a deflection amount to the paths of sub-beams in a first direction. A second pair of parallel surfaces is configured to electrostatically interact with an entire line of sub-beams in the multi-beam so as to be capable of applying another deflection amount to the paths of sub-beams in a second direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to European Patent Application No. 20156253.5, filed February 7, 2020, which is incorporated herein by reference in its entirety.

[0002] Field

[0002] The embodiments provided herein relate generally to the manipulation of charged particles in a multi-beam charged particle device. The embodiments provide a plurality of electrode pairs, each electrode pair arranged to simultaneously manipulate a plurality of charged particle sub-beams. [Background technology]

[0003]

[0003] In manufacturing semiconductor integrated circuit (IC) chips, for example as a result of optical effects and accidental particles, undesired pattern defects inevitably occur on the substrate (i.e., wafer) or mask during the fabrication process, thereby reducing the yield. Therefore, monitoring the extent of undesired pattern defects is an important process in the manufacture of IC chips. More generally, inspection and / or measurement of the surface of a substrate or other object / material is an important process during and / or after its manufacture.

[0004]

[0004] Pattern inspection tools using charged particle beams have been used to inspect objects, for example to detect pattern defects. These tools typically use electron microscopy techniques, such as scanning electron microscopes (SEMs). In an SEM, a primary electron beam of relatively high energy electrons is targeted with a final deceleration step to land on a sample with a relatively low landing energy. The electron beam is focused as a probing spot on the sample. Interaction of the landing electrons from the electron beam with material structures at the probing spot 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 structures of the sample. By scanning the primary electron beam as a probing spot across the sample surface, secondary electrons can be emitted across the surface of the sample. By collecting these emitted secondary electrons from the sample surface, the pattern inspection tool can obtain an image that represents the characteristics of the material structure of the surface of the sample.

[0005]

[0005] Another application of charged particle beams is lithography. The charged particle beam reacts with a resist layer on the surface of a substrate. A desired pattern in the resist can be created by controlling the location on the resist layer where the charged particle beam is directed.

[0006]

[0006] A charged particle device may be a device that generates, illuminates, projects, and / or detects one or more charged particle beams. There is a general need for improving known techniques for manipulating one or more charged particle beams. Summary of the Invention

[0007] overview

[0007] The embodiments provided herein disclose a manipulator device for manipulating one or more charged particle beams. The manipulator device may be a deflector for simultaneously deflecting multiple sub-beams of a multi-beam. The manipulator device may be included by a charged particle device. The charged particle device may be a device for generating, illuminating, projecting, and / or detecting one or more charged particle beams.

[0008]

[0008] According to a first aspect of the present invention, there is provided a multi-beam manipulator device configured to deflect a plurality of sub-beam paths by acting on the paths of a plurality of sub-beams of a charged particle multi-beam, wherein the sub-beams are arranged in an array in which the sub-beams are arranged in a plurality of lines, the multi-beam manipulator device comprising a set of electrodes comprising a plurality of parallel planar electrode surface pairs, a first parallel planar electrode surface pair in the set comprising a first planar electrode surface arranged along one side of one of the lines of sub-beams and a second planar electrode surface parallel to the first planar electrode surface and arranged along an opposite side of said one of the lines of sub-beam paths, the second parallel planar electrode surface pair in the set comprising a first planar electrode surface arranged along one side of said one of the lines of sub-beam paths, a first planar electrode surface arranged along one side of another of the lines of sub-beam paths and a second planar electrode surface parallel to the first planar electrode surface and arranged along an opposite side of the other of the lines of sub-beam paths, the first pair of parallel planar electrode surfaces configured to electrostatically interact with the entire line of sub-beams of the multi-beam to apply a first deflection amount to the paths of the sub-beams in a first direction and the second pair of parallel planar electrode surfaces configured to electrostatically interact with the entire line of sub-beams of the multi-beam to apply a second deflection amount to the paths of the sub-beams in a second direction, the first direction being opposite to the second direction.

[0009]

[0009] According to a second aspect of the present invention, there is provided a multi-beam manipulator arrangement comprising a first multi-beam manipulator device according to the first aspect and one or more further multi-beam manipulator devices, each of the one or more further multi-beam manipulator devices being a multi-beam manipulator device according to the first aspect, wherein each multi-beam manipulator device is positioned at a different position along a charged particle optical axis of the multi-beam manipulator arrangement.

[0010]

[0010] According to a third aspect of the present invention, there is provided a charged particle system comprising a charged particle source arranged to emit a beam, a multi-beam generator arranged to generate a multi-beam based on the beam, the multi-beam comprising a plurality of sub-beams, and either a multi-beam manipulator device according to the first aspect or a multi-beam manipulator arrangement according to the second aspect configured to manipulate paths of sub-beams of the multi-beam generated by the multi-beam generator.

[0011] According to a fourth aspect of the present invention there is provided an electron beam inspection tool including a charged particle system according to the third aspect.

[0012] According to a fifth aspect of the present invention there is provided an electron beam lithography tool including a charged particle system according to the third aspect.

[0013]

[0013] According to a sixth aspect of the present invention, there is provided a multi-beam manipulator device configured to act on a plurality of sub-beam paths of a charged particle multi-beam to deflect the plurality of sub-beam paths, the sub-beams being arranged in an array in which the sub-beams are arranged in a series of lines, the multi-beam manipulator device comprising a plurality of parallel planar electrode surface pairs, a first parallel planar electrode surface pair comprising two opposing planar parallel electrode surfaces arranged on either side along at least one of the lines of the sub-beams and a second parallel planar electrode surface pair comprising two opposing planar parallel electrode surfaces arranged on either side along at least another one of the lines of the sub-beams, the first parallel planar electrode surface pair and the second parallel planar electrode surface pair extending across the multi-beam to intersect the array and configured, in operation, to electrostatically interact with each sub-beam path in the line between the surface pairs.

[0014]

[0014] According to a seventh aspect of the present invention, there is provided a multibeam manipulator configured to manipulate an array of sub-beam paths of a charged particle multi-beam, the sub-beams being arranged in lines in the array, the lines being in at least two different line directions, the multibeam manipulator device comprising a number of deflector devices corresponding to a number of line directions in the array and arranged at different positions on the path of the multi-beam, each deflector device comprising a plurality of parallel planar electrode surface pairs, the parallel planar electrode surfaces of each deflector device being aligned in different line directions, the plurality of parallel planar electrode surface pairs being arranged on either side along at least one of the lines of the sub-beams .... A multi-beam manipulator is provided comprising: a first parallel planar electrode surface pair including two opposing planar-parallel electrode surfaces; and a second parallel planar electrode surface pair including two opposing planar-parallel electrode surfaces arranged on either side along at least another one of the lines of sub-beams, where the at least another one of the lines of sub-beams is parallel to at least one of the lines of sub-beams, the first parallel planar electrode surface pair and the second parallel planar electrode surface pair extending across the multi-beam to intersect the array and configured, in operation, to electrostatically interact with each sub-beam path in the line between the surface pairs.

[0015]

[0015] According to an eighth aspect of the present invention, there is provided a multi-beam manipulator configured to manipulate an array of sub-beam paths of a charged particle multi-beam, wherein the sub-beams are arranged in lines in the array, the lines being in at least two different line directions, the multi-beam manipulator device includes a number of deflector devices corresponding to the number of line directions in the array and positioned along the multi-beam paths, each deflector device includes a plurality of planar-parallel opposing electrode surfaces, the planar-parallel electrode surfaces of each deflector device being aligned in different line directions, the plurality of parallel planar electrode surface pairs including at least two opposing parallel planar electrode surface pairs, wherein each opposing planar-parallel surface pair is configured to cross across the multi-beam array on either side of another at least one line of the sub-beam paths such that, in operation, each opposing parallel planar electrode surface pair electrostatically interacts with all of the sub-beam paths in a respective at least one line between said surfaces.

[0016]

[0016] According to a ninth aspect of the present invention, there is provided a method for deflecting paths of a plurality of sub-beams of a charged particle multi-beam, wherein the sub-beams are arranged in an array in which the sub-beams are arranged in a plurality of lines, the method comprising electrostatically interacting with an entire first line of sub-beams of the multi-beam such that a first deflection amount is applied to the path of the sub-beam in a first direction, and electrostatically interacting with an entire second line of sub-beams of the multi-beam such that a second deflection amount is applied to the path of the sub-beam in a second direction, the first direction being opposite to the second direction.

[0017]

[0017] Other advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, in which are set forth, by way of illustration and example, certain embodiments of the invention.

[0018]

[0018] The above and other aspects of the present disclosure will become more apparent from the following description of exemplary embodiments taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram illustrating an exemplary charged particle beam inspection apparatus. [Diagram 2]

[0020] 2 is a schematic diagram illustrating an example multi-beam device that is part of the example charged particle beam inspection apparatus of FIG. 1. [Diagram 3]

[0021] 2 is a schematic diagram of an exemplary multi-beam device illustrating an exemplary configuration of a source conversion unit of the exemplary charged particle beam inspection apparatus of FIG. 1. [Figure 4]

[0022] 1 is a schematic diagram of a manipulator device according to an embodiment. [Diagram 5]

[0023] 1 is a schematic diagram of a manipulator device according to an embodiment. [Figure 6]

[0024] 1 illustrates an arrangement of two manipulator devices according to an embodiment. [Figure 7A]

[0025] FIG. 2 is a schematic diagram of sub-beams in an arrangement of a line of sub-beams. [Figure 7B]

[0026] 13 illustrates how multiple manipulator devices can be aligned, according to one embodiment. [Figure 8]

[0027] 1 shows a manipulator array including multiple manipulators for manipulating the sub-beams. [Figure 9]

[0028] 1 is a schematic diagram showing a cross section through a portion of a charged particle device; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020]

[0029] Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, in which the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the present invention. Instead, the implementations are merely examples of apparatus and methods consistent with related aspects of the present invention, as described in the appended claims.

[0021]

[0030] Increases in the computational power of electronic devices, which reduces the physical size of the device, can be achieved by greatly increasing the packing density of circuit components such as transistors, capacitors, and diodes on an IC chip. This has been made possible by improvements in resolution that allow the creation of even smaller structures. For example, an IC chip in a smartphone the size of a thumbnail and available before 2019 can contain over 2 billion transistors, each less than 1 / 1000 the size of a human hair. It is therefore not surprising that semiconductor IC manufacturing is a complex and time-consuming process with hundreds of individual steps. An error in even one step can dramatically affect the functionality of the final product. Just one "killer defect" can result in the failure of the device. The goal of a manufacturing process is to improve the overall yield of the process. For example, to obtain a 75% yield for a process with 50 steps (where steps can refer to the number of layers formed on a wafer), the individual steps must have a yield of greater than 99.4%. If each individual step has a yield of 95%, the overall process yield is as low as 7%.

[0022]

[0031] In IC chip manufacturing facilities, while high process yields are desirable, it is also essential to maintain high substrate (i.e., wafer) throughput, defined as the number of substrates processed per hour. High process yields and high substrate throughput can be affected by the presence of defects. This is especially true when operator intervention is required to investigate the defects. Thus, high throughput detection and identification of micro- and nano-scale defects by inspection tools, such as scanning electron microscopes ("SEMs"), is essential to maintain high yields and low costs.

