Multi-beam inspection equipment with single-beam mode

Abstract

A multi-beam inspection device supporting multiple operation modes is disclosed. A charged particle beam device for inspecting a sample supporting multiple operation modes includes a charged particle beam source configured to emit a charged particle beam along a main optical axis, a movable aperture plate movable between a first position and a second position, and a controller having a circuit system and configured to change the configuration of the device to switch between a first mode and a second mode. In a first mode, the movable aperture plate is located at a first position and is configured to allow a first charged particle beam wave originating from the charged particle beam to pass through. In a second mode, the movable aperture plate is located at a second position and is configured to allow a first charged particle beam wave and a second charged particle beam wave to pass through.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 62 / 826,731, filed on March 29, 2019, and U.S. Application No. 62 / 981,462, filed on February 25, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments provided herein relate generally to a multi-beam inspection apparatus, and more particularly to a multi-beam inspection apparatus supporting multiple operating modes. Background Art

[0004] When manufacturing semiconductor integrated circuit (IC) chips, pattern defects or foreign matter (residue) will inevitably appear on the wafer or mask during the manufacturing process, thereby reducing the yield. For example, for patterns with smaller critical feature sizes (which have been adopted to meet the increasingly advanced performance requirements of IC chips), unwelcome particles may cause trouble.

[0005] Pattern inspection tools with charged particle beams have been used to detect defects or unwelcome particles. These tools typically use a scanning electron microscope (SEM). In an SEM, a primary electron beam with relatively high energy is decelerated so that it falls on a sample with a relatively low landing energy and is focused to form a detection point thereon. Due to this focused detection point of the primary electrons, secondary electrons will be generated from the surface. Secondary electrons can include backscattered electrons, secondary electrons, or Auger electrons generated by the interaction of the primary electrons with the sample. By scanning the detection points on the sample surface and collecting the secondary electrons, the pattern inspection tool can acquire an image of the sample surface. Summary of the invention

[0006] The embodiments provided herein disclose a multi-beam inspection device, and more particularly disclose a multi-beam inspection device supporting multiple operation modes.

[0007] In some embodiments, a charged particle beam device for inspecting a sample supports multiple operating modes. The charged particle beam device includes a charged particle beam source configured to emit a charged particle beam along a main optical axis, a first aperture plate configured to form a plurality of charged particle beam waves from the charged particle beam, and a second aperture plate movable between a first position and a second position. The charged particle beam device also includes a controller having a circuit system and configured to change the configuration of the device to switch between a first mode and a second mode. When the device is operated in the first mode, the second aperture plate is located at the first position, and the first aperture plate and the second aperture plate are configured to allow a first charged particle beam wave in a plurality of charged particle beam waves to pass through. When the device is operated in the second mode, the second aperture plate is located at the second position, and the first aperture plate and the second aperture plate are configured to allow a first charged particle beam wave in a plurality of charged particles and a second charged particle beam wave to pass through.

[0008] In some embodiments, a method is disclosed that uses a charged particle beam device to examine a sample. The charged particle beam device may include a first aperture plate, the first aperture plate being configured to form a plurality of charged particle beam waves from a charged particle beam emitted by a charged particle beam source. The method includes moving a second aperture plate from a second position to a first position, wherein positioning the second aperture plate in the first position enables a single charged particle beam wave of the charged particle beam to pass through a combination of the first aperture plate and the second aperture plate, and positioning the second aperture plate in the second position enables a plurality of charged particle beam waves of the charged particle beam to pass through a combination of the first aperture plate and the second aperture plate.

[0009] In some embodiments, a charged particle beam device for inspecting a sample that supports multiple operating modes includes a charged particle beam source configured to emit a charged particle beam along a main optical axis, a movable aperture plate that can move between a first position and a second position, and a controller having a circuit system and configured to change the configuration of the device to switch between the first mode and the second mode. When the device is operated in the first mode, the movable aperture plate is located in the first position and is configured to allow a first charged particle beam wave in a plurality of charged particle beam waves derived from the charged particle beam to pass through. When the device is operated in the second mode, the movable aperture plate is located in the second position and is configured to allow a first charged particle beam wave and a second charged particle beam wave in a plurality of charged particle beam waves to pass through.

[0010] In some embodiments, the charged particle beam device further comprises a plurality of electron detection devices. In some embodiments, the first electron detection device is configured to detect secondary electrons emerging from the sample in the first mode, and the second electron detection device and / or the third electron detection device are configured to detect secondary electrons in the second mode.

[0011] Other advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which certain embodiments of the invention are set forth by way of illustration and example. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other aspects of the present disclosure will become more apparent through the description of exemplary embodiments with reference to the attached drawings.

[0013] Figure 1 is a schematic diagram illustrating an exemplary charged particle beam inspection system consistent with embodiments of the present disclosure.

[0014] Figure 2 is a diagram showing an embodiment consistent with the present disclosure Figure 1 Schematic diagram of an exemplary multi-beam apparatus that is part of an exemplary charged-particle beam inspection system.

[0015] Figure 3A and 3B is a schematic diagram of a multi-beam electron beam tool showing an exemplary configuration of a movable aperture plate consistent with embodiments of the present disclosure.

[0016] Figure 3C is consistent with the embodiments of the present disclosure Figure 3A and 3B Schematic diagram of an embodiment of a movable orifice plate.

[0017] Figure 4A and 4B is a schematic diagram of a multi-beam electron beam tool showing an exemplary configuration of a movable aperture plate consistent with embodiments of the present disclosure.

[0018] Figure 5A and 5B is a schematic diagram of a multi-beam electron beam tool showing an exemplary configuration of a movable aperture plate consistent with embodiments of the present disclosure.

[0019] Fig. 6A and 6B is a schematic diagram of a multi-beam electron beam tool showing an exemplary configuration of a movable aperture plate consistent with embodiments of the present disclosure.

[0020] Figure 6C is consistent with the embodiments of the present disclosure Fig. 6A and 6B Schematic diagram of an embodiment of a movable orifice plate.

[0021] Fig. 7A and 7B is a schematic diagram of a multi-beam electron beam tool showing an exemplary configuration of a secondary electron detection apparatus consistent with an embodiment of the present disclosure.

[0022] Fig. 8A and8B is a schematic diagram of a multi-beam electron beam tool showing an exemplary configuration of a secondary electron detection apparatus consistent with an embodiment of the present disclosure.

[0023] Fig. 9A , 9B 9C are schematic diagrams of a multi-beam electron beam tool showing an exemplary configuration of a secondary electron detection apparatus consistent with an embodiment of the present disclosure.

[0024] Fig. 10A and 10B is a schematic diagram of a multi-beam electron beam tool showing an exemplary configuration of a secondary electron detection apparatus consistent with an embodiment of the present disclosure.

[0025] Fig. 10C , 10D and 10E are consistent with the embodiments of the present disclosure Fig. 10B Schematic diagram of an embodiment of a secondary electron detection apparatus.

[0026] Fig.11 is a flow chart illustrating an exemplary method of inspecting a sample using a multi-beam electron beam tool consistent with embodiments of the present disclosure. DETAILED DESCRIPTION

[0027] Reference will now be made in detail to exemplary embodiments, examples of which are shown in the accompanying drawings. The following descriptions all refer to the accompanying drawings, and unless otherwise specified, the same reference numerals in different drawings represent the same or similar elements. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the present invention. Instead, they are merely examples of devices and methods consistent with aspects related to the present invention described in the appended claims.

[0028] Electronic devices are made up of circuits formed on a silicon wafer called a substrate. Many circuits can be formed together on the same silicon wafer and are called an integrated circuit or IC. The size of these circuits has been reduced significantly, allowing more circuits to fit on a substrate. For example, an IC chip in a smartphone can be as small as a thumb, but can include more than 2 billion transistors, each less than 1 / 1000 the size of a human hair.

[0029] Manufacturing these extremely small ICs is a complex, time-consuming and expensive process that typically involves hundreds of individual steps. An error in even one step can result in a defect in the finished IC, rendering it unusable. Therefore, one goal of the manufacturing process is to avoid such defects in order to maximize the number of functional ICs made in the process, i.e., to increase the overall yield of the process.

[0030] An integral part of improving yield is monitoring the chip manufacturing process to ensure that it produces a sufficient number of functional integrated circuits. One method for monitoring the process is to inspect the chip circuit structure at various stages of its formation. Inspection can be performed using a scanning electron microscope (SEM). The SEM can be used to image these extremely small structures, in effect taking a "photo" of the structure. The image can be used to determine whether the structure was formed correctly and whether it was formed in the right place. If the structure is defective, the process can be adjusted to make the defect less likely to occur again.