[0023]

[0032] The SEM includes a scanning device and a detector device. The scanning device includes an illumination device, which includes an electron source for generating primary electrons, and a projection device for scanning a sample, such as a substrate, with one or more focused beams of primary electrons. The primary electrons interact with the sample and generate secondary electrons. The detector device captures the secondary electrons from the sample as it is scanned so that the SEM can generate an image of the scanned area of ​​the sample. For high-throughput inspection, some inspection devices use multiple focused beams of primary electrons, i.e., multibeams. The component beams of a multibeam are sometimes called subbeams or beamlets. The multibeams can scan different parts of the sample simultaneously. Thus, multibeam inspection devices can inspect samples much faster than single-beam inspection devices.

[0024]

[0033] In a multi-beam inspection apparatus, some paths of the primary electron beam 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 angle of incidence and / or at the desired pitch and / or at the desired location of the sample surface, sub-beam paths with a larger radial distance from the central axis need to be manipulated to move a larger angle than sub-beam paths with paths closer to the central axis. This stronger manipulation can cause aberrations, which result in blurred out-of-focus images of the sample substrate. In particular, for sub-beam paths that are not on the central axis, the aberrations of the sub-beams can increase with radial displacement from the central axis, since the manipulators of these sub-beam paths are required to operate with a larger voltage. Such aberrations can remain associated with secondary electrons upon detection of the secondary electrons. Thus, such aberrations reduce the quality of the images produced during the inspection.

[0025]

[0034] Known implementations of multi-beam inspection devices are described below.

[0026]

[0035] The figures are schematic. Thus, in the drawings, the relative dimensions of the components are exaggerated for clarity. In the following description of the drawings, the same or similar reference numbers refer to the same or similar components or entities, and only differences relative to the individual embodiments are described. Although the description and drawings are directed to an electro-optical device, it is understood that the embodiments are not used to limit the present disclosure to a particular charged particle. Thus, throughout this document, references to electrons can be considered to be references to charged particles more generally, and charged particles are not necessarily electrons.

[0027]

[0036] Reference is now made to Figure 1, which is a schematic diagram illustrating an exemplary charged particle beam inspection apparatus 100. The charged particle beam inspection apparatus 100 of Figure 1 includes a main chamber 10, a load lock chamber 20, an electron beam tool 40, a front end equipment module (EFEM) 30, and a controller 50. The electron beam tool 40 is located within the main chamber 10.

[0028]

[0037] The EFEM 30 includes a first load port 30a and a second load port 30b. The EFEM 30 may include one or more additional load ports. The first load port 30a and the second load port 30b can receive, for example, a substrate front opening unified pod (FOUP) containing a substrate to be inspected (e.g., a semiconductor substrate or a substrate made of other materials) or a sample (hereinafter, substrates, wafers, and samples are collectively referred to as "samples"). One or more robotic arms (not shown) of the EFEM 30 transport the sample to the load lock chamber 20.

[0029]

[0038] The load lock chamber 20 is used to remove gas from around the sample. This creates a vacuum, which is a local gas pressure lower than the pressure of the surrounding environment. The load lock chamber 20 may be connected to a load lock vacuum pumping system (not shown), which removes gas particles in the load lock chamber 20. Operation of the load lock vacuum pumping system allows the load lock chamber to reach a first pressure below atmospheric pressure. After the first pressure is reached, one or more robotic arms (not shown) transport the sample from the load lock chamber 20 to the main chamber 10. The main chamber 10 is connected to a main chamber vacuum pumping system (not shown). The main chamber vacuum pumping system removes gas particles in the main chamber 10 such that the pressure around the sample reaches a second pressure below the first pressure. After the second pressure is reached, the sample is transported to an electron beam tool, where the sample can be inspected by the electron beam tool. The electron beam tool 40 may include either a single beam or a multi-beam electron optical device.

[0030]

[0039] The controller 50 is electronically 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 apparatus 100. The controller 50 may also include processing circuitry configured to perform various signal and image processing functions. In FIG. 1, the controller 50 is shown as being external to the structure including the main chamber 10, the load lock chamber 20, and the EFEM 30, but it is understood that the controller 50 may be part of the structure. The controller 50 may be located within one of the component elements of the charged particle beam inspection apparatus, or the controller 50 may be distributed among at least two of the component elements. While the present disclosure provides an example of a main chamber 10 housing an electron beam inspection tool, it should be noted that aspects of the present disclosure are not limited in a broad sense to a chamber housing an electron beam inspection tool. Rather, it is understood that the principles described above may be applied to other tools and other arrangements of the apparatus operating under a second pressure.

[0031]

[0040] Referring now to FIG. 2, FIG. 2 is a schematic diagram illustrating an exemplary electron beam tool 40 including a multi-beam inspection tool that is part of the exemplary charged particle beam inspection apparatus 100 of FIG. 1. The multi-beam electron beam tool 40 (also referred to herein as apparatus 40) includes an electron source 201, a gun aperture plate 271, a condenser lens 210, a source conversion unit 220, a primary projection apparatus 230, a motorized stage 209, and a sample holder 207. The electron source 201, the gun aperture plate 271, the condenser lens 210, and the source conversion unit 220 are components of an illumination apparatus encompassed by 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 further include a secondary projection apparatus 250 and an associated electron detection device 240. The primary projection apparatus 230 may include an objective lens 231. The electronic detection device 240 may include a number of detection elements 241, 242, and 243. The beam separator 233 and the deflection scanning unit 232 may be located within the primary projection arrangement 230.

[0032]

[0041] The components used to generate the primary beam may be aligned with a primary electron optical axis of the apparatus 40. These components may include the electron source 201, the gun aperture plate 271, the condenser lens 210, the source conversion unit 220, the beam separator 233, the deflection scanning unit 232, and the primary projection arrangement 230. The secondary projection arrangement 250 and its associated electron detection device 240 may be aligned with a secondary electron optical axis 251 of the apparatus 40.

[0033]

[0042] The primary electron optical axis 204 is constituted by the electron optical axis of the portion of the electron beam tool 40 that is an illumination device. The secondary electron optical axis 251 is the electron optical axis of the portion of the electron beam tool 40 that is a detection device. The primary electron optical axis 204 is sometimes referred to herein as the main optical axis (for ease of reference), or the primary charged particle optical axis. The secondary electron optical axis 251 is sometimes referred to herein as the secondary optical axis, or the secondary charged particle optical axis.

[0034]

[0043] The electron source 201 may include a cathode (not shown) and an extractor or anode (not shown). During operation, the electron source 201 is configured to emit electrons from the cathode as primary electrons. The primary electrons are extracted or accelerated by the extractor and / or anode to form a primary electron beam 202 that forms a primary beam crossover (virtual or real image) 203. The primary electron beam 202 can be visualized as emitting from the primary beam crossover 203.

[0035]

[0044] In this arrangement, the primary electron beam is multi-beam by the time it reaches the sample, preferably before it reaches the projection device. Such multi-beams can be generated from the primary electron beam in many different ways. For example, the multi-beams can be generated by a multi-beam array located before the crossover, a multi-beam array located at 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 steering elements arranged in an array across the beam path. Each steering element can affect the primary electron beam to generate a sub-beam. Thus, the multi-beam array generates a multi-beam path at the down beam of the multi-beam array by interacting with the incoming primary beam path.

[0036]

[0045] The gun aperture plate 271 is configured, in operation, to block peripheral electrons of the primary electron beam 202 to reduce the Coulomb effect, which can enlarge the size of the probe spots 221, 222, and 223 of the primary sub-beams 211, 212, 213, respectively, and thus reduce the inspection resolution. The gun aperture plate 271 is sometimes also referred to as a Coulomb aperture array.

[0037]

[0046] The condenser lens 210 is configured to focus the primary electron beam 202. The condenser lens 210 may be designed to focus the primary electron beam 202 into a parallel beam and perpendicularly incident on the source conversion unit 220. The condenser lens 210 may be a movable condenser lens that may be configured such that the position of the first principal plane is movable. The movable condenser lens may be configured to be magnetic. The condenser lens 210 may be an anti-rotation condenser lens and / or it may be movable.

[0038]

[0047] The source conversion unit 220 may include an image forming element array, an aberration compensator array, a beam limiting aperture array, and a pre-bending micro-deflector array. The pre-bending micro-deflector array may deflect the multiple primary sub-beams 211, 212, 213 of the primary electron beam 202 so that they perpendicularly enter the beam limiting aperture array, the image forming element array, and the aberration compensator array. In this arrangement, the image forming element array may function as a multi-beam array for generating 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, micro-lenses (or a combination of both), one for each of the primary sub-beams 211, 212, 213, to influence the multiple primary sub-beams 211, 212, 213 of the primary electron beam 202 and to form multiple parallel images (virtual or real) of the primary beam crossover 203. 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 a plurality of microlenses for compensating for the field curvature aberration of the primary sub-beams 211, 212, and 213. The astigmatism compensator array may include a plurality of micro-astigmatizers for compensating for the astigmatism of the primary sub-beams 211, 212, and 213. The beam-limiting aperture array may be configured to limit the diameter of the individual primary sub-beams 211, 212, and 213. Although FIG. 2 shows three primary sub-beams 211, 212, and 213 as an example, it is to be understood that the source conversion unit 220 may be configured to form any number of primary sub-beams. 1, such as the source conversion unit 220, the electron detection device 240, the primary projection device 230, or the motorized stage 209. As described in more detail below, the controller 50 may perform various image and signal processing functions. The controller 50 may also generate various control signals for controlling the operation of the charged particle beam inspection apparatus, including the charged particle multi-beam device.

[0039]

[0048] The condenser lens 210 may further be configured to adjust the current of the primary sub-beams 211, 212, 213 at the down beam of the source conversion unit 220 by varying the focusing power of the condenser lens 210. Alternatively or additionally, the current of the primary sub-beams 211, 212, 213 may be changed by changing the radial size of the beam-limiting aperture in the beam-limiting aperture array corresponding to the individual primary sub-beams. The current may be changed by changing both the radial size of the beam-limiting aperture and the focusing power of the condenser lens 210. If the condenser lens is movable and magnetic, off-axis sub-beams 212 and 213 illuminating the source conversion unit 220 with a rotation angle may result. The rotation angle changes with the focusing power or the position of the first principal plane of the movable condenser lens. The condenser lens 210, which is an anti-rotation condenser lens, may be configured such that the rotation angle remains unchanged while the focusing power of the condenser lens 210 is changed. Such a focusing lens 210, which is also movable, may not change its rotation angle when the focusing power of the focusing lens 210 and the position of its first principal plane change.

[0040]

[0049] The objective lens 231 may be configured to focus the sub-beams 211 , 212 , and 213 onto the sample 208 for inspection, forming three probe spots 221 , 222 , and 223 on the surface of the sample 208 .

[0041]

[0050] The beam separator 233 may be, for example, a Wien filter including electrostatic deflectors generating electrostatic and magnetic dipole fields (not shown in FIG. 2). In operation, the beam separator 233 may be configured to exert an electrostatic force on individual electrons of the primary sub-beams 211, 212, and 213 by the electrostatic dipole field. This electrostatic force is equal in magnitude but opposite in direction to the magnetic force exerted on the individual electrons by the magnetic dipole field of the beam separator 233. Thus, the primary sub-beams 211, 212, and 213 may pass at least substantially straight through the beam separator 233 with at least substantially zero deflection angle.