[0031] The SEM scans the surface of a sample with a focused beam of primary electrons. The primary electrons interact with the sample and generate secondary electrons. By scanning the sample with the focused beam and capturing the secondary electrons with a detector, the SEM creates an image of the scanned area of ​​the sample.

[0032] For high-throughput inspection, some inspection systems use multiple focused beams of electrons at once. Since multiple focused beams can scan different parts of the wafer at the same time, a multi-beam inspection system can inspect the wafer at a higher speed than a single-beam inspection system. However, due to crosstalk between adjacent electron beams, traditional multi-beam inspection systems have low detection accuracy and low resolution. Therefore, once defects on a sample are detected, traditional multi-beam inspection systems often require the sample to be transferred to a high-resolution single-beam inspection tool for a closer inspection of the detected defects. Even though some newer multi-beam inspection systems provide dual-mode support (e.g., multi-beam mode and single-beam mode), the maximum resolution during single-beam mode operation is still lower than the resolution that can be achieved using traditional single-beam inspection tools.

[0033] One of the main sources of limited resolution during single beam mode operation is the presence of off-axis electron beams that are not used when a multi-beam inspection system is operated in single beam mode. Since the electron source (e.g., electron gun) generates just as many electrons as would be generated in multi-beam mode, the adverse effects between electrons in single beam mode are just as high as in multi-beam mode, even though the off-axis electron beams are eventually filtered downstream. For example, Figure 2 The source conversion unit 220 in the Fig. 7A The beams 712 and 713 in the Figure 7B The detector 746 or hole (not shown) in the electron beam source is blocked from falling on the sample. One aspect of the present disclosure includes an adaptive control mechanism for electron beam generation that can eliminate unused off-axis electron beams near the electron beam source before they affect the on-axis electron beam when the tool is operated in single-beam mode, and thereby reduce single-beam degradation.

[0034] For clarity, the relative sizes of components in the drawings may be exaggerated. In the following description of the drawings, the same or similar reference numerals refer to the same or similar components or entities, and only the differences with respect to the various embodiments are described. As used herein, unless otherwise specifically stated, the term "or" encompasses all possible combinations unless not feasible. For example, if a component is stated to include A or B, then unless otherwise explicitly stated or not feasible, the component may include A, or B, or A and B. As a second example, if a component is stated to include A, B, or C, then unless otherwise explicitly stated or not feasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0035] Reference now Figure 1 , Figure 1 is a schematic diagram illustrating an exemplary charged particle beam inspection system 100 consistent with an embodiment of the present disclosure. Figure 1 As shown, the charged particle beam inspection system 100 includes a main chamber 10, a load lock chamber 20, an electron beam tool 40, and an equipment front end module (EFEM) 30. The electron beam tool 40 is located in the main chamber 10. Although the description and drawings are directed to electron beams, it should be understood that the embodiments are not intended to limit the present disclosure to specific charged particles.

[0036] The EFEM 30 includes a first load port 30a and a second load port 30b. The EFEM 30 may include additional load ports. For example, the first load port 30a and the second load port 30b may receive a front opening pod (FOUP) containing wafers (e.g., semiconductor wafers or wafers made of (multiple) other materials) or samples (wafers and samples are collectively referred to as "wafers" hereinafter) to be inspected. One or more robotic arms (not shown) in the EFEM 30 transfer the wafers to the load lock chamber 20.

[0037] The load lock chamber 20 may be connected to a load lock vacuum pump system (not shown) that removes gas molecules in the load lock chamber 20 to reach a first pressure below atmospheric pressure. After reaching the first pressure, one or more robotic arms (not shown) transfer the wafer from the load lock chamber 20 to the main chamber 10. The main chamber 10 is connected to a main chamber vacuum pump system (not shown) that removes gas molecules in the main chamber 10 to reach a second pressure below the first pressure. After reaching the second pressure, the wafer is subjected to inspection by an electron beam tool 40. In some embodiments, the electron beam tool 40 may include a single beam inspection tool. In other embodiments, the electron beam tool 40 may include a multi-beam inspection tool.

[0038] The controller 50 is electrically connected to the electron beam tool 40. The controller 50 may be a computer configured to perform various controls of the charged particle beam inspection system 100. The controller 50 may also include processing circuitry configured to perform various signal and image processing functions. Figure 1 Controller 50 is shown outside the structure including main chamber 10, load lock chamber 20 and EFEM 30, but it is understood that controller 50 may be part of the structure.

[0039] Although 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 in its broadest sense are not limited to chambers housing electron beam inspection tools. Rather, it should be understood that the aforementioned principles may also be applied to other tools operating at a second pressure.

[0040] Reference now Figure 2 , Figure 2 is a schematic diagram illustrating an exemplary electron beam tool 40 including a multi-beam inspection tool consistent with an embodiment of the present disclosure. Figure 1 A portion of an exemplary charged particle beam inspection system 100 of the present invention. A multi-beam electron beam tool 40 (also referred to herein as an apparatus) includes an electron source 201, a gun aperture plate 271, a beam wave pre-forming aperture array 272, a focusing lens 210, a source conversion unit 220, a primary projection system 230, a motorized stage 209, and a sample holder 207, the sample holder 207 being supported by the motorized stage 209 to hold a sample 208 to be inspected (e.g., a wafer or a photomask). The multi-beam electron beam tool 40 may also include a secondary projection system 250 and an electron detection device 240. The primary projection system 230 may include an objective lens 231. A beam splitter 233 and a deflection scanning unit 232 may be located inside the primary projection system 230. The electron detection device 240 may include a plurality of detection elements 241, 242, and 243.

[0041] The electron source 201, the gun aperture plate 271, the beam pre-forming aperture array 272, the condenser lens 210, the source conversion unit 220, the beam splitter 233, the deflection scanning unit 232 and the primary projection system 230 can be aligned with the main optical axis 204 of the device. The secondary projection system 250 and the electron detection device 240 can be aligned with the auxiliary optical axis 251 of the device.

[0042] The electron source 201 may include a cathode (not shown) and an extractor or an anode (not shown), wherein during operation, the electron source 201 is configured to emit primary electrons from the cathode and the primary electrons are extracted or accelerated by the extractor and / or the anode to form a primary electron beam 202, which forms a primary beam cross (virtual or real) 203. The primary electron beam 202 can be visualized as being emitted from the primary beam cross 203.

[0043] The source conversion unit 220 may include an image forming element array (not shown), an aberration compensator array (not shown), a beam limiting aperture array (not shown), and a pre-bending micro-deflector array (not shown). In some embodiments, the pre-bending micro-deflector array deflects multiple primary beam waves 211, 212, 213 of the primary electron beam 202 to normally enter the beam limiting aperture array, the image forming element array, and the aberration compensator array. In some embodiments, the condenser lens 210 is designed to focus the primary electron beam 202 into a parallel beam and make it vertically incident on the source conversion unit 220. The image forming element array may include a plurality of micro-deflectors or micro-lenses to affect the multiple primary beam waves 211, 212, 213 of the primary electron beam 202 and form a plurality of parallel images (virtual or real) of the primary beam cross 203, each of the primary beam waves 211, 212, and 213 having one parallel image. In some embodiments, the aberration compensator array may include a field curvature compensator array (not shown) and an astigmatism compensator array (not shown). The field curvature compensator array may include a plurality of micro lenses to compensate for the field curvature aberration of the primary beams 211, 212, and 213. The astigmatism compensator array may include a plurality of micro astigmatism filters to compensate for the astigmatism aberration of the primary beams 211, 212, and 213. The beam limiting aperture array may be configured to limit the diameters of the individual primary beams 211, 212, and 213. As an example, Figure 2 Three primary beams 211, 212 and 213 are shown, and it will be appreciated that the source conversion unit 220 may be configured to form any number of primary beams. The controller 50 may be connected to Figure 1 The various parts of the charged particle beam inspection system 100. In some embodiments, as explained in further detail below, the controller 50 can perform various image and signal processing functions. The controller 50 can also generate various control signals to manage the operation of the charged particle beam inspection system.

[0044] The condenser lens 210 is configured to focus the primary electron beam 202. The condenser lens 210 can also be configured to adjust the current of the primary beam waves 211, 212 and 213 downstream of the source conversion unit 220 by changing the focusing power of the condenser lens 210. Alternatively, the current can be changed by changing the radial size of the beam limiting holes within the beam limiting aperture array corresponding to the individual primary beam waves. The current can be changed by changing the radial size of the beam limiting holes and the focusing power of the condenser lens 210. The condenser lens 210 can be an adjustable condenser lens, and the adjustable condenser lens can be configured so that the position of its first principal plane is movable. The adjustable condenser lens can be configured to be magnetic, which can cause the off-axis beam waves 212 and 213 to illuminate the source conversion unit 220 at a rotation angle. The rotation angle varies with the focusing power or the position of the first principal plane of the adjustable condenser lens. Therefore, the condenser lens 210 may be an anti-rotation condenser lens, which may be configured to maintain a rotation angle when the focusing power of the condenser lens 210 changes. In some embodiments, the condenser lens 210 may be an adjustable anti-rotation condenser lens, wherein the rotation angle of the adjustable anti-rotation condenser lens does not change when the focusing power of the adjustable anti-rotation condenser lens and the position of its first principal plane change.

[0045] The objective lens 231 can be configured to focus the beams 211, 212, and 213 onto the sample 208 for inspection, and in the current embodiment, three detection points 221, 222, and 223 can be formed on the surface of the sample 208. The deflection scanning unit 232 is configured to deflect the primary beams 211, 212, and 213 in operation to scan the detection points 221, 222, and 223 on individual scanning areas in a portion of the surface of the sample 208. The aperture plate 271 is configured to block the peripheral electrons of the primary electron beam 202 in operation to reduce the Coulomb effect. The Coulomb effect may expand the size of each of the detection points 221, 222, and 223 of the primary beams 211, 212, and 213, and thus reduce the inspection resolution. In some embodiments, the beam pre-forming aperture array 272 further cuts the peripheral electrons of the primary electron beam 202 to reduce the Coulomb effect. The primary electron beam 202 may be shaped into three beams 211 , 212 , and 213 by the beam pre-forming aperture array 272 .

[0046] In response to the incidence of the primary beams 211, 212 and 213 or the detection points 221, 222 and 223 on the sample 208, electrons emerge from the sample 208 and generate three secondary electron beams 261, 262 and 263. Each of the secondary electron beams 261, 262 and 263 generally includes secondary electrons (electron energy ≤ 50 eV) and backscattered electrons (electron energy between 50 eV and the landing energy of the primary beams 211, 212 and 213).

[0047] The beam splitter 233 can be a Wien filter, which includes an electrostatic deflector that generates an electrostatic dipole field and a magnetic lens (not shown) that generates a magnetic dipole field. In operation, the beam splitter 233 can be configured to generate an electrostatic dipole field using the electrostatic deflector to apply an electrostatic force to individual electrons of the primary beam waves 211, 212, and 213. The beam splitter 233 can also be configured to generate a magnetic dipole field to apply a magnetic force to the electrons. The electrostatic force is equal to the magnetic force in magnitude but opposite in direction. The primary beam waves 211, 212, and 213 can therefore pass through the beam splitter 233 at least substantially in a straight line with a deflection angle that is at least substantially zero.

[0048] However, the secondary electron beams 261, 262 and 263 can be deflected toward the secondary projection system 250, which then focuses the secondary electron beams 261, 262 and 263 onto the detection elements 241, 242 and 243 of the electron detection device 240. The detection elements 241, 242 and 243 are arranged to detect the corresponding secondary electron beams 261, 262 and 263 and generate corresponding signals, which are sent to the controller 50 or a signal processing system (not shown), for example to construct an image of the corresponding scan area of ​​the sample 208.

[0049] In some embodiments, the detection elements 241, 242, and 243 detect the corresponding secondary electron beams 261, 262, and 263, respectively, and generate corresponding intensity signal outputs (not shown) to an image processing system (e.g., controller 50). In some embodiments, each detection element 241, 242, and 243 may include one or more pixels. The intensity signal output of the detection element may be the sum of the signals generated by all pixels within the detection element.

[0050] In some embodiments, the controller 50 may include an image processing system including an image acquisition device (not shown) and a storage device (not shown). The image acquisition device may include one or more processors. For example, the image acquisition device may include a computer, a server, a mainframe, a terminal, a personal computer, any kind of mobile computing device, or the like, or a combination thereof. The image acquisition device may be communicatively coupled to the electronic detection device 240 of the device through a medium such as an electrical conductor, a fiber optic cable, a portable storage medium, IR, Bluetooth, the Internet, a wireless network, radio, or a combination thereof. In some embodiments, the image acquisition device may receive a signal from the electronic detection device 240 and may construct an image. The image acquisition device may thus acquire an image of the sample 208. The image acquisition device may also perform various post-processing functions, such as generating contours, superimposing indicators on the acquired image, and the like. The image acquisition device may be configured to perform brightness and contrast adjustments, etc. on the acquired image. In some embodiments, the storage device may be a storage medium such as a hard disk, a flash drive, a cloud storage, a random access memory (RAM), other types of computer-readable memory, and the like. The storage device may be coupled to the image acquisition device and may be used to save the scanned raw image data as a raw image and save a post-processed image.

[0051] In some embodiments, the image acquirer can acquire one or more images of the sample based on the imaging signal received from the electronic detection device 240. The imaging signal can correspond to a scanning operation for performing charged particle imaging. The acquired image can be a single image including multiple imaging areas. The single image can be stored in a storage device. The single image can be an original image, and the original image can be divided into multiple areas. Each of the areas can include an imaging area containing features of the sample 208. The acquired image can include multiple images of a single imaging area of ​​the sample 208 sampled multiple times in a time series. Multiple images can be stored in a storage device. In some embodiments, the controller 50 can be configured to perform an image processing step on multiple images of the same position of the sample 208.

[0052] In some embodiments, the controller 50 may include a measurement circuit system (e.g., an analog-to-digital converter) to obtain the distribution of the detected secondary electrons. The electron distribution data collected during the detection time window combined with the corresponding scan path data of each of the primary beam waves 211, 212, and 213 incident on the wafer surface can be used to reconstruct an image of the inspected wafer structure. The reconstructed image can be used to reveal various features of the internal or external structure of the sample 208, and thus can be used to reveal any defects that may exist in the wafer.

[0053] In some embodiments, the controller 50 may control the motorized stage 209 to move the sample 208 during the inspection of the sample 208. In some embodiments, the controller 50 may enable the motorized stage 209 to continuously move the sample 208 in one direction at a constant speed. In other embodiments, the controller 50 may enable the motorized stage 209 to change the movement speed of the sample 208 over time according to the steps of the scanning process. In some embodiments, the controller 50 may adjust the configuration of the primary projection system 230 or the secondary projection system 250 based on the images of the secondary electron beams 261, 262, and 263.

[0054] Although Figure 2 The electron beam tool 40 is shown using three primary electron beams, but it should be understood that the electron beam tool 40 may use two or more primary electron beams. The present disclosure does not limit the number of primary electron beams used in the apparatus.

[0055] In some embodiments, a multi-beam device may provide a mechanism for supporting single beam mode operation. For example, a multi-beam device may control a deflector array (e.g., Figure 2 The deflector array in the source conversion unit 220) adjusts multiple primary beams (for example, Figure 2 The deflection angle of the beams 211, 212 and 213 in the sample is such that only one of the multiple primary beams will reach the sample (e.g., Figure 2 The surface of the sample 208). An example of a multi-beam device that supports single mode operation can be found in U.S. Patent No. 9,691,586, which is incorporated herein by reference in its entirety. In order to obtain higher resolution images of the sample using the single beam mode, it may be necessary to further reduce the Coulomb effect. In some embodiments, if the multi-beam device in single beam mode can have a resolution as good as that of a traditional single beam device, the multi-beam device can first perform a multi-beam inspection, which generally provides a higher yield than a traditional single beam device, and then use the single beam mode to perform a high-resolution inspection of the defect of interest. This can eliminate the need for a traditional single beam inspection tool for the second step. In addition, this can also improve the overall yield of the inspection process because the high-throughput inspection step and the high-resolution inspection step can be performed within one tool, thereby shortening the time to transfer the sample from the first tool to the second tool.

[0056] Reference now Figure 3A and 3B , Figure 3A and 3B 373 is a schematic diagram of a multi-beam electron beam tool 300 showing an exemplary configuration of a movable aperture plate 373 consistent with an embodiment of the present disclosure. The multi-beam electron beam tool 300 may be a multi-beam device (e.g., Figure 2 part of a multi-beam device).

[0057] As previously mentioned Figure 2 As described, the multi-beam electron beam tool 300 may include an electron source 301, a gun hole plate 371, a beam wave pre-forming aperture array 372, and a focusing lens 310. The electron source 301 is configured to emit primary electrons and form a primary electron beam 302. The gun hole plate 371 is configured to block peripheral electrons of the primary electron beam 302 to reduce the Coulomb effect, which may reduce the inspection resolution. In some embodiments, the beam wave pre-forming aperture array 372 further cuts the peripheral electrons of the primary electron beam 302 to reduce the Coulomb effect. The primary electron beam 302 can be trimmed into three primary electron beam waves 311, 312 and 313 (or any other number of beam waves) after passing through the beam wave pre-forming aperture array 372. The electron source 301, the gun hole plate 371, the beam wave pre-forming aperture array 372, and the focusing lens 310 can be aligned with the main optical axis 304 of the multi-beam electron beam tool 300.