[0042]

[0051] The deflection scanning unit 232 is configured to deflect the primary sub-beams 211, 212, and 213 in operation to scan the probe spots 221, 222, and 223 over respective scanning areas of a section of the surface of the sample 208. In response to the incidence of the primary sub-beams 211, 212, and 213 or the probe spots 221, 222, and 223 on the sample 208, electrons including secondary electrons and backscattered electrons are generated from the sample 208. The secondary electrons propagate in three secondary electron beams 261, 262, and 263. The secondary electron beams 261, 262, and 263 typically comprise secondary electrons (having an electron energy of 50 eV or less) and may also comprise at least a portion of backscattered electrons (having an electron energy between 50 eV and the landing energy of the primary sub-beams 211, 212, and 213). The beam separator 233 is arranged to deflect the paths of the secondary electron beams 261, 262, and 263 towards the secondary projection arrangement 250. The secondary projection arrangement 250 then focuses the paths of the secondary electron beams 261, 262, and 263 onto a number of detection areas 241, 242, and 243 of the electron detection device 240. The detection areas may be separate detection elements 241, 242, and 243 arranged to detect corresponding secondary electron beams 261, 262, and 263. The detection areas generate corresponding signals which are sent to the controller 50 or a signal processing system (not shown), for example, to construct an image of a corresponding scanned area of ​​the sample 208.

[0043]

[0052] The detector elements 241, 242, and 243 can detect corresponding secondary electron beams 261, 262, and 263. Upon incidence of the secondary electron beams on the detector elements 241, 242, and 243, the elements can generate corresponding intensity signal outputs (not shown). The outputs can be directed to an image processing system (e.g., controller 50). Each detector element 241, 242, and 243 can include one or more pixels. The intensity signal output of a detector element can be the sum of signals generated by all pixels within the detector element.

[0044]

[0053] The controller 50 may include an image processing system including an image acquirer (not shown) and a storage device (not shown). For example, the controller may include a processor, a computer, a server, a mainframe host, a terminal, a personal computer, any type of mobile computing device, etc., or a combination thereof. The image acquirer may include at least a portion of the processing functions of the controller. Thus, 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 the apparatus 40 that allows for signal communication, such as electrical conductors, fiber optic cables, portable storage media, IR, Bluetooth, Internet, wireless networks, wireless radios, or combinations thereof, among others. The image acquirer may receive signals from the electronic detection device 240, process data contained in the signals, and construct an image therefrom. Thus, the image acquirer may acquire an image of the sample 208. The image acquirer may also perform various post-processing functions, such as generating contours and superimposing indicators on the acquired image. The image acquirer may be configured to make adjustments, such as brightness and contrast, of the acquired image. The storage may be a storage medium such as a hard disk, a flash drive, cloud storage, random access memory (RAM), other types of computer readable memory, etc. The storage may be coupled to the image acquirer and may be used to store raw scanned image data as original images or to store post-processed images.

[0045]

[0054] The image acquirer may acquire one or more images of the sample based on the imaging signal received from the electronic detection device 240. The imaging signal may correspond to a scanning operation to perform charged particle imaging. The acquired image may be a single image including multiple imaging areas. The single image may be saved to the storage. The single image may be an original image that may be divided into multiple regions. Each region may include one imaging area that includes a feature of the sample 208. The acquired image may include multiple images of a single imaging area of ​​the sample 208 sampled multiple times over a period of time. The multiple images may be saved to the storage. The controller 50 may be configured to perform an image processing step using multiple images of the same location of the sample 208.

[0046]

[0055] The controller 50 may include measurement circuitry (e.g., an analog-to-digital converter) to obtain a distribution of detected secondary electrons. The electron distribution data collected during the detection time window, in combination with the corresponding scan path data of each of the primary sub-beams 211, 212, and 213 incident on the sample surface, can be used 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.

[0047]

[0056] The controller 50 may control the motorized stage 209 to move the sample 208 during inspection of the sample 208. The controller 50 may enable the motorized stage 209 to move the sample 208 in a direction, e.g., at a constant speed, preferably continuously, at least during inspection of the sample. The controller 50 may control the movement of the motorized stage 209 such that the motorized stage 209 varies the speed of movement of the sample 208 depending on various parameters. For example, the controller may control the stage speed (including its direction) depending on the characteristics of the inspection step of the scanning process.

[0048]

[0057] 2 shows that apparatus 40 uses three primary electron sub-beams, it is understood that apparatus 40 may use two or more primary electron sub-beams, and the present disclosure does not limit the number of primary electron beams used in apparatus 40.

[0049]

[0058] Referring now to Figure 3, Figure 3 is a schematic diagram of an exemplary multi-beam apparatus illustrating an exemplary configuration of a source conversion unit of the exemplary charged particle beam inspection apparatus of Figure 1. The apparatus 300 may include an electron source 301, a pre-sub-beam forming aperture array 372, a condenser lens 310 (similar to the condenser lens 210 of Figure 2), a source conversion unit 320, an objective lens 331 (similar to the objective lens 231 of Figure 2), and a sample 308 (similar to the sample 208 of Figure 2). The electron source 301, the pre-sub-beam forming aperture array 372, and the condenser lens 310 may be components of an illumination apparatus contained by the apparatus 300. The source conversion unit 320 and the objective lens 331 may be components of a projection apparatus contained by the apparatus 300. The source conversion unit 320 may be similar to the source conversion unit 220 of Fig. 2, where the image forming element array of Fig. 2 is the image forming element array 322, the aberration compensator array of Fig. 2 is the aberration compensator array 324, the beam limiting aperture array of Fig. 2 is the beam limiting aperture array 321, and the pre-bent micro deflector array of Fig. 2 is the pre-bent micro deflector array 323. The electron source 301, the pre-sub-beam forming aperture array 372, the condenser lens 310, the source conversion unit 320, and the objective lens 331 are aligned with the primary electron optical axis 304 of the apparatus. The electron source 301 generates a primary electron beam 302 generally along the primary electron optical axis 304 and with a source crossover (virtual or real image) 301S. The pre-sub-beam forming aperture array 372 cuts off peripheral electrons of the primary electron beam 302 to reduce the resulting Coulomb effect. The Coulomb effect is a cause of aberrations to the sub-beams due to interactions between electrons in different sub-beam paths. The primary electron beam 302 can be reduced to a specified number of sub-beams (such as three sub-beams 311, 312, and 313) by the pre-sub-beam forming aperture array 372 of the pre-sub-beam forming mechanism. Although three sub-beams and their paths are referenced above and in the following description, it is understood that the description is intended to apply to an apparatus, tool, or system using any number of sub-beams.

[0050]

[0059] The source conversion unit 320 may include a beamlet limiting aperture array 321 with beam limiting apertures configured to limit the sub-beams 311, 312, and 313 of the primary electron beam 302. The source conversion unit 320 may also include an image forming element array 322 with image forming micro-deflectors 322_1, 322_2, and 322_3. There is a respective micro-deflector associated with the path of each sub-beam. The micro-deflectors 322_1, 322_2, and 322_3 are configured to deflect the paths of the sub-beams 311, 312, and 313 towards the electron optical axis 304. The deflected sub-beams 311, 312, and 313 form a virtual image of the source crossover 301S. The virtual image is projected by the objective lens 331 onto the sample 308 and forms probe spots on the sample, which are the three probe spots 391, 392, and 393. Each probe spot corresponds to an incidence location of a sub-beam path on the sample surface. The source transformation unit 320 may further include an aberration compensator array 324 configured to compensate for the aberration of each sub-beam. The aberration of each sub-beam is generally present on the probe spots 391, 392, and 393 formed on the sample surface. The aberration compensator array 324 may include a field curvature compensator array (not shown) with microlenses. The field curvature compensators and microlenses are configured to compensate the sub-beams for field curvature aberrations prominent at the probe spots 391, 392, and 393. The aberration compensator array 324 may include an astigmatism compensator array (not shown) with micro-astigmatism correctors. The micro-astigmatism correctors are controlled to act on the sub-beams to compensate for the astigmatism otherwise present at the probe spots 391, 392, and 393.

[0051]

[0060] The source conversion unit 320 may further include a pre-bent micro-deflector array 323 with pre-bent micro-deflectors 323_1, 323_2, and 323_3 for bending the sub-beams 311, 312, and 313, respectively. The pre-bent micro-deflectors 323_1, 323_2, and 323_3 may bend the paths of the sub-beams onto the beamlet limiting aperture array 321. The sub-beam paths of incidence on the beamlet limiting aperture array 321 may be perpendicular to the orientation plane of the beamlet limiting aperture array 321. The focusing lens 310 may direct the paths of the sub-beams onto the beamlet limiting aperture array 321. The focusing lens 310 can focus the three sub-beams 311, 312, and 313 into a parallel beam along the primary electron optical axis 304, so that the sub-beams are perpendicularly incident on the source conversion unit 320, which can correspond to a beamlet limiting aperture array 321.

[0052]

[0061] The image forming element array 322, the aberration compensator array 324, and the pre-bent micro-deflector array 323 may include multiple layers of sub-beam steering devices, some of which may be forms or arrays (e.g., micro-deflectors, micro-lenses, or micro-astigmatists).

[0053]

[0062] In the source conversion unit 320, sub-beams 311, 312, and 313 of the primary electron beam 302 are deflected by micro-deflectors 322_1, 322_2, and 322_3, respectively, of the imaging element array 322 towards the primary electron optical axis 304. It is to be understood that the path of sub-beam 311 does not have to be deflected by micro-deflector 322_1, as the path of sub-beam 311 may already correspond to the electron optical axis 304 before reaching micro-deflector 322_1.

[0054]

[0063] The objective lens 331 focuses the sub-beams onto the surface of the sample 308, i.e., the objective lens 331 projects three virtual images onto the sample surface. The three images formed on the sample surface by the three sub-beams 311-313 form three probe spots 391, 392, and 393 on the sample surface. The deflection angles of the sub-beams 311-313 are adjusted by the objective lens 311 to reduce the off-axis aberrations of the three probe spots 391-393. The three deflected sub-beams consequently pass through or approach the front focus of the objective lens 331.

[0055]

[0064] At least some of the above components of Figures 2 and 3 may be referred to as manipulator arrays, or manipulators, either individually or in combination with each other, because they manipulate one or more charged particle beams or sub-beams.

[0056]

[0065] The multi-beam inspection tool includes a multi-beam charged particle device with a single charged particle source, which may be called a multi-beam charged particle optical device or a multi-beam charged particle system. The multi-beam charged particle device includes an illumination device and a projection device. The illumination device is capable of generating multiple charged particle beams from an electron beam of a source. The projection device projects the multiple charged particle beams towards a sample. At least a part of the sample surface is scanned with the multiple charged particle beams.

[0057]

[0066] With the multi-beam charged particle devices described above, several problems can be experienced that complicate the application of simultaneous operations to the sub-beams of the multi-beam.

[0058]

[0067] In order for each individual sub-beam path to be appropriately directed towards the sample surface, individual components may be provided for individually manipulating the path of each sub-beam, for example in a manipulator array. The applied manipulation may for example be a deflection of the path of the sub-beam. The manipulator array may for example be a manipulator array as described with reference to figures 2 to 4 and 6 of EP 2 715 768 A2.

[0059]

[0068] A requirement that must be met for the individual components to be able to properly apply steering to the sub-beams is that the steering does not introduce excessive aberrations. The degree of aberration depends on the uniformity of the electric field within the steering component, the fill factor of the steering component, and the magnitude of the electric field within the steering component. The magnitude of the electric field depends on the voltages applied to the electrodes within the steering component.

[0060]

[0069] The degree of aberration depends on the uniformity of the electric field through which the sub-beam paths pass. An ideal electric field across a component would be linear. However, in plan, the aperture is circular, and a linear electric field can only be approximated by providing multiple electrodes around the aperture and providing appropriately applied voltages at each electrode. The quality of the approximation of the achievable linear electric field improves as the number of electrodes used increases. However, increasing the number of electrodes in a component increases its size. Increasing the number of electrodes also increases the complexity of providing wiring and associated driver circuitry for all the electrodes of each component.

[0061]

[0070] The fill factor is the ratio of the diameter of the sub-beams in the manipulation component to the diameter of the aperture in the manipulation component. In plan, the most uniform electric field in the component is at the center of the aperture, and the electric field is least uniform toward the edge of the aperture. The degree of aberration increases as the fill factor increases, as the proportion of sub-beams away from the center of the aperture increases. For a given sub-beam diameter, the fill factor can be decreased by increasing the diameter of the aperture of the component.

[0062]

[0071] The degree of aberration also depends on the magnitude of the voltage applied in the component to create the electric field: at larger voltages, non-uniformities in the electric field have a larger effect on the sub-beam paths, which increases the aberration.

[0063]

[0072] At the very least, the above requirements of having a low fill factor and / or a large number of electrodes require that the individual components be relatively large, resulting in complex wiring and driver circuit requirements. If relatively large individual components are required to manipulate each sub-beam, then spatial limitations within the charged particle device impose constraints on both the number of sub-beams that can be provided and the density of the sub-beams.

[0064]

[0073] Furthermore, a relatively large voltage is required to generate the electric field in order to apply a relatively large deflection to some of the sub-beam paths, however, as explained above, the use of a relatively large voltage increases the degree of aberrations.

[0065]

[0074] An embodiment provides a manipulator device for simultaneously applying a substantially constant deflection to some or all of the paths of multiple sub-beams of a multi-beam.

[0066]

[0075] The manipulator device according to the embodiments can reduce at least some of the manipulation requirements (particularly the deflection requirements) of a manipulator array that includes individual components for each sub-beam. The manipulator device according to the embodiments can provide a main deflection of all deflected sub-beam paths. This reduces the complexity of providing a manipulator array and improves the control of the sub-beam paths in a charged particle device. The manipulator device according to the embodiments can apply a substantially constant deflection to a line of sub-beams and does not require complex control circuitry.

[0067]

[0076] When manipulator devices according to embodiments are used, the manipulator array is only required to apply fine deflections to the individual sub-beam paths. The components in the individual arrays are not required to apply large deflections, and therefore simpler component designs may be used that only need to apply relatively small voltages. Simpler component designs may include a smaller number of electrodes, thereby reducing the complexity of the wiring and driver requirements for each component. The use of lower voltages reduces the degree of aberrations compared to when larger voltages are used. This allows smaller individual components to be used per sub-beam, since for a given degree of aberration the fill factor of the components can be increased and the number of electrodes can be reduced. The use of smaller individual components in the manipulator array increases the density of the sub-beams and / or the number of sub-beams that can be supported.

[0068]

[0077] The manipulator device according to the embodiment is particularly suitable for providing a passive electro-optical manipulation device, such as a pre-bending manipulation of the path of a charged particle in a charged particle device. The pre-bending manipulation may include an applied deflection that is substantially invariant over a range of operating conditions. The pre-bending may converge the path of the charged particle beam. Another passive element is a collimator that collimates the path of the charged particle beam. A collimated multi-beam may be generated from converging or diverging sub-beam paths.

[0069]

[0078] 4 is a schematic diagram of a manipulator device according to an embodiment. FIG. 4 is a plan view of a multi-beam, which may be along a charged particle axis. The manipulator device includes a first electrode pair 402, a second electrode pair 403, and a third electrode pair 404. Between each of these parallel planar electrode pairs are paths of different lines of three sub-beams 401 of the multi-beam. Each parallel planar electrode pair may be referred to as a strip electrode.

[0070]

[0079] Each electrode may be a planar plate. Each electrode may be mechanically supported at each of its ends or at one of its ends. Each electrode may only be mechanically supported at one or both of its ends. Each electrode may be electrically connected at least at one of its ends. Each electrode may be metallic (such as a metal plate or a metallized or metallized surface). Each electrode may be, for example, a metal coating on the surface of the electrode's support structure or body. Each electrode pair may include two such planar plates arranged parallel to each other and opposite each other. An electric field E is applied between each electrode pair. For each electrode pair, an electric field is applied in a direction perpendicular to the surface of the electrode (i.e., the planar plate) and substantially perpendicular to the path of each sub-beam between the electrode pair. Each electrode pair may thereby electrostatically interact with multiple sub-beams passing between them, thereby deflecting the sub-beam paths.

[0071]

[0080] A charged particle multibeam contains multiple lines of sub-beams. Thus, a multibeam is a two-dimensional array of sub-beams, which can be a series of multiple lines of sub-beams. Each electrode pair is arranged to deflect the path of all the sub-beams in the entire line of sub-beams.

[0072]

[0081] The amount of deflection applied by each electrode pair to each line path of the sub-beam depends on the potential difference between the electrodes. Thus, the magnitude of deflection of a line path of the charged particle beam can be determined by the size of the potential difference applied between the parallel plates on either side of the line of the beam path. Thus, a relatively large deflection can be achieved by applying a larger potential difference between the opposing electrode surfaces.

[0073]

[0082] The potential difference between each electrode pair may be individually and separately controllable. This allows each of the multiple electrode pairs to apply a different amount of deflection to the path of the line of sub-beams. Thus, the amount of deflection applied across the array is configurable and actively controllable. In addition, the direction of the applied electric field may differ between the multiple electrode pairs. This allows the amount of deflection to the path of the line of sub-beams to be applied in opposite directions.

[0074]

[0083] In an embodiment, during operation, one or more electrode pairs in the manipulator array may be set to have zero potential difference between them. Thus, each electrode pair may deflect the path of a sub-beam in a line of sub-beams, but one or more of the electrode pairs may be operated such that no electric field is applied between the electrodes. Such electrode pairs do not deflect the path of the sub-beam traveling between them.

[0075]

[0084] FIG. 5 is a schematic diagram of a manipulator device according to an embodiment. FIG. 5 shows five separate lines of sub-beam paths. For each line, two of the sub-beam paths in that line are shown. For each line of sub-beams, there is a respective electrode pair between which the line of sub-beams travels. The electrodes are supported by electrode supports 501, 502, 503, 504, 505, and 506. Each electrode support may be mechanically supported at each of its ends or at one of its ends. Each electrode support may only be mechanically supported at one or both of its ends. Each electrode support may be made, for example, of glass or the material of the substrate from which the electrodes are made (e.g., silicon). The potential difference between each electrode pair may differ in magnitude and / or direction. An embodiment includes no potential difference between one or more of the electrode pairs. As shown in the figure, an example is between the central electrode pair (see E0). The applied potential differences between the electrode pairs are shown in FIG. 5 as E1, E2, E3, and E4. The magnitude of the electric field E1 is greater than that of E2, which in turn is greater than E0. Similarly, E4 is greater in terms of electric field magnitude than E3, which in turn is greater than E0. E3 and E4 have electric fields that appear to be directionally opposite to E1 and E2, respectively. In fact, E1 and E4 may have electric fields of similar or identical magnitudes, but in opposite directions, and E3 and E4 may have electric fields of similar or identical magnitudes, but in opposite directions. In an alternative arrangement, a potential difference may be applied to the center electrode pair such that E0 is non-zero.

[0076]

[0085] As shown in FIG. 5, the effect of the applied potential difference may be to generate a down-beam crossover point of the paths of the separate lines of the sub-beam. No potential difference (i.e., E0) is applied between the electrode pair through which the central line of the sub-beam passes. Thus, the path of the central line of the sub-beam is not substantially deflected by the electrode pair. In the figure, the potential difference E1 applied between the electrode pair through which the leftmost line of the sub-beam passes may have the same magnitude and opposite sign as the potential difference E4 applied between the electrode pair through which the rightmost line of the sub-beam passes. The potential difference E2 applied between the electrode pair through which the second leftmost line of the sub-beam passes may have the same magnitude and opposite sign as the potential difference E3 applied between the electrode pair through which the second rightmost line of the sub-beam passes. The magnitudes of the potential differences E1 and E4 may be greater than the potential differences E2 and E3 such that the paths of the leftmost and rightmost lines of the sub-beam are deflected more than the paths of the second leftmost and second rightmost lines of the sub-beam.

[0077]

[0086] A path of a first sub-beam in each line of sub-beams in the down beam from the manipulator may intersect with a path of the first sub-beam in the other line of sub-beams at substantially the same first down beam position. A path of a second sub-beam in each line of sub-beams may intersect with a path of another second sub-beam in the other line of sub-beams at substantially the same second down beam position. The first down beam position may be different from the second down beam position.

[0078]

[0087] Although FIG. 5 shows two sub-beams in each line of sub-beams, embodiments include where there are any number of sub-beams in each line of sub-beams.

[0079]

[0088] Although FIG. 5 shows five separate lines of sub-beams, embodiments include any number of lines of sub-beams and respective electrode pairs for each line of sub-beams.

[0080]

[0089] Embodiments also include where a potential difference applied to one or more of the electrode pairs causes the paths of two or more of the lines of the sub-beams to diverge instead of converge.

[0081]

[0090] In Figure 5, parallel structures between which the lines of sub-beams pass are shown diagrammatically. It is to be understood that these parallel structures represent both the electrodes between which the lines of sub-beams pass, and the support structures for the electrodes. The specific arrangement of how the electrodes are supported by the support structures may be according to a number of different techniques.

[0082]

[0091] As shown in Figures 4 and 5, the sub-beams travel only between adjacent electrodes in an electrode pair for deflecting the sub-beam paths. The sub-beams do not travel between adjacent electrodes if each of the adjacent electrodes is in a different electrode pair for deflecting the sub-beam paths. In the case of adjacent electrodes where each electrode is in a different electrode pair, the adjacent electrodes may be supported by a solid support structure such as a substrate as shown in Figure 5. Alternatively, adjacent electrodes may be separated by a gap as shown in Figure 4.

[0083]

[0092] Between each adjacent electrode, a high voltage shield may be provided on the electrode support structure to electrically insulate the ends of the electrodes that contact the support structure from each other.

[0084]

[0093] Embodiments also include where there are two or more sets of electrode pairs for deflecting the path of the line of sub-beams. Each set of electrode pairs may be a set of parallel plate electrode pairs as described above with reference to Figures 4 and 5. Each set of electrode pairs may be provided at a different position along the charged particle axis, i.e., the path of the multi-beam.

[0085]

[0094] Within each set of electrode pairs (or array of electrode pairs), and for which electrode pairs there is an applied electric field, all of the applied electric fields may be aligned perpendicular to the same axis as the set of electrode pairs. The applied potential difference between the electrode pairs may result in some of the applied electric fields being in opposite directions to each other, but the applied electric fields are still aligned perpendicular to the same axis. The parallel electrode pairs within each set are aligned parallel to the axis of the set. As shown in FIG. 5, the potential difference applied between opposing parallel plate pairs may depend on the distance from the midpoint of the array. For example, the electric field may be proportional to the distance from the midpoint of the array of parallel plates. The applied deflection may therefore steer the beam path of the down beam of the manipulator array to a point where it intersects the beam path at the respective line positions where the lines of the paths intersect each other.

[0086]

[0095] An embodiment includes having multiple sets of electrode pairs arranged in series along the multi-beam path. The axes of two or more of the sets may be aligned in different directions. The axes of all of the sets may be aligned in different directions. If the axes of two or more of the sets are aligned in different directions, the differently aligned sets apply differently induced deflections to the paths of the sub-beams of the multi-beam. Thus, having more than one set of electrode pairs increases the amount of control that can be applied to the paths of the sub-beams.