[0058] In some embodiments, the multi-beam electron beam tool 300 may further include a movable aperture plate 373 , which may be used to support multiple operating modes of the electron beam tool 300 , such as a single beam mode and a multi-beam mode.

[0059] In single beam mode, Figure 3A As shown, the movable aperture plate 373 can be moved to a first position between the beam pre-forming aperture array 372 and the condenser lens 310. When the movable aperture plate 373 is placed in the first position, the hole of the movable aperture plate 373 can be aligned with the main optical axis 304. The movable aperture plate 373 can be configured to block off-axis beams (e.g., beams 312 and 313) during the single beam mode and only allow the on-axis beam (e.g., beam 311) to pass through. In some embodiments, the movable aperture plate 373 may include a plurality of holes (e.g., having various sizes) of holes. Figure 3C ). In such an embodiment, different sized apertures may be selected during single beam mode depending on the desired current level of the beam. For example, a larger aperture may be used when a high current electron beam is desired.

[0060] In multi-beam mode, Figure 3B As shown, the movable aperture plate 373 can be moved to a second position, where the movable aperture plate 373 is far enough from the path of the primary electron beam waves 311, 312 and 313 so that the primary electron beam waves 311, 312 and 313 will pass through.

[0061] Reference now Figure 3C , Figure 3C is consistent with the embodiments of the present disclosure Figure 3A and 3BSchematic diagram of an embodiment of a movable aperture plate 373. In some embodiments, the movable aperture plate 373 may include one or more apertures. In some embodiments, the movable aperture plate 373 may include multiple apertures of different sizes to change the current of the primary electron beam wave when the electron beam tool is operated in a single beam mode. Figure 3C A rectangular movable orifice plate is shown, but it should be understood that the movable orifice plate 373 can be a different shape. For example, the movable orifice plate 373 can be a circular plate with a plurality of holes. The present disclosure does not limit the shape of the movable orifice plate 373.

[0062] Reference now Figure 4A and 4B , Figure 4A and 4B is a schematic diagram of a multi-beam electron beam tool 400A and 400B showing an exemplary configuration of a movable aperture plate consistent with an embodiment of the present disclosure. The multi-beam electron beam tool 400A and 400B can be a multi-beam device (e.g., Figure 2 part of a multi-beam device).

[0063] Similar to Figure 3A and 3B In the configuration shown, the multi-beam electron beam tools 400A and 400B may include an electron source 401, a gun aperture plate 471, a beam pre-forming aperture array 472, a focusing lens 410, and movable aperture plates (e.g., 473a and 473b). However, Figure 4A and 4B Embodiments of multi-beam electron beam tools with movable aperture plates in different configurations are shown. Figure 4A and 4B It is shown that the movable aperture plate can be moved to different positions for the single beam mode relative to other structures aligned with the main optical axis 404, such as the gun aperture plate 471, the beam pre-forming aperture array 472 and the condenser lens 410.

[0064] For example, Figure 4A The movable aperture plate 473a can be located above the beam preforming aperture array 472 and below the gun aperture plate 471 to achieve single beam mode operation. In such an embodiment, the movable aperture plate 473a can trim the off-axis portion of the primary electron beam 402 to generate a single beam, such as the electron beam 411, after the beam preforming aperture array 472.

[0065] on the other hand, Figure 4B The movable aperture plate 473b may be located below the condenser lens 410 to enable single beam mode operation by blocking all off-axis beam waves (eg, beam waves 412 and 413) and allowing only the on-axis beam wave (eg, beam wave 411) to pass through during the single beam mode.

[0066] Reference now Figure 5A and 5B , Figure 5A and 5B 5 is a schematic diagram of a multi-beam electron beam tool 500 showing an exemplary configuration of a movable aperture plate 573 consistent with an embodiment of the present disclosure. The multi-beam electron beam tool 500 may be a multi-beam device (e.g., Figure 2 part of a multi-beam device).

[0067] Similar to the previously described embodiments, the multi-beam electron beam tool 500 may include an electron source 501 , a gun aperture plate 571 , a beam pre-forming aperture array 572 , a condenser lens 510 , and a movable aperture plate 573 . Figure 5A and 5B Additional embodiments of multi-beam electron beam tools with movable aperture plates of different configurations are shown. In some embodiments, the focusing lens 510 can include two or more lenses that operate in combination to change the path of the primary electron beam wave. The two or more lenses can be electrostatic lenses, magnetic lenses, or a combination of the two. For example, Figure 5A An embodiment of a focusing lens 510 including two magnetic lenses 510a and 510b is shown. In such an embodiment, Figure 5B As shown, the movable aperture plate 573 can be moved to a position between the two magnetic lenses 510a and 510b to block the off-axis electron beam waves 512, 513, thereby achieving single beam mode operation. It should be understood that the movable aperture plate 573 can be of various shapes. For example, the movable aperture plate 573 can be as follows: Figure 3C The movable aperture plate can be a circular plate with a plurality of holes. In such an embodiment, the circular aperture plate can be rotated so that holes of different sizes are aligned with the optical axis to allow electrons to pass through. The rotating circular aperture plate can be suitable for use in a small space, such as within the focusing lens 510.

[0068] Reference now Fig. 6A , 6B and 6C, Fig. 6A , 6B 6C are schematic diagrams of a multi-beam electron beam tool 600 showing an exemplary configuration of a movable aperture plate 673 consistent with an embodiment of the present disclosure. The multi-beam electron beam tool 600 may be a multi-beam device (e.g., Figure 2 part of a multi-beam device).

[0069] Similar to the previously described embodiments, the multi-beam electron beam tool 600 may include an electron source 601, a beam pre-forming aperture array 672, a focusing lens 610, and a movable aperture plate 673. Fig. 6A and 6B As shown, the gun hole plate can be replaced with a movable hole plate 673 including two or more holes thereon, wherein the first hole (e.g., Figure 6C The hole 673a) is used for the single beam mode, while the second hole (e.g., Figure 6C Hole 673b) is used for multi-beam mode.

[0070] For example, in single beam mode, Fig. 6A As shown, the movable aperture plate 673 can be moved to a first position above the beam pre-forming aperture array 672. When the movable aperture plate 673 is placed in the first position, the first hole (e.g., Figure 6C The aperture 673a) is aligned with the main optical axis 604. The first aperture may include a small opening configured to trim an off-axis portion of the primary electron beam 602, thereby generating a single beam wave, such as electron beam wave 611, after the beam wave pre-forming aperture array 672.

[0071] In multi-beam mode, Figure 6B As shown, the movable orifice plate 673 can be moved to the second position. When the movable orifice plate 673 is placed in the second position, the second hole (e.g., Figure 6C The second aperture 673b is aligned with the main optical axis 604. The second aperture may include a larger opening that enables a larger portion of the primary electron beam 602 to pass through, thereby generating multiple beam waves: an on-axis beam wave (e.g., beam wave 611) and an off-axis beam wave (e.g., beam waves 612 and 613). In such an embodiment, by allowing a sufficiently large portion of the primary electron beam 602 to pass through to generate multiple beam waves, while blocking peripheral electrons of the primary electron beam 602 to reduce Coulomb effects, the second aperture can be effectively used as a gun aperture array in a multi-beam mode (e.g., Figure 3B The gun hole plate 371).

[0072] Although Figure 6C A movable orifice plate of rectangular shape is shown, and it is understood that the movable orifice plate 673 can be a different shape. For example, the movable orifice plate 673 can be a circular plate with a plurality of holes. The present disclosure does not limit the shape of the movable orifice plate 373.

[0073] Reference now Fig. 7A and 7B , Fig. 7A and 7B is a schematic diagram of a multi-beam electron beam tool 700 showing an exemplary configuration of secondary electron detection devices 740 and 746 consistent with embodiments of the present disclosure. Fig. 7A The multi-beam mode of operation of the multi-beam electron beam tool 700 is shown. Figure 7B A single beam operating mode of the multi-beam electron beam tool 700 is shown.

[0074] In some embodiments, the multi-beam electron beam tool 700 may include an objective lens 731, which is configured to focus beams 711, 712, and 713 onto a sample 708 for inspection and may form three detection points 721, 722, and 723 on the surface of the sample 708. The multi-beam electron beam tool 700 may include a multi-beam detection device 740 and a single-beam detection device 746, which are configured to detect secondary electrons during a multi-beam mode and a single-beam mode, respectively. The multi-beam detection device 740 may be aligned with the secondary optical axis 751. The single-beam detection device 746 may be aligned with the primary optical axis 704.