[0087]

[0096] As shown in Figure 6, there may be a first set or array of electrode pairs 601 and a second set or array of electrode pairs 602. These two arrays may have parallel plate pairs aligned perpendicular to each other and also to the multi-beam path. The first and second sets of electrode pairs are provided at different locations along the path 603 of the multi-beam. The respective axes of the first and second sets of electrode pairs are aligned in different directions. Although Figure 6 shows two sets of electrodes, embodiments include there being any number of sets of electrodes.

[0088]

[0097] Although the arrays of electrodes have been described as being orthogonal to one another (in orthogonal planes), they may be at any relative angle to one another, so long as the axes represent the axes used by the invention at the time of discussion or the axes that were known when the discussion was contemplated.

[0089]

[0098] Embodiments include multiple different arrangements of the sets of electrode pairs as required so that each set of electrode pairs can deflect a different arrangement of the lines of sub-beams.

[0090]

[0099] FIG. 7A is a schematic plan view (i.e., along the charged particle optical axis) of the sub-beams in a line arrangement of the sub-beams. The illustrated arrangement of the sub-beams may be referred to as a hexagonal arrangement, since substantially all of the sub-beams are located at the vertices of multiple hexagonal rings. The arrangement of the beams may follow a hexagonal close-packed arrangement, which may be a desirable and common form of two-dimensional array. The sub-beams are arranged in multiple different lines. With respect to the horizontal and vertical axes shown in FIG. 7A, all the sub-beams are aligned both in a line parallel to the horizontal axis and in a line parallel to the vertical axis. The sub-beams are also aligned in a line oblique to the horizontal and vertical axes. In one variation, the array may be optimized for scanning configurations by having the beam arrangement adjusted by offsetting, shifting, or skewing the beam arrangement, for example to prevent overlapping of the sub-beam paths.

[0091]

[0100] Thus, all sub-beams in a multi-beam arrangement can be deflected by one set of electrode pairs with axes aligned with the axes of the pattern of the multi-beam arrangement, which in the case of the arrangement shown in Figure 7A are horizontal, vertical and either along a diagonal to the horizontal axis or along a diagonal to the vertical axis.

[0092]

[0101] FIG. 7B illustrates how multiple sets of electrode pairs may be aligned according to an embodiment having a hexagonal beam arrangement. Each array of electrode pairs is at a different location along the path of the multi-beam. That is, multiple arrays of electrode pairs may be arranged consecutively along the multi-beam path. As shown in FIG. 7B, there may be a first set, a second set, and a third set of electrode pairs. The axis of the first set may be aligned parallel to the horizontal axis, the axis of the second set may be aligned along one diagonal, and the axis of the third set may be aligned along the other diagonal. When three sets of electrode pairs with such alignment are used, the pitch, i.e., spacing, between different electrode pairs in each set may be smaller than the pitch required when only two orthogonally aligned sets of electrode pairs are used. As shown in FIG. 7B, the electrode pairs in each set may also be slightly misaligned with respect to each other. That is, each electrode pair in a set is aligned in the same direction and has the same length as each other. However, the ends of each electrode pair are not aligned with one another in a direction orthogonal to the direction in which each electrode pair in a set is aligned.

[0093]

[0102] The use of multiple differently aligned sets of electrode pairs allows for improved control over the path directions of the sub-beams of a multi-beam, and further allows the array of electrode pairs to be easily incorporated into an electron-optical architecture designed for a hexagonal beam geometry.

[0094]

[0103] It should be noted that deflection of a charged particle beam without counter deflection can induce aberrations in the deflected charged particle beam. In this arrangement, sub-beams further away from the electron optical axis may be deflected more and therefore exhibit larger aberrations. Thus, such a multi-beam may contain aberrations after the manipulators of the multiple arrays of parallel plates direct the charged particle sub-beams to a focal point. These aberrations can be corrected by providing the sub-beams to be manipulated by one or more astigmatism correctors arranged in the path of the multi-beam.

[0095]

[0104] Embodiments include other arrangements of the sub-beams of the multi-beam. When viewed along the charged particle optical axis, the positions of the sub-beams in the multi-beam may substantially correspond to vertices of a substantially square grid, a substantially diamond-shaped grid, a substantially skewed square grid, a substantially shifted square grid, a substantially squashed square grid, a substantially offset square grid, a substantially hexagonal grid, a substantially shifted hexagonal grid, a substantially squashed hexagonal grid, a substantially offset hexagonal grid, and / or a substantially skewed hexagonal grid. The arrangement of pairs of planar electrode surfaces of each manipulator device may be determined according to the arrangement of the sub-beams of the multi-beam such that each electrode pair is arranged to deflect a line of the sub-beam.

[0096]

[0105] Specifically, if the positions of the sub-beams in the multi-beam correspond to the vertices of a substantially square grid, two sets of electrode pairs may be provided. These may be a first set of electrode pairs 601 and a second set of electrode pairs 602. The first and second electrode pairs may be aligned in orthogonal directions such that all sub-beam paths can be deflected towards the charged particle optical axis and a single crossover location. Alternatively, if the positions of the sub-beams in the multi-beam correspond to the vertices of a substantially hexagonal grid, three sets of electrode pairs may be provided. These may be aligned in different directions with the same angular spacing between all adjacent alignments such that all sub-beam paths can be deflected towards the charged particle optical axis and a single crossover location. In such an arrangement, the multi-beam manipulator may have several arrays of parallel plates arranged in series, each array corresponding to and aligned with a different axis of the beam arrangement of the multi-beam.

[0097]

[0106] The embodiment also includes positions of the sub-beams in the multi-beam that correspond to the vertices of a substantially hexagonal grid (although only two orthogonally aligned sets of electrode pairs are provided). In FIG. 7B there is a square showing a subset of the sub-beams. It is evident from the sides of the square that, despite the basic hexagonal pattern of the sub-beams, the sub-beams are still linearly aligned in orthogonal directions, which in the representation shown in FIG. 7B are horizontal and vertical lines. For example, based on the representation shown in FIG. 7B, all of the horizontal lines of the sub-beams may be deflected by a first set of electrode pairs, and all of the vertical lines of the sub-beams may be deflected by a second set of electrode pairs. Note that in the first set of electrode pairs, the pitch, i.e., the spacing, between adjacent electrodes arranged to deflect different lines of the sub-beams is greater than the corresponding pitch in the second set of electrode pairs. If the positions of the sub-beams correspond to a regular hexagonal grid, the proportional difference in pitch may be ((√3) / 2). However, embodiments include reducing and / or increasing this pitch difference by using sub-beams arranged in a substantially offset, shifted, skewed, and / or squashed hexagonal grid.

[0098]

[0107] Thus, the embodiments provide one or more multibeam manipulator devices for deflecting paths of a plurality of sub-beams of a charged particle multi-beam. A main deflection to the paths of the sub-beams can be applied by each multibeam manipulator device. The sub-beams are arranged in an array in which the sub-beams are arranged in a plurality of lines. Each multibeam manipulator device includes a set of electrodes including a plurality of pairs of parallel planar electrode surfaces. Each electrode pair includes a first planar electrode surface arranged along one side of one of the lines of sub-beams and a second planar electrode surface parallel to the first planar electrode surface and arranged along the opposite side of said one of the lines of sub-beams. Each pair of parallel planar electrode surfaces is configured to electrostatically interact with the entire line of sub-beams of the multi-beam so as to apply a deflection amount to the paths of the sub-beams. Within a set of sets of electrodes, all electrode pairs can deflect the paths of the sub-beams of the multi-beam in the same direction. Alternatively, one or more electrode pairs may deflect the path of the sub-beam in an opposite direction to one or more other electrode pairs. One or more electrode pairs in a set may apply no deflection at all to the path of the sub-beam.

[0099]

[0108] The electrode pairs in each multi-beam manipulator device may be arranged to apply different amounts of deflection to the sub-beams.

[0100]

[0109] All electrode pairs in each multi-beam manipulator device may be configured to apply a deflection to the path of the sub-beam by electrostatically interacting with the entire line of sub-beams of the multi-beam. Alternatively, one or more (but not all) of the electrode pairs in each multi-beam manipulator device may be configured to apply a deflection to the path of the sub-beam by electrostatically interacting with the entire line of sub-beams of the multi-beam.

[0101]

[0110] The lines of the sub-beams in the multi-beam may all be parallel to each other, and all electrode pairs in each multi-beam manipulator device may be configured to be able to deflect all sub-beams in the multi-beam.

[0102]

[0111] All electrode pairs in each multi-beam manipulator device may be configured such that each electrode pair is capable of deflecting only one line of sub-beams of the multi-beam. Alternatively, one or more of the electrode pairs in each multi-beam manipulator device may be configured such that they are capable of deflecting two or more lines of sub-beams of the multi-beam.

[0103]

[0112] All electrode pairs within each multi-beam manipulator device may be configured such that they are disposed in the same plane as each other, which plane is substantially perpendicular to the charged particle optical axis of the multi-beam (i.e., the path of the multi-beam).

[0104]

[0113] All electrode pairs within each multi-beam manipulator device may be configured such that an applied electric field between each electrode pair is substantially perpendicular to the charged particle optical axis. The applied electric field between each electrode pair may be substantially constant during operation of the multi-beam manipulator device.

[0105]

[0114] Each electrode pair in each multibeam manipulator device may be configured such that the applied electric field differs in direction and / or magnitude from the electric field applied by the other electrode pairs. Thus, the deflection applied to any one of the paths of the lines of the sub-beams of the multibeam may differ in direction and / or magnitude from the deflection applied by any other one of the paths of the lines of the sub-beams. Each applied electric field may be equal in magnitude and opposite in direction to the applied electric field by another applied electric field. The applied electric fields in the multibeam manipulator device may be arranged to deflect the paths of the lines of the sub-beams such that the path of each line of the sub-beam intersects with the paths of every other line of the sub-beams that are in the down beam from the multibeam manipulator device. In one arrangement, the applied electric field may depend on the distance of each parallel plate pair from the midpoint of the array, and additionally or alternatively, the direction of the electric field applied between the parallel plate pairs may depend on the orientation of the pair relative to the midpoint of the array. The midpoint may correspond to the location of the electron optical axis in a direction across the array of parallel plates (as opposed to along the lines of the beam for a particular array).

[0106]

[0115] As mentioned above, embodiments also include a multi-beam manipulator arrangement. The multi-beam manipulator arrangement includes multiple multi-beam manipulator devices arranged at different positions along the charged particle optical axis and / or the path of the multi-beam. The axes of each multi-beam manipulator device may be aligned in different directions. For example, the multi-beam manipulator arrangement may include multi-beam manipulator devices with axes aligned at right angles to each other and / or multi-beam manipulator devices with axes aligned at 30 degrees, 60 degrees, 90 degrees, 120 degrees, or 150 degrees to each other.

[0107]

[0116] A multi-beam charged particle device such as an illuminator may include a charged particle source arranged to emit a charged particle beam and a multi-beam generator arranged to generate a charged particle multi-beam based on the beam. The charged particle device may include a multi-beam manipulator device and / or a multi-beam manipulator arrangement according to the above embodiments capable of manipulating a line of sub-beams of the charged particle multi-beam.

[0108]

[0117] The charged particle optical axis of a multi-beam charged particle device may be defined as parallel to the average direction of the sub-beams of the multi-beam output from the multi-beam generator.

[0109]

[0118] The multi-beam charged particle device may further include one or more manipulators for manipulating the sub-beam and / or the path of the sub-beam for each of the sub-beams. Thereby, all of the sub-beams or sub-beam paths may be individually manipulated by the manipulator array. The manipulator array may be configured to substantially collimate the paths of the sub-beams of the multi-beam, or to apply any other type of manipulation. Each of the individual manipulators in the manipulator array may include, for example, a quadrupole, octapole, or dodeca-pole electrode arrangement. As described above, the use of one or more manipulator devices according to the embodiments may result in the manipulators only being required to apply fine manipulation to the sub-beam paths, which may provide several advantages, such as a simplified design and implementation of the manipulator array, as well as an increased number and density of individual manipulators in the manipulator array. The fine manipulation may be achieved at a low operating voltage, and wiring and routing requirements are reduced.

[0110]

[0119] Individual manipulators for manipulating the sub-beams may be arranged in a manipulator array, as shown in Figure 8. Figure 8 shows a manipulator array for manipulating 25 sub-beams arranged in a square grid. The manipulator array may include different numbers and arrangements of manipulators as needed for operation with the number and arrangement of sub-beams of the multi-beam.

[0111]

[0120] FIG. 9 is a schematic diagram showing a cross section in the zy plane through a portion of a charged particle device. As shown in FIG. 9, 902 can be a manipulator device according to an embodiment aligned along the x-axis. 904 can be a manipulator device according to an embodiment aligned along the y-axis. A manipulator array may be provided in the multi-beam path at one or more of positions 901, 903, or 905. Thus, more than one manipulator array may be provided. The amount of aberration caused by a manipulator in a manipulator array may be minimal if all of the sub-beam paths through the manipulator are substantially perpendicular to the plane of the manipulator array. This may be an advantage to position one or more of the manipulator arrays at such a position along the charged particle axis, for example, all of the manipulator arrays may be located in the up beam of the manipulator device (e.g., at position 901 in FIG. 9).

[0112]

[0121] The portion of the charged particle device shown in Figure 9 is arranged to focus multiple sub-beams to a focal point. Due to the focusing of the sub-beams, the pitch, or separation, between adjacent components in the manipulator array may be smaller in the y-direction for the manipulator array positioned at 903 than for the manipulator array positioned at 901. Similarly, the pitch between adjacent components in the manipulator array may be smaller in the x-direction for the manipulator array positioned at 905 than for the manipulator arrays positioned at 901 and / or 903.

[0113]

[0122] The drive signals of the manipulator device and / or the manipulator array may be varied to control the position of the focal spot of the sub-beam along the charged particle optical axis and / or to control the position of the focal spot in the xy plane. The manipulator device may also be configured to apply corrections for errors in the x and / or y positions of the sub-beams.

[0114]

[0123] The embodiment also includes the sub-beams entering the portion of the charged particle device diverging such that the multi-beam is a diverging beam. The manipulator device may be arranged to collimate the diverging sub-beams. In this configuration, the pitch between the components of the manipulator array may alternatively increase with the down-beam location of the manipulator array.

[0115]

[0124] It should be noted that Figure 9 is not drawn to scale. In a typical implementation of a charged particle device, the z-separation between each of the manipulator arrays and manipulator devices may be a few millimeters. The z-distance to the focal points of the sub-beams may be several hundred millimeters from the location of the manipulator devices.

[0116]

[0125] The embodiment also includes providing one or more astigmatism correctors in the path of the multi-beam. An astigmatism corrector array having the structure of a manipulator array may be positioned at one or more of locations 901, 903, and 905 of FIG. 9 and / or in the up beam and / or down beam of this portion of the charged particle device. Each astigmatism corrector element is a multi-pole electrode device. Each astigmatism corrector may include a shield for protection. This shield may be immediately up beam of the array of astigmatism corrector elements to protect the astigmatism corrector elements from stray electrons. This shield may take the form of a substrate having apertures corresponding at appropriate locations to the apertures of the astigmatism corrector array.

[0117]

[0126] Embodiments include any number and arrangement of sub-beams within a multi-beam, for example, the arrangement of sub-beams of a multi-beam may be n x m, where n is 3, 11, or 1000 or more, and m is 3, 11, or 1000 or more.

[0118]

[0127] The height, ie the length along the charged particle optical axis, of each electrode of the manipulator device may be several hundred micrometers, such as about 300 μm.

[0119]

[0128] The space between the two electrodes of the electrode pair may be from about 50 μm to several hundred micrometers.

[0120]

[0129] Each electrode may be made, for example, from metallized silicon or heavily doped silicon.

[0121]

[0130] The embodiments include several modifications and variations to the above techniques.

[0122]

[0131] The multi-beam charged particle device may be a component of an inspection (or metro-inspection) tool, or part of an electron beam lithography tool. Multi-beam charged particle devices according to embodiments may be used in a number of different applications, including not only SEM but also electron microscopy in general, and lithography.

[0123]

[0132] Embodiments include a multi-beam inspection and / or metrology tool including a manipulator device according to the embodiments described above. The manipulator device may be part of a scanning device arranged to project the charged particle multi-beams onto the sample. The multi-beam inspection tool may include a detector arranged to detect charged particles (such as secondary electrons) received from the illuminated sample.

[0124]

[0133] The embodiments also include a multi-beam lithography tool including a manipulator device as described above according to the embodiments.

[0125]

[0134] In particular, a multi-beam charged particle apparatus may include both a manipulator device according to an embodiment and any of the components of the apparatus described above with reference to Figures 1-3.

[0126]

[0135] A multi-beam charged particle device may include a single charged particle source as shown in Figures 1-3. Alternatively, a multi-beam charged particle device may include multiple charged particle sources. There may be a separate column for each source and a manipulator device according to an embodiment provided in each column. Alternatively, a multi-beam charged particle device may include multiple charged particle sources and only one column. One or more manipulator devices according to an embodiment may be provided in a single column.

[0127]

[0136] Throughout the embodiments, a charged particle optical axis is described. This axis represents the path of the charged particles through and output from the illumination device. All sub-beams of the output multi-beam may 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 illumination device.

[0128]

[0137] The embodiment includes the following description.

[0129]

[0138] According to a first aspect of the invention, there is provided a multibeam manipulator device configured to act on paths of a plurality of sub-beams of a charged particle multibeam, thereby deflecting a plurality of sub-beam paths, the sub-beams being arranged in an array in which the sub-beams are arranged in a plurality of lines, the multibeam manipulator device comprising a set of electrodes comprising a plurality of parallel planar electrode surface pairs, a first parallel planar electrode surface pair in the set comprising a first planar electrode surface arranged along one side of one of the lines of sub-beams and a second planar electrode surface parallel to the first planar electrode surface and arranged along an opposite side of said one of the lines of sub-beam paths, the second parallel planar electrode surface pair in the set comprising a first planar electrode surface arranged along one side of said one of the lines of sub-beam paths, the second planar electrode surface pair arranged along one side of said one of the lines of sub-beam paths, the a first planar electrode surface arranged along one side of another of the lines of sub-beam paths and a second planar electrode surface parallel to the first planar electrode surface and arranged along an opposite side of the other of the lines of sub-beam paths, the first pair of parallel planar electrode surfaces configured to electrostatically interact with the entire line of sub-beams of the multi-beam to apply a first deflection amount to the paths of the sub-beams in a first direction and the second pair of parallel planar electrode surfaces configured to electrostatically interact with the entire line of sub-beams of the multi-beam to apply a second deflection amount to the paths of the sub-beams in a second direction, the first direction being opposite to the second direction.

[0130]

[0139] Preferably, the magnitude of the first deflection amount is different from the magnitude of the second deflection amount.

[0131]

[0140] Preferably, each pair of parallel planar electrode surfaces in the set is configured to electrostatically interact with an entire line of sub-beams of the multi-beam, thereby applying a deflection to the paths of the sub-beams.

[0132]

[0141] Preferably, the plurality of parallel planar electrode surface pairs are configured to be capable of deflecting all of the lines of sub-beams in the array, the lines of sub-beams being substantially parallel to one another across the array.

[0133]

[0142] Preferably, the plurality of parallel planar electrode surface pairs are configured to be capable of deflecting at least two but not all of the lines of the sub-beams in the array, the lines of the sub-beams being substantially parallel to each other across the array.

[0134]

[0143] Preferably, each pair of parallel planar electrode surfaces in the set is configured such that it is capable of deflecting only one line of sub-beams of the multi-beam.

[0135]

[0144] Preferably, all of the planar-parallel electrode surface pairs are disposed in the same plane as each other, the plane being substantially perpendicular to the charged particle optical axis.

[0136]

[0145] Preferably, each parallel planar electrode surface pair is configured to apply an electric field between its first and second planar surfaces to electrostatically deflect all of the paths of the sub-beams in the line of the sub-beams, the applied electric field being substantially perpendicular to the charged particle optical axis.

[0137]

[0146] Preferably, in use, each parallel planar electrode surface pair applies a substantially constant electric field between its first and second planar surfaces to deflect all paths of the sub-beams in the line of sub-beams.

[0138]

[0147] Preferably, each planar-parallel electrode surface pair is configured to apply an electric field which differs in direction and / or magnitude from the electric fields applied by the other planar-parallel electrode surface pairs, such that the applied deflection for each line of sub-beams of the multi-beam differs in direction and / or magnitude.

[0139]

[0148] Preferably, for each of one or more parallel planar electrode surface pairs, the electric field applied by the parallel planar electrode surface pair is equal in magnitude and opposite in direction to the electric field applied by another parallel planar electrode surface pair.

[0140]

[0149] Preferably, when viewed along the charged particle optical axis, the positions of the sub-beams within the multi-beam substantially correspond to the vertices of a substantially square grid, a substantially diamond-shaped grid, and / or a substantially skewed or shifted square grid.

[0141]

[0150] Preferably, when viewed along the charged particle optical axis, the positions of the sub-beams within the multi-beam substantially correspond to the vertices of a substantially hexagonal grid and / or a substantially skewed or shifted hexagonal grid.

[0142]

[0151] According to a second aspect of the present invention there is provided a multi-beam manipulator arrangement comprising a first multi-beam manipulator device according to the first aspect and one or more further multi-beam manipulator devices, each of the one or more further multi-beam manipulator devices being a multi-beam manipulator device according to the first aspect, wherein each multi-beam manipulator device is arranged at a different position along a charged particle optical axis of the multi-beam manipulator arrangement.

[0143]

[0152] Preferably, the planar electrode surface pairs are aligned in the same direction within each multi-beam manipulator device and in different directions in each multi-beam manipulator device.

[0144]

[0153] Preferably, the multi-beam manipulator arrangement includes a second multi-beam manipulator device, the planar electrode surface pair in the second multi-beam manipulator device being aligned substantially perpendicular to and downpath with the first multi-beam manipulator device.

[0145]

[0154] Preferably, the multi-beam manipulator arrangement includes a second multi-beam manipulator device and the multi-beam manipulator arrangement includes a third multi-beam manipulator device, and the planar electrode surface pairs in the first multi-beam manipulator device, the second multi-beam manipulator device and the third multi-beam manipulator device are aligned in different directions.

[0146]

[0155] Preferably, the array includes three different sets of lines, each set of lines aligned in a different direction.

[0147]

[0156] Preferably, for at least one of the multi-beam manipulator devices, one or more pairs of parallel electrode surfaces are configured to deflect the path of each line of the sub-beam so that the path of each line of the sub-beam intersects with the paths of all other lines of the sub-beam that are down-beam from at least one of the multi-beam manipulator devices.