[0075] The multi-beam electron beam tool 700 may further include a beam splitter 733 configured to deflect the secondary electrons in different directions based on the operating mode of the multi-beam electron beam tool 700. Fig. 7A As shown, in the multi-beam mode, the beam splitter 733 can be configured to deflect the secondary electron beams 761, 762 and 763 along the auxiliary optical axis 751 toward the multi-beam detection device 740. On the other hand, in the single beam mode, as shown in FIG. Figure 7B As shown, the beam splitter 733 can be disabled so that the secondary electron beam 761 can be detected by the single beam detection device 746, which can be specially designed to enhance the detection of secondary electrons generated by a single beam (e.g., primary beam 711).

[0076] Reference now Fig. 8A and 8B , Fig. 8A and 8B is a schematic diagram of a multi-beam electron beam tool 800 showing an exemplary configuration of secondary electron detection devices 840 and 846 consistent with embodiments of the present disclosure. Fig. 8A The multi-beam mode of operation of the multi-beam electron beam tool 800 is shown. Figure 8B A single beam operating mode of the multi-beam electron beam tool 800 is shown.

[0077] The multi-beam electron beam tool 800 can be used as previously described. Fig. 7A and 7B During the multi-beam mode, the beam splitter 833 can be configured to deflect the secondary electron beams 861, 862, and 863 along the secondary optical axis 851 toward the multi-beam detection device 840. During the single-beam mode, the beam splitter 833 can be configured to be disabled so that the secondary electron beam 861 can be detected by the single-beam detection device 846, which can be specifically designed to detect a single beam of secondary electrons.

[0078] However, the multi-beam electron beam tool 800 and Fig. 7A and 7BA significant difference of the multi-beam electron beam tool 700 is that in some embodiments, the single beam detection device 846 may be movable. For example, during multi-beam mode, such as Fig. 8A As shown, the single beam detection device 846 can be moved away from the main optical axis 804 to generate a space for multiple beams (e.g., beams 811, 812, and 813) to pass through. During the single beam mode, as shown in FIG. Figure 8B As shown, the single beam detection device 846 can be moved to a position aligned with the primary optical axis 804 to detect the secondary electron beam 861. Because the single beam detection device 846 moves away during the multi-beam mode, the single beam detection device 846 can be more convenient than a fixed design (e.g., Fig. 7A The single beam detection device 746) is larger to enable the ability to provide higher resolution during single beam mode inspection.

[0079] Reference now Fig. 9A , 9B and 9C, Fig. 9A , 9B 9C are schematic diagrams of a multi-beam electron beam tool 900 showing an exemplary configuration of secondary electron detection devices 940 and 946 consistent with embodiments of the present disclosure. The multi-beam electron beam tool 900 may be a multi-beam device (e.g., Figure 2 part of a multi-beam device). Fig. 9A The multi-beam mode of operation of the multi-beam electron beam tool 900 is shown. Fig. 9B and 9C A single beam operating mode of the multi-beam electron beam tool 900 is shown.

[0080] The multi-beam electron beam tool 900 can be used as previously described. Fig. 7A and 7B During the multi-beam mode, the beam splitter 933 may be configured to deflect the secondary electron beams 961 , 962 and 963 along the first secondary optical axis 951 towards the multi-beam detection device 940 .

[0081] However, the multi-beam electron beam tool 900 is Fig. 7A and 7B A significant difference of the multi-beam electron beam tool 700 is that in some embodiments, the single beam detection device 946 may not be aligned with the primary optical axis 904. In such embodiments, during the single beam mode, the beam splitter 933 may be configured to deflect the secondary electron beam 961 toward the single beam detection device 946, which may be aligned with the second secondary optical axis 952, such as Fig. 9B In some embodiments, the first secondary optical axis 951 and the second secondary optical axis 952 are symmetrical with respect to the primary optical axis 904. However, it should be understood that the optical axes 951 and 952 may be asymmetrical.

[0082] like Fig. 9CAs shown, in some embodiments, the multi-beam electron beam tool 900 may also include an energy filter 947 in front of the single beam detection device 946. The energy filter 947 may also be aligned with the second auxiliary optical axis 952. The energy filter 947 can be configured to enhance the detection of backscattered electrons, which typically have higher energy than normal secondary electrons. In some embodiments, the energy filter 947 can selectively allow electrons with specific energy levels to pass through. For example, the energy filter 947 can be tuned to allow only high-energy electrons (e.g., backscattered electrons) to pass through so that more backscattered electrons can reach the single beam detection device 946 than normal secondary electrons.

[0083] Reference now Fig. 10A and 10B , Fig. 10A and 10B is a schematic diagram of a multi-beam electron beam tool 1000 showing an exemplary configuration of secondary electron detection devices 1046 and 1080 consistent with embodiments of the present disclosure.

[0084] The multi-beam electron beam tool 1000 can be used in the same manner as previously described with respect to Fig. 7A 8A / 8B and 8A / 8B. When the multi-beam electron beam tool 1000 is operated in the multi-beam mode, the beam splitter 1033 can be configured to deflect the secondary electron beam 1061 toward the multi-beam detection device 1040. When the multi-beam electron beam tool 1000 is operated in the single beam mode, such as Fig. 10A and 10B As shown, the beam splitter 1033 can be configured to be disabled so that the secondary electron beam 1061 can be detected by the single beam detection device 1046, which can be specially designed to detect a single beam of secondary electrons. Fig. 7A and 7B In some embodiments, similar to the single beam detection device 746, the single beam detection device 1046 is immovable. Fig. 8A and 8B The single beam detection device 846 and the single beam detection device 1046 are movable.

[0085] In response to the primary beam 1011 being incident on the sample 1008, a secondary electron beam may be emitted from the sample 1008. The secondary electron beam may include secondary electrons (e.g., 1061) and backscattered electrons (e.g., 1081, 1082, and 1083), as shown in FIG. Fig. 10A and 10BAs shown. Secondary electrons 1061 have lower emission energy and are therefore easily focused by objective lens 1031 to be detected by single beam detection device 1046. Backscatter has higher electron emission energy and is therefore difficult to be focused by objective lens 1031. Therefore, only backscattered electrons (such as 1081) with a smaller emission angle can be detected by single beam detection device 1046.

[0086] However, if Fig. 10A As shown, backscattered electrons with larger emission angles (e.g., 1082 and 1083) cannot be sufficiently focused during single beam mode and may not be detected by single beam detection device 1046. In some embodiments, capturing backscattered electrons with larger emission angles (e.g., 1082 and 1083) may be useful for defect inspection because those backscattered electrons may include topographic and material information about sample 1008.

[0087] like Fig. 10B As shown, in some embodiments, an additional single beam detection device 1080 can be used to capture backscattered electrons with a larger emission angle. The additional single beam detection device 1080 can be placed between the objective lens 1031 and the sample 1008.

[0088] In some embodiments, similar to Fig. 7A and 7B In the embodiment of the present invention, the additional single beam detection device 1080 may be non-movable. In such an embodiment, the additional single beam detection device 1080 may be designed to have a sufficiently large inner hole diameter 1095 to avoid blocking the primary electron beam (e.g., Fig. 8A beam waves 811, 812, 813) and secondary electron beams (for example, secondary electron beams 861, 862, 863).

[0089] In some embodiments, similar to Fig. 8A and 8B For example, during the multi-beam mode, the additional single beam detection device 1080 can be moved away from the main optical axis 1004 to create space for multiple beams to pass through. Fig. 10B As shown, the additional single beam detection device 1080 can be moved to a position aligned with the main optical axis 1004 to detect backscattered electrons with larger emission angles, such as backscattered electrons 1082 and 1083.

[0090] Because the additional single beam detection device 1080 is moved away during the multi-beam mode, the additional single beam detection device 1080 can be optimized to collect backscattered electrons when operating in the single beam mode. For example, the inner aperture diameter 1095 of the additional single beam detection device 1080 can be smaller than a fixed design, thereby producing a larger detection area. This optimization can provide the ability to capture more backscattered electrons, which can improve the imaging resolution and inspection throughput of the sample 1008 during single beam mode inspection.

[0091] In some embodiments, capturing secondary electrons and backscattered electrons according to the emission angle may be more helpful for defect inspection because this information is related to the pattern orientation on the sample surface or inside the sample. Therefore, the single beam detection device 1046 and the additional single beam detection device 1080 may include multiple detection areas or be segmented, such as Fig. 10C , 10D and 10E.

[0092] Reference now Fig. 10C , 10D and 10E, Fig. 10C , 10D 10E shows an embodiment consistent with the present disclosure Fig. 10B Schematic diagram of an exemplary embodiment of an additional single beam detection device 1080. In some embodiments, the additional single beam detection device 1080 may include a single annular detection area 1080a, such as Fig. 10C shown.