[0148]

[0157] According to a third aspect of the present invention there is provided a charged particle system comprising a charged particle source arranged to emit a beam, a multibeam generator arranged to generate a multibeam based on the beam, the multibeam comprising a plurality of sub-beams, and one of a multibeam manipulator device according to the first aspect or a multibeam manipulator arrangement according to the second aspect configured to manipulate paths of the sub-beams of the multibeam generated by the multibeam generator.

[0149]

[0158] Preferably, the charged particle optical axis is defined as parallel to the average direction of the sub-beams of the multibeam output from the multibeam generator.

[0150]

[0159] Preferably, the system further comprises, for each of the sub-beams, one or more manipulators for manipulating the sub-beam paths such that the paths of the sub-beams can be individually manipulated.

[0151]

[0160] Preferably, the manipulator for manipulating the sub-beams is configured to substantially collimate the sub-beam paths of the multi-beam.

[0152]

[0161] Preferably, the charged particles are electrons.

[0153]

[0162] According to a fourth aspect of the present invention there is provided an electron beam inspection tool including a charged particle system according to the third aspect.

[0154]

[0163] According to a fifth aspect of the present invention there is provided an electron beam lithography tool including a charged particle system according to the third aspect.

[0155]

[0164] According to a sixth aspect of the present invention, there is provided a multibeam manipulator device configured to act on a plurality of sub-beam paths of a charged particle multibeam to deflect the plurality of sub-beam paths, the sub-beams being arranged in an array in which the sub-beams are arranged in a series of lines, the multibeam manipulator device comprising a plurality of parallel planar electrode surface pairs, a first parallel planar electrode surface pair comprising two opposing planar parallel electrode surfaces arranged on either side along at least one of the lines of the sub-beams and a second parallel planar electrode surface pair comprising two opposing planar parallel electrode surfaces arranged on either side along at least another one of the lines of the sub-beams, the first parallel planar electrode surface pair and the second parallel planar electrode surface pair extending across the multibeam to intersect the array and configured, in operation, to electrostatically interact with each sub-beam path in the line between the surface pairs.

[0156]

[0165] According to a seventh aspect of the present invention, there is provided a multibeam manipulator configured to manipulate an array of sub-beam paths of a charged particle multibeam, the sub-beams being arranged in lines in the array, the lines being in at least two different line directions, the multibeam manipulator device comprising several deflector devices corresponding to a number of line directions in the array and arranged at different positions on the path of the multibeam, each deflector device comprising a plurality of parallel planar electrode surface pairs, the parallel planar electrode surfaces of each deflector device being aligned with different line directions, the plurality of parallel planar electrode surface pairs being arranged on either side along at least one of the lines of the sub-beams .... A multi-beam manipulator is provided comprising: a first parallel planar electrode surface pair including two opposing planar-parallel electrode surfaces; and a second parallel planar electrode surface pair including two opposing planar-parallel electrode surfaces arranged on either side along at least another one of the lines of sub-beams, where the at least another one of the lines of sub-beams is parallel to at least one of the lines of sub-beams, the first parallel planar electrode surface pair and the second parallel planar electrode surface pair extending across the multi-beam to intersect the array and configured, in operation, to electrostatically interact with each sub-beam path in the line between the surface pairs.

[0157]

[0166] According to an eighth aspect of the present invention, there is provided a multibeam manipulator configured to manipulate an array of sub-beam paths of a charged particle multibeam, the sub-beams being arranged in lines in the array, the lines being in at least two different line directions, the multibeam manipulator device comprising a number of deflector devices corresponding to the number of line directions in the array and positioned along the multibeam paths, each deflector device comprising a plurality of planar-parallel opposing electrode surfaces, the planar-parallel electrode surfaces of each deflector device being aligned in different line directions, the plurality of parallel planar electrode surface pairs comprising at least two opposing planar-parallel electrode surface pairs, each opposing planar-parallel surface pair being configured to cross across the multibeam array on either side of another at least one line of the sub-beam paths such that, in operation, each opposing planar-parallel electrode surface pair electrostatically interacts with all of the sub-beam paths in a respective at least one line between said surfaces.

[0158]

[0167] Preferably, the multi-beam manipulator is configured to deflect the sub-beams to a focal point.

[0159]

[0168] According to a ninth aspect of the present invention there is provided a method of deflecting paths of a plurality of sub-beams of a charged particle multi-beam, the sub-beams being arranged in an array in which the sub-beams are arranged in a plurality of lines, the method comprising: electrostatically interacting with an entire first line of sub-beams of the multi-beam such that a first deflection amount is applied to the paths of the sub-beams in a first direction; and electrostatically interacting with an entire second line of sub-beams of the multi-beam such that a second deflection amount is applied to the paths of the sub-beams in a second direction, the first direction being opposite to the second direction.

[0160]

[0169] While the invention has been described in connection with various embodiments, other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

[0161]

[0170] The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made as described without departing from the scope of the claims set forth below.

[0162]

[0171] Disclosed in the placement according to the following provisions.

[0163]

[0172] Clause 1: A multibeam manipulator device configured to deflect a plurality of sub-beam paths by acting on paths of a plurality of sub-beams of a charged particle multibeam, the sub-beams being arranged in an array in which the sub-beams are arranged in a plurality of lines, the multibeam manipulator device comprising a set of electrodes including a plurality of parallel planar electrode surface pairs;

[0173] a first pair of parallel planar electrode surfaces in the set includes a first planar electrode surface disposed along one side of one of the lines of sub-beams and a second planar electrode surface parallel to the first planar electrode surface and disposed along an opposite side of said one of the lines of sub-beam paths;

[0174] a second pair of parallel planar electrode surfaces in the set includes a first planar electrode surface disposed along one side of another one of the lines of sub-beam paths and a second planar electrode surface parallel to the first planar electrode surface and disposed along an opposite side of the other one of the lines of sub-beam paths;

[0175] a first pair of parallel planar electrode surfaces configured to electrostatically interact with an entire line of sub-beams of the multi-beam such that a first deflection amount can be applied to paths of the sub-beams in a first direction;

[0176] a second pair of parallel planar electrode surfaces configured to electrostatically interact with an entire line of sub-beams of the multi-beam so as to apply a second deflection amount to the paths of the sub-beams in a second direction;

[0177] A multi-beam manipulator device, wherein the first direction is opposite to the second direction.

[0164]

[0178] Clause 2: A multi-beam manipulator device as described in clause 1, wherein the magnitude of the first deflection amount is different from the magnitude of the second deflection amount.

[0165]

[0179] Clause 3: A multi-beam manipulator device as described in clause 1 or 2, wherein each pair of parallel planar electrode surfaces in the set is configured to apply a deflection to the path of a sub-beam by electrostatically interacting with an entire line of sub-beams of the multi-beam.

[0166]

[0180] Clause 4: A multi-beam manipulator device described in any one of clauses 1 to 3, wherein a plurality of parallel planar electrode surface pairs are configured to deflect all of the lines of sub-beams in the array, the lines of sub-beams being substantially parallel to each other across the array.

[0167]

[0181] Clause 5: A multi-beam manipulator device described in any one of clauses 1 to 3, wherein a plurality of parallel planar electrode surface pairs are configured to deflect at least two but not all of the lines of the sub-beams in the array, the lines of the sub-beams being substantially parallel to each other across the array.

[0168]

[0182] Clause 6: A multi-beam manipulator device described in any one of clauses 1 to 5, wherein each pair of parallel planar electrode surfaces in the set is configured to be capable of deflecting only one line of sub-beams of the multi-beam.

[0169]

[0183] Clause 7: A multi-beam manipulator device described in any one of clauses 1 to 6, wherein all of the parallel planar electrode surface pairs are arranged in the same plane as each other, the plane being substantially perpendicular to the charged particle optical axis.

[0170]

[0184] Clause 8: A multi-beam manipulator device described in any one of clauses 1 to 7, wherein each parallel planar electrode surface pair is configured to apply an electric field between its first and second planar surfaces to electrostatically deflect all of the paths of the sub-beams in the line of the sub-beams, the applied electric field being substantially perpendicular to the charged particle optical axis.

[0171]

[0185] Clause 9: A multi-beam manipulator device described in any one of clauses 1 to 8, wherein, in use, each parallel planar electrode surface pair applies a substantially constant electric field between its first and second planar surfaces to deflect all paths of the sub-beam in the line of the sub-beam.

[0172]

[0186] Clause 10: A multi-beam manipulator device described in any one of clauses 1 to 9, wherein each parallel planar electrode surface pair is configured to apply an electric field which differs in direction and / or magnitude from the electric fields applied by other parallel planar electrode surface pairs, such that the applied deflection for each line of sub-beams of the multi-beam differs in direction and / or magnitude.

[0173]

[0187] Clause 11: A multi-beam manipulator device described in any one of clauses 1 to 10, wherein for each of one or more parallel planar electrode surface pairs, the electric field applied by the parallel planar electrode surface pair is equal in magnitude and opposite in direction to the electric field applied by another parallel planar electrode surface pair.

[0174]

[0188] Clause 12: A multi-beam manipulator device described in any one of clauses 1 to 11, wherein, when viewed along the charged particle optical axis, the positions of the sub-beams within the multi-beam substantially correspond to the vertices of a substantially square grid, a substantially diamond-shaped grid, and / or a substantially distorted or shifted square grid.

[0175]

[0189] Clause 13: A multi-beam manipulator device described in any one of clauses 1 to 11, wherein, when viewed along the charged particle optical axis, the positions of the sub-beams within the multi-beam substantially correspond to vertices of a substantially hexagonal grid and / or a substantially distorted or shifted hexagonal grid.

[0176]

[0190] Clause 14: A multi-beam manipulator arrangement comprising a first multi-beam manipulator device as described in any one of clauses 1 to 13 and one or more further multi-beam manipulator devices, each of the one or more further multi-beam manipulator devices being a multi-beam manipulator device as described in any one of clauses 1 to 13, wherein each multi-beam manipulator device is positioned at a different position along a charged particle optical axis of the multi-beam manipulator arrangement.

[0177]

[0191] Clause 15: A multi-beam manipulator arrangement as described in clause 14, wherein the planar electrode surface pairs are aligned in the same direction within each multi-beam manipulator device and in different directions at each multi-beam manipulator device.

[0178]

[0192] Clause 16: A multi-beam manipulator arrangement as described in clause 14 or 15, wherein the multi-beam manipulator arrangement includes a second multi-beam manipulator device, and a pair of planar electrode surfaces in the second multi-beam manipulator device are aligned substantially perpendicular to and in the downpath relative to the first multi-beam manipulator device.

[0179]

[0193] Clause 17: A multi-beam manipulator arrangement as described in Clause 14 or 15, wherein the multi-beam manipulator arrangement includes a second multi-beam manipulator device and the multi-beam manipulator arrangement includes a third multi-beam manipulator device, and the planar electrode surface pairs in the first multi-beam manipulator device, the second multi-beam manipulator device and the third multi-beam manipulator device are aligned in different directions, respectively.

[0180]

[0194] Clause 18: A multi-beam manipulator arrangement as described in clause 17, wherein the array comprises three different sets of lines, each set of lines being aligned in a different direction.

[0181]

[0195] Clause 19: A multi-beam manipulator arrangement as described in any one of clauses 14 to 18, wherein, for at least one of the multi-beam manipulator devices, one or more pairs of parallel electrode surfaces are configured to deflect the path of each line of the sub-beam such that the path of each line of the sub-beam intersects with the paths of all other lines of the sub-beam that are in the down beam from at least one of the multi-beam manipulator devices.