[0093] From samples (e.g. Fig. 10B The backscattered electrons emitted by the sample 1008) can provide different information depending on the shape and orientation of the features implemented in the sample. Therefore, in some embodiments, the additional secondary electron detection device 1080 can include multiple segments of the detection area, so that more specific information related to the features on the sample can be obtained.

[0094] Fig. 10D An example of an additional single beam detection device 1080 is shown. In some embodiments, the additional single beam detection device 1080 may include detection segments 1080b, 1080c, 1080d, and 1080e positioned along the rotation direction 1096. This enables detection of backscattered electrons in terms of their emission azimuth (emission angle in the circumferential direction) and facilitates defect inspection of certain types of samples.

[0095] Fig. 10EAnother example of an additional single beam detection device 1080 is shown. In some embodiments, the additional single beam detection device 1080 may include detection segments 1080f and 1080g positioned along a radial direction 1097. This enables detection of backscattered electrons in terms of their emission radial angle (emission angle relative to the surface normal) and facilitates defect inspection of certain types of samples.

[0096] In some embodiments, Fig. 10A and 10B The single beam detection device 1046 may include a single annular detection area (e.g., Fig. 10C A single annular detection area 1080a as shown) or multiple detection segments (e.g., Fig. 10D The detection segments 1080b-1080e are arranged in a rotational manner or Fig. 10E Detection sections 1080f-1080g) are arranged radially in the middle.

[0097] Reference now Fig.11 , Fig.11 is a diagram showing the use of a multi-beam electron beam tool (e.g., Figure 3A Flow chart of an exemplary method for inspecting a sample using a multi-beam electron beam tool 300 of FIG. 1 . In some embodiments, the multi-beam electron beam tool may include an electron source (e.g., Figure 3A The electron source 301), the gun hole plate (for example, Figure 3A The aperture plate 371 of the gun), the beam pre-forming aperture array (for example, the beam pre-forming aperture array 372) and the focusing lens (for example, Figure 3A The electron source is configured to emit primary electrons and form a primary electron beam (eg, Figure 3A The primary electron beam 302 is formed by the aperture plate. The aperture plate is configured to block peripheral electrons of the primary electron beam to reduce the Coulomb effect, which may reduce the detection resolution. In some embodiments, the beam preforming aperture array further cuts the peripheral electrons of the primary electron beam to reduce the Coulomb effect. After passing through the beam preforming aperture array, the primary electron beam can be trimmed into a plurality of primary electron beams (e.g., Figure 3A The electron beam waves 311, 312 and 313 in FIG.

[0098] In some embodiments, the multi-beam electron beam tool may also include a movable aperture plate (e.g., Figure 3A and 3B The movable aperture plate 373 of the electron beam tool can be used to support multiple operating modes of the electron beam tool, such as a single beam mode and a multi-beam mode. In some embodiments, the multi-beam electron beam tool can also include a controller having a circuit system and configured to change the configuration of the multi-beam electron beam tool to switch between the multi-beam mode and the single beam mode.

[0099] In step 1110, a sample is loaded into a multi-beam electron beam tool for inspection. In step 1120, when the multi-beam electron beam tool is placed in a multi-beam mode inspection, a controller enables a movable aperture plate to move from a first position to a second position to perform a multi-beam inspection of the sample. In some embodiments, in the multi-beam mode, the movable aperture plate can be in the second position, and the movable aperture plate is far enough away from the path of multiple primary electron beam waves when in the second position so that those primary beam waves will pass through.

[0100] In step 1130, when the multi-beam electron beam tool is placed in the single beam mode, the controller enables the movable aperture plate to move from the second position to the first position to perform a single beam high resolution inspection of the sample. In some embodiments, when the movable aperture plate is placed in the first position, the aperture of the movable aperture plate can be aligned with the primary optical axis. The movable aperture plate can be configured to block off-axis primary electron beam waves (e.g., Figure 3A beams 312 and 313) and only allow on-axis beams (e.g., Figure 3A The beam wave 311) passes through.

[0101] The embodiments may be further described using the following terms:

[0102] 1. A charged particle beam apparatus for examining a sample supporting multiple modes of operation, comprising:

[0103] a charged particle beam source configured to emit a charged particle beam along a main optical axis;

[0104] a first aperture plate configured to form a plurality of charged particle beam waves from the charged particle beam;

[0105] a second orifice plate movable between a first position and a second position; and

[0106] A controller having circuitry and configured to change a configuration of a device to switch between a first mode and a second mode, wherein:

[0107] In the first mode:

[0108] The second orifice plate is located at a first position, and

[0109] The first aperture plate and the second aperture plate are configured to allow a first charged particle beam wave of the plurality of charged particle beam waves to pass therethrough, and

[0110] In the second mode:

[0111] The second orifice plate is located at a second position, and

[0112] The first aperture plate and the second aperture plate are configured to allow a first charged particle beam wave and a second charged particle beam wave of the plurality of charged particle beam waves to pass therethrough.

[0113] 2. The apparatus of clause 1, wherein the first mode is a single beam mode and the second mode is a multi-beam mode.

[0114] 3. Apparatus according to any of clauses 1 to 2, wherein the first charged particle beam wave is an on-axis beam wave relative to a main optical axis and the second charged particle beam wave is an off-axis beam wave relative to the main optical axis.

[0115] 4. Apparatus according to any of clauses 1 to 3, wherein the second aperture plate is configured to block the second charged particle beam wave when the apparatus is operated in the first mode.

[0116] 5. Apparatus according to any of clauses 1 to 4, wherein the first aperture plate is located between the charged particle beam source and the second aperture plate when the apparatus is operated in the first mode.

[0117] 6. The apparatus according to any one of clauses 1 to 5, further comprising:

[0118] A condenser lens is configured to change the paths of the plurality of charged particle beam waves to form a plurality of images of the charged particle beam source on an image plane.

[0119] 7. Apparatus according to clause 6, wherein the second aperture plate is located between the first aperture plate and the condenser lens when the apparatus is operated in the first mode.

[0120] 8. The apparatus according to clause 6, wherein when the apparatus is operated in the first mode, the condenser lens is located between the first aperture plate and the second aperture plate.

[0121] 9. Apparatus according to clause 6, wherein the focusing lens comprises a first deflector and a second deflector, and wherein the second aperture plate is located between the first deflector and the second deflector when the apparatus is operated in the first mode.

[0122] 10. Apparatus according to any of clauses 1 to 4, wherein the second aperture plate is located between the charged particle beam source and the first aperture plate when the apparatus is operated in the first mode.

[0123] 11. The apparatus according to any one of clauses 1 to 10, further comprising:

[0124] a beam splitter configured to deflect secondary electrons generated from the sample; and

[0125] The first electron detection device is configured to detect secondary electrons when the device is operated in the first mode or the second mode.

[0126] 12. The apparatus of clause 11, wherein the controller comprises circuitry for:

[0127] In the first mode or the second mode, the beam splitter is controlled to deflect the secondary electrons towards the first electron detection device, wherein the first electron detection device is aligned with the first secondary optical axis.

[0128] 13. The apparatus according to any one of clauses 1 to 10, further comprising:

[0129] a beam splitter configured to deflect secondary electrons generated from the sample;

[0130] a first electron detection arrangement configured to detect secondary electrons when the apparatus is operated in the second mode; and

[0131] A second electron detection device is configured to detect secondary electrons when the device is operated in the first mode.

[0132] 14. The apparatus of clause 13, wherein the controller comprises circuitry for:

[0133] in a second mode, controlling the beam splitter to deflect the secondary electrons towards a first electron detection device, wherein the first electron detection device is aligned with the first secondary optical axis, and

[0134] In the first mode, the beam splitter is disabled to allow secondary electrons to travel towards the second electron detection device.

[0135] 15. Apparatus according to clause 14, wherein the second electronic detection means is aligned with the main optical axis.

[0136] 16. Apparatus according to clause 14, wherein the second electronic detection device is movable between a third position and a fourth position, wherein:

[0137] If the apparatus is configured in the first mode, the second electron detection device is located in a third position to detect secondary electrons, the second electron detection device being aligned with the main optical axis when in the third position, and

[0138] If the device is configured to be in the second mode, the second electronic detection device is located in a fourth position, and the second electronic detection device is away from the main optical axis in the fourth position.

[0139] 17. The apparatus of clause 13, wherein the controller comprises circuitry for:

[0140] During a second mode, controlling the beam splitter to deflect the secondary electrons towards a first electron detection device, wherein the first electron detection device is aligned with the first secondary optical axis, and

[0141] During the first mode, the beam splitter is controlled to deflect the secondary electrons towards a second electron detection device, wherein the second electron detection device is aligned with the second secondary optical axis.

[0142] 18. The device according to clause 17, wherein the first secondary optical axis and the second secondary optical axis are symmetrical about the primary optical axis.

[0143] 19. Apparatus according to any of clauses 17 and 18, wherein the second electron detection means comprises an electron detector for detecting secondary electrons and an energy filter in front of the electron detector for enhancing the detection of backscattered electrons.

[0144] 20. The apparatus according to any one of clauses 1 to 10, further comprising:

[0145] a beam splitter configured to deflect secondary electrons generated from the sample;

[0146] a first electron detection arrangement configured to detect secondary electrons when the apparatus is operated in the second mode;

[0147] a second electron detection arrangement configured to detect a first portion of the secondary electrons when the apparatus is operated in a first mode; and

[0148] A third electron detection device is configured to detect a second portion of the secondary electrons when the device is operated in the first mode.

[0149] 21. The apparatus according to clause 20, wherein the second portion of secondary electrons comprises electrons having a higher energy than the electrons of the first portion of secondary electrons.

[0150] 22. The apparatus of clause 20, wherein the second portion of secondary electrons comprises electrons having an emission angle greater than that of the electrons of the first portion of secondary electrons.

[0151] 23. Apparatus according to any of clauses 20 to 22, wherein the second portion of the secondary electrons comprises backscattered electrons emitted from the sample.

[0152] 24. Apparatus according to any of clauses 20 to 23, wherein the second electronic detection means and the third electronic detection means are aligned with the main optical axis.

[0153] 25. Apparatus according to any one of clauses 20 to 23, wherein:

[0154] a third electron detection device aligned with the principal optical axis to detect a second portion of the secondary electrons, and

[0155] The second electronic detection device is movable between a third position and a fourth position, wherein:

[0156] If the apparatus is configured in the first mode, the second electron detection device is located in a third position to detect the first portion of the secondary electrons, the second electron detection device being aligned with the main optical axis when in the third position, and

[0157] If the device is configured to be in the second mode, the second electronic detection device is located in a fourth position, and the second electronic detection device is away from the main optical axis in the fourth position.

[0158] 26. Apparatus according to any one of clauses 20 to 23, wherein:

[0159] a second electron detection device aligned with the principal optical axis to detect a first portion of the secondary electrons, and

[0160] The third electronic detection device is movable between a fifth position and a sixth position, wherein:

[0161] If the apparatus is configured in the first mode, the third electron detection device is located in a fifth position to detect the second portion of the secondary electrons, the third electron detection device being aligned with the main optical axis when in the fifth position, and

[0162] If the device is configured to be in the second mode, the third electronic detection device is located in a sixth position, and the third electronic detection device is away from the main optical axis in the sixth position.

[0163] 27. Apparatus according to any one of clauses 20 to 23, wherein:

[0164] The second electronic detection device is movable between a third position and a fourth position, and

[0165] The third electronic detection device is movable between a fifth position and a sixth position, wherein:

[0166] If the apparatus is configured to be in the first mode, the second electron detection device is in a third position to detect a first portion of the secondary electrons, the second electron detection device being aligned with the main optical axis when in the third position, and the third electron detection device is in a fifth position to detect a second portion of the secondary electrons, the third electron detection device being aligned with the main optical axis when in the fifth position, and

[0167] If the device is configured in the second mode, the second electronic detection device is located in the fourth position and the third electronic detection device is located in the sixth position, wherein the second electronic detection device and the third electronic detection device are away from the main optical axis.

[0168] 28. Apparatus according to any of clauses 20 to 27, wherein the second electronic detection device comprises a plurality of detection segments, the third electronic detection device comprises a plurality of detection segments, or the second electronic detection device and the third electronic detection device comprise a plurality of detection segments.

[0169] 29. The apparatus according to any one of clauses 1 to 28, wherein the second orifice plate comprises a first orifice, wherein:

[0170] If the apparatus is configured in a first mode, the second aperture plate is in a first position such that the first aperture is aligned with the principal optical axis, and

[0171] If the device is configured in the second mode, the second aperture plate is in a second position such that the first aperture is away from the primary optical axis.

[0172] 30. The apparatus according to clause 29, wherein the second orifice plate further comprises a second orifice that is larger than the first orifice, wherein:

[0173] If the apparatus is configured in the third mode, the second aperture is located in the fifth position such that the second aperture is aligned with the primary optical axis to block the second charged particle beam wave and produce a higher current detection point on the sample compared to the first aperture.

[0174] 31. The apparatus according to any one of clauses 1 to 28, wherein the second aperture plate comprises a first aperture and a second aperture, wherein:

[0175] If the apparatus is configured in a first mode, the second aperture plate is in a first position such that the first aperture is aligned with the principal optical axis, and

[0176] If the device is configured in the second mode, the second aperture plate is in the second position such that the second aperture is aligned with the primary optical axis.

[0177] 32. The device according to clause 31, wherein the second hole is larger than the first hole.

[0178] 33. Apparatus according to any one of clauses 1 to 32, wherein the second orifice plate is a circular plate.

[0179] 34. Apparatus according to clause 33, wherein the second aperture plate rotates about the principal optical axis.

[0180] 35. A method, the method comprising: examining a sample using a charged particle beam apparatus, the charged particle beam apparatus comprising a first aperture plate, the first aperture plate being configured to form a plurality of charged particle beam waves from a charged particle beam emitted by a charged particle beam source, the method comprising:

[0181] The second orifice plate is moved from the second position to the first position, wherein:

[0182] positioning the second aperture plate in the first position such that a single charged particle beam wave of the charged particle beam can pass through the combination of the first aperture plate and the second aperture plate, and

[0183] Positioning the second aperture plate in the second position enables a plurality of charged particle beam waves of the charged particle beam to pass through the combination of the first aperture plate and the second aperture plate.

[0184] 36. The method according to clause 35, further comprising:

[0185] The second orifice plate is moved from the first position to the second position.

[0186] 37. The method according to any of clauses 35 and 36, wherein the single charged particle beam wave is an on-axis charged particle beam wave relative to a main optical axis.

[0187] 38. A method according to any of clauses 35 to 37, wherein the second aperture plate is configured to block off-axis charged particle beam waves when in the first position.

[0188] 39. A charged particle beam apparatus for examining a sample supporting multiple modes of operation, comprising:

[0189] a charged particle beam source configured to emit a charged particle beam along a main optical axis;

[0190] a movable orifice plate movable between a first position and a second position; and

[0191] A controller having circuitry and configured to change a configuration of a device to switch between a first mode and a second mode, wherein:

[0192] In the first mode:

[0193] The movable aperture plate is located in a first position and is configured to allow a first charged particle beam wave of a plurality of charged particle beam waves derived from the charged particle beam to pass therethrough, and

[0194] In the second mode:

[0195] The movable aperture plate is located at a second position and is configured to allow a first charged particle beam wave and a second charged particle beam wave of the plurality of charged particle beam waves to pass therethrough.

[0196] 40. The device of clause 39, wherein the first mode is a single beam mode and the second mode is a multi-beam mode.

[0197] 41. Apparatus according to any of clauses 39 to 40, wherein the first charged particle beam wave is an on-axis beam wave relative to a principal optical axis and the second charged particle beam wave is an off-axis beam wave relative to the principal optical axis.

[0198] 42. Apparatus according to any of clauses 39 to 41, wherein the movable aperture plate is configured to block the second charged particle beam wave when the apparatus is operated in the first mode.

[0199] 43. The apparatus according to any of clauses 39 to 42, further comprising a beam pre-forming aperture plate, wherein the beam pre-forming aperture plate is located between the charged particle beam source and the movable aperture plate when the apparatus is operated in the first mode.

[0200] 44. Apparatus according to any one of clauses 39 to 43, further comprising:

[0201] A condenser lens is configured to change the paths of the plurality of charged particle beam waves to form a plurality of images of the charged particle beam source on an image plane.

[0202] 45. Apparatus according to clause 44, wherein when the apparatus is operated in the first mode, the movable aperture plate is located between the beam pre-forming aperture plate and the condenser lens.

[0203] 46. ​​Apparatus according to clause 44, wherein when the apparatus is operated in the first mode, the focusing lens is located between the beam pre-forming aperture plate and the movable aperture plate.

[0204] 47. Apparatus according to clause 44, wherein the focusing lens comprises a first deflector and a second deflector, and wherein when the apparatus is operated in the first mode, the movable aperture plate is located between the first deflector and the second deflector.

[0205] 48. The apparatus according to any of clauses 39 to 42, further comprising a beam pre-forming aperture plate, wherein when the apparatus is operated in the first mode, the movable aperture plate is located between the charged particle beam source and the beam pre-forming aperture plate.

[0206] 49. The apparatus according to any one of clauses 39 to 48, further comprising:

[0207] a beam splitter configured to deflect secondary electrons generated from the sample; and

[0208] The first electron detection device is configured to detect secondary electrons when the device is operated in the first mode or the second mode.