[0182]

[0196] Clause 20: A charged particle system comprising: a charged particle source arranged to emit a beam; a multibeam generator arranged to generate a multibeam based on the beam, the multibeam comprising a plurality of sub-beams; and a multibeam manipulator device described in any one of clauses 1 to 13 or one of the multibeam manipulator arrangements described in any one of clauses 14 to 19 configured to manipulate paths of the sub-beams of the multibeam generated by the multibeam generator.

[0183]

[0197] Clause 21: The charged particle system of clause 20, wherein the charged particle optical axis is defined as being parallel to the average direction of the sub-beams of the multibeam output from the multibeam generator.

[0184]

[0198] Clause 22: A charged particle system as described in clause 20 or 21, wherein the system further comprises one or more manipulators for manipulating the sub-beam paths, for each of the sub-beams, such that the paths of the sub-beams can be manipulated individually.

[0185]

[0199] Clause 23: A charged particle system according to any one of clauses 20 to 22, wherein the manipulator for manipulating the sub-beams is configured to substantially collimate the sub-beam paths of the multi-beam.

[0186]

[0200] Clause 24: The charged particle system according to any one of clauses 20 to 23, wherein the charged particles are electrons.

[0187]

[0201] Clause 25: An electron beam inspection tool including the charged particle system according to any one of clauses 20 to 24.

[0188]

[0202] Clause 26: An electron beam lithography tool comprising a charged particle system according to any one of clauses 20 to 24.

[0189]

[0203] Clause 27: A multibeam manipulator device configured to act on a plurality of sub-beam paths of a charged particle multibeam to deflect the plurality of sub-beam paths, the sub-beams being arranged in an array in which the sub-beams are arranged in a series of lines, the multibeam manipulator device comprising a plurality of parallel planar electrode surface pairs;

[0204] the first pair of parallel planar electrode surfaces includes two opposing planar parallel electrode surfaces arranged on opposite sides along at least one of the lines of the sub-beams;

[0205] a second pair of planar parallel electrode surfaces including two opposing planar parallel electrode surfaces disposed on opposite sides along at least another one of the lines of the sub-beams;

[0206] A multi-beam manipulator device, wherein a first pair of parallel planar electrode surfaces and a second pair of parallel planar electrode surfaces extend across the multi-beam so as to intersect the array and are configured, in operation, to electrostatically interact with respective sub-beam paths in a line between the surface pairs.

[0190]

[0207] Clause 28: A multibeam manipulator configured to manipulate an array of sub-beam paths of a charged particle multibeam, the sub-beams being arranged in lines in the array, the lines being in at least two different line directions, the multibeam manipulator device comprising several deflector devices corresponding to a number of line directions in the array and arranged at different positions on the path of the multibeam, each deflector device comprising a plurality of parallel planar electrode surface pairs, the parallel planar electrode surfaces of each deflector device being aligned with different line directions, the plurality of parallel planar electrode surface pairs being aligned with two parallel planar electrode surface pairs arranged on opposite sides along at least one of the lines of the sub-beams. 1. A multi-beam manipulator comprising: a first parallel planar electrode surface pair comprising opposing planar-parallel electrode surfaces; and a second parallel planar electrode surface pair comprising two opposing planar-parallel electrode surfaces arranged on opposite sides along at least another one of the lines of sub-beams, where the at least another one of the lines of sub-beams is parallel to at least one of the lines of sub-beams, wherein the first parallel planar electrode surface pair and the second parallel planar electrode surface pair extend across the multi-beam to intersect the array and are configured, in operation, to electrostatically interact with each sub-beam path in the line between the surface pairs.

[0191]

[0208] Clause 29: A multibeam manipulator configured to manipulate an array of sub-beam paths of a charged particle multibeam, the sub-beams being arranged in lines in the array, the lines being in at least two different line directions, the multibeam manipulator device comprising a number of deflector devices corresponding to a number of line directions in the array and positioned along the multibeam paths, each deflector device comprising a plurality of opposing planar-parallel opposing electrode surfaces, the planar-parallel electrode surfaces of each deflector device being aligned in different line directions, the plurality of parallel planar electrode surface pairs comprising at least two opposing planar-parallel electrode surface pairs, wherein in the at least two opposing planar-parallel electrode surface pairs, each opposing planar-parallel surface pair is configured to cross across the multibeam array on either side of another at least one line of the sub-beam paths such that, in operation, each opposing planar-parallel electrode surface pair electrostatically interacts with all of the sub-beam paths in a respective at least one line between said surfaces.

[0192]

[0209] Clause 30: A multi-beam manipulator as described in clause 29, wherein the multi-beam manipulator is configured to deflect the sub-beams to a focal point.

[0193]

[0210] Clause 31: A method of deflecting paths of a plurality of sub-beams of a charged particle multi-beam, the sub-beams being arranged in an array in which the sub-beams are arranged in a plurality of lines, the method comprising: electrostatically interacting with an entire first line of sub-beams of the multi-beam such that a first deflection amount is applied to the paths of the sub-beams in a first direction; and electrostatically interacting with an entire second line of sub-beams of the multi-beam such that a second deflection amount is applied to the paths of the sub-beams in a second direction, the first direction being opposite to the second direction.

[0194]

[0211] Clause 32: A method of deflecting paths of a plurality of sub-beams of a charged particle multi-beam, the sub-beams being arranged in an array in which the sub-beams are arranged in a plurality of lines, the lines of the sub-beams being substantially parallel to each other across the array, the method comprising: electrostatically interacting with an entire first line of sub-beams of the multi-beam using a first parallel planar electrode surface pair of a set of electrodes comprising a plurality of parallel planar electrode surface pairs, such that a first deflection amount is applied to the path of the sub-beam in a first direction, the first parallel planar electrode surface pair being configured to be capable of deflecting all of the sub-beams in the first line of the sub-beams; and electrostatically interacting with an entire second line of sub-beams of the multi-beam using a second parallel planar electrode surface pair of the set of electrodes, such that a second deflection amount is applied to the path of the sub-beam in a second direction, the first direction being opposite to the second direction, the second parallel planar electrode surface pair being configured to be capable of deflecting all of the sub-beams in the second line of the sub-beams.

[0195]

[0212] Clause 33: A first pair of parallel planar electrode surfaces in the set includes a first planar electrode surface arranged along one side of a first line of sub-beams and a second planar electrode surface parallel to the first planar electrode surface and arranged along an opposite side of said first line of sub-beams.

[0196]

[0213] Clause 34: A second pair of parallel planar electrode surfaces in the set includes a first planar electrode surface arranged along one side of the second line of sub-beams and a second planar electrode surface parallel to the first planar electrode surface and arranged along an opposite side of the second line of sub-beams.

Claims

1. 1. A manipulator configured to manipulate a plurality of sub-beams of a charged particle sub-beam, the plurality of sub-beams being arranged in a plurality of lines in a two-dimensional array, the manipulator comprising: a first set of parallel electrodes arranged on either side of a first line of sub-beams in the two-dimensional array and configured for deflection of the first line of sub-beams; a second set of parallel electrodes disposed on either side of a second line of sub-beams in the two-dimensional array and downstream of the first set of parallel electrodes, the second set of parallel electrodes configured for deflection of the second line of sub-beams such that, when viewed along a charged particle optical axis, the first line of sub-beams are non-parallel and non-perpendicular to the second line of sub-beams; the first set of parallel electrodes includes two opposing planar parallel electrode surfaces disposed on either side of the first line of sub-beams; The manipulator further includes a third set of parallel electrodes arranged on either side of a third line of sub-beams in the two-dimensional array and positioned downstream of the second set of parallel electrodes, the third set of parallel electrodes being configured for deflection of the third line of sub-beams such that, when viewed along the charged particle optical axis, the first line of sub-beams are non-parallel and non-perpendicular to the second line of sub-beams and the third line of sub-beams.

2. The manipulator of claim 1 , wherein the second set of parallel electrodes includes two opposing planar parallel electrode surfaces disposed on either side of the second line of sub-beams.

3. The manipulator of claim 1 or 2, wherein the first line of sub-beams and the second line of sub-beams share one sub-beam of the plurality of sub-beams.

4. A manipulator configured to manipulate a plurality of sub-beams of a charged particle sub-beam, the plurality of sub-beams being arranged in a plurality of lines in a two-dimensional array, the manipulator comprising: a first set of parallel electrodes arranged on either side of a first line of sub-beams in the two-dimensional array and configured for deflection of the first line of sub-beams; a second set of parallel electrodes disposed on either side of a second line of sub-beams in the two-dimensional array and downstream of the first set of parallel electrodes, the second set of parallel electrodes configured for deflection of the second line of sub-beams such that, when viewed along a charged particle optical axis, the first line of sub-beams are non-parallel and non-perpendicular to the second line of sub-beams; the first set of parallel electrodes includes two opposing planar parallel electrode surfaces disposed on either side of the first line of sub-beams; A manipulator, wherein the first line of sub-beams and the second line of sub-beams are disposed at an angle of 60 degrees when viewed along a charged particle optical axis.

5. The manipulator of claim 1 , wherein the first line of sub-beams, the second line of sub-beams, and the third line of sub-beams share one sub-beam of the plurality of sub-beams.

6. A manipulator as described in any one of claims 1 to 5, wherein, when viewed along the charged particle optical axis, the positions of the multiple sub-beams in the two-dimensional array substantially correspond to vertices of a substantially square grid, a substantially diamond-shaped grid, and / or a substantially skewed or shifted square grid.

7. A manipulator as described in any one of claims 1 to 6, wherein, when viewed along the charged particle optical axis, the positions of the multiple sub-beams in the two-dimensional array substantially correspond to vertices of a substantially hexagonal grid and / or a substantially skewed or shifted hexagonal grid.

8. A manipulator configured to manipulate a plurality of sub-beams of a charged particle sub-beam, the plurality of sub-beams being arranged in a plurality of lines in a two-dimensional array, the manipulator comprising: a first set of parallel electrodes arranged on either side of a first line of sub-beams in the two-dimensional array and configured for deflection of the first line of sub-beams; a second set of parallel electrodes disposed on either side of a second line of sub-beams in the two-dimensional array and downstream of the first set of parallel electrodes, the second set of parallel electrodes configured for deflection of the second line of sub-beams such that, when viewed along a charged particle optical axis, the first line of sub-beams are non-parallel and non-perpendicular to the second line of sub-beams; the first set of parallel electrodes includes two opposing planar parallel electrode surfaces disposed on either side of the first line of sub-beams; the positions of the sub-beams in the two-dimensional array, when viewed along the charged particle optical axis, substantially correspond to vertices of a substantially hexagonal grid and / or a substantially skewed or shifted hexagonal grid; A manipulator, wherein when viewed along the charged particle optical axis, the positions of the plurality of sub-beams in the two-dimensional array follow a hexagonal close-packed arrangement.

9. A manipulator as described in any one of claims 1 to 8, wherein when viewed along the charged particle optical axis, the multiple sub-beams in the two-dimensional array are aligned in both a line parallel to a horizontal axis of the two-dimensional array and a line parallel to a vertical axis of the two-dimensional array.

10. A manipulator as claimed in any one of claims 1 to 9, wherein when viewed along the charged particle optical axis, the multiple sub-beams in the two-dimensional array are aligned in a line oblique to the horizontal and vertical axes of the two-dimensional array.

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