[0209] 50. The apparatus of clause 49, wherein the controller comprises circuitry for:

[0210] In the first mode or the second mode, the beam splitter is controlled to deflect the secondary electrons towards the first electron detection device, wherein the first electron detection device is aligned with the first secondary optical axis.

[0211] 51. Apparatus according to any one of clauses 39 to 48, further comprising:

[0212] a beam splitter configured to deflect secondary electrons generated from the sample;

[0213] a first electron detection arrangement configured to detect secondary electrons when the apparatus is operated in the second mode; and

[0214] A second electron detection device is configured to detect secondary electrons when the device is operated in the first mode.

[0215] 52. The apparatus of clause 51, wherein the controller comprises circuitry for:

[0216] in a second mode, controlling the beam splitter to deflect the secondary electrons towards a first electron detection device, wherein the first electron detection device is aligned with the first secondary optical axis, and

[0217] In the first mode, the beam splitter is disabled to allow secondary electrons to travel towards the second electron detection device.

[0218] 53. Apparatus according to clause 52, wherein the second electronic detection means is aligned with the main optical axis.

[0219] 54. Apparatus according to clause 52, wherein the second electronic detection device is movable between a third position and a fourth position, wherein:

[0220] If the apparatus is configured in the first mode, the second electron detection device is located in a third position to detect secondary electrons, the second electron detection device being aligned with the main optical axis when in the third position, and

[0221] If the device is configured to be in the second mode, the second electronic detection device is located in a fourth position, and the second electronic detection device is away from the main optical axis in the fourth position.

[0222] 55. The apparatus of clause 51, wherein the controller comprises circuitry for:

[0223] During a second mode, controlling the beam splitter to deflect the secondary electrons towards a first electron detection device, wherein the first electron detection device is aligned with the first secondary optical axis, and

[0224] During the first mode, the beam splitter is controlled to deflect the secondary electrons towards a second electron detection device, wherein the second electron detection device is aligned with the second secondary optical axis.

[0225] 56. The device according to clause 55, wherein the first secondary optical axis and the second secondary optical axis are symmetrical about the primary optical axis.

[0226] 57. Apparatus according to any of clauses 55 and 56, wherein the second electron detection means comprises an electron detector for detecting secondary electrons and an energy filter in front of the electron detector for enhancing the detection of backscattered electrons.

[0227] 58. Apparatus according to any one of clauses 39 to 48, further comprising:

[0228] a beam splitter configured to deflect secondary electrons generated from the sample;

[0229] a first electron detection arrangement configured to detect secondary electrons when the apparatus is operated in the second mode;

[0230] a second electron detection arrangement configured to detect a first portion of the secondary electrons when the apparatus is operated in a first mode; and

[0231] A third electron detection arrangement is configured to detect a second portion of the secondary electrons when the device is operated in the first mode.

[0232] 59. The apparatus of clause 58, wherein the second portion of secondary electrons comprises electrons having a higher energy than electrons of the first portion of secondary electrons.

[0233] 60. The apparatus of clause 58, wherein the second portion of secondary electrons comprises electrons having an emission angle greater than that of the electrons of the first portion of secondary electrons.

[0234] 61. An apparatus according to any of clauses 58 to 60, wherein the second portion of the secondary electrons comprises backscattered electrons emitted from the sample.

[0235] 62. Apparatus according to any of clauses 58 to 61, wherein the second electronic detection means and the third electronic detection means are aligned with the main optical axis.

[0236] 63. Apparatus according to any one of clauses 58 to 62, wherein:

[0237] a third electron detection device aligned with the principal optical axis to detect a second portion of the secondary electrons, and

[0238] The second electronic detection device is movable between a third position and a fourth position, wherein:

[0239] If the apparatus is configured in the first mode, the second electron detection device is located in a third position to detect the first portion of the secondary electrons, the second electron detection device being aligned with the main optical axis when in the third position, and

[0240] If the device is configured to be in the second mode, the second electronic detection device is located in a fourth position, and the second electronic detection device is away from the main optical axis in the fourth position.

[0241] 64. Apparatus according to any one of clauses 58 to 62, wherein:

[0242] a second electron detection device aligned with the principal optical axis to detect a first portion of the secondary electrons, and

[0243] The third electronic detection device is movable between a fifth position and a sixth position, wherein:

[0244] If the apparatus is configured in the first mode, the third electron detection device is located in a fifth position to detect the second portion of the secondary electrons, the third electron detection device being aligned with the main optical axis when in the fifth position, and

[0245] If the device is configured to be in the second mode, the third electronic detection device is located in a sixth position, and the third electronic detection device is away from the main optical axis in the sixth position.

[0246] 65. Apparatus according to any one of clauses 58 to 62, wherein:

[0247] The second electronic detection device is movable between a third position and a fourth position, and

[0248] The third electronic detection device is movable between a fifth position and a sixth position, wherein:

[0249] If the apparatus is configured to be in the first mode, the second electron detection device is in a third position to detect a first portion of the secondary electrons, the second electron detection device being aligned with the main optical axis when in the third position, and the third electron detection device is in a fifth position to detect a second portion of the secondary electrons, the third electron detection device being aligned with the main optical axis when in the fifth position, and

[0250] If the device is configured in the second mode, the second electronic detection device is located in the fourth position and the third electronic detection device is located in the sixth position, wherein the second electronic detection device and the third electronic detection device are away from the main optical axis.

[0251] 66. The device according to any of clauses 58 to 65, wherein the second electronic detection device comprises a plurality of detection segments, the third electronic detection device comprises a plurality of detection segments, or the second electronic detection device and the third electronic detection device comprise a plurality of detection segments.

[0252] 67. Apparatus according to any one of clauses 39 to 66, wherein the movable aperture plate comprises a first aperture, wherein:

[0253] If the apparatus is configured in a first mode, the movable aperture plate is in a first position such that the first aperture is aligned with the principal optical axis, and

[0254] If the device is configured in the second mode, the movable aperture plate is in the second position such that the first aperture is away from the primary optical axis.

[0255] 68. The apparatus of clause 67, wherein the movable aperture plate further comprises a second aperture that is larger than the first aperture, wherein:

[0256] If the apparatus is configured in the third mode, the second aperture is located in the fifth position such that the second aperture is aligned with the primary optical axis to block the second charged particle beam wave and produce a higher current detection point on the sample compared to the first aperture.

[0257] 69. The apparatus of any one of clauses 39 to 66, wherein the movable aperture plate comprises a first aperture and a second aperture, wherein:

[0258] If the apparatus is configured in a first mode, the movable aperture plate is in a first position such that the first aperture is aligned with the principal optical axis, and

[0259] If the device is configured in the second mode, the movable aperture plate is in the second position such that the second aperture is aligned with the primary optical axis.

[0260] 70. The device according to clause 69, wherein the second hole is larger than the first hole.

[0261] 71. Apparatus according to any one of clauses 39 to 70, wherein the movable orifice plate is a circular plate.

[0262] 72. Apparatus according to clause 71, wherein the movable aperture plate rotates about the principal optical axis.

[0263] A non-transitory computer readable medium may be provided that stores a controller (eg, Figure 1 The processor of the controller 50 of the embodiment of the present invention performs the operation mode switching between the multi-beam mode and the single-beam mode (for example, controlling Fig. 8A and 8B Common forms of non-transitory media include, for example, floppy disks, flexible disks, hard disks, solid-state drives, magnetic tapes or any other magnetic data storage medium, compact disk read-only memory (CD-ROM), any other optical data storage medium, any physical medium with a pattern of holes, random access memory (RAM), programmable read-only memory (PROM) and erasable programmable read-only memory (EPROM), FLASH-EPROM or any other flash memory, non-volatile random access memory (NVRAM), cache, registers, any other memory chip or cartridge, and network versions thereof.

[0264] It should be understood that the embodiments of the present disclosure are not limited to the exact constructions described above and shown in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof. The present disclosure has been described in conjunction with various embodiments, and other embodiments of the present invention will be clear to those skilled in the art in view of the description and practice of the invention disclosed herein. The description and embodiments are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0265] The above description is intended to be illustrative, and not restrictive. It will therefore be apparent to one skilled in the art that modifications described may be made without departing from the scope of the claims set forth below.

Claims

1. A charged particle beam apparatus for examining a sample supporting multiple modes of operation, comprising: a charged particle beam source configured to emit a charged particle beam along a main optical axis; a first aperture plate configured to form a plurality of charged particle beam waves from the charged particle beam; a second orifice plate movable between a first position and a second position; as well as A controller having circuitry and configured to change a configuration of the charged particle beam device to switch between a first mode and a second mode, wherein: In the first mode: The second aperture plate is located at the first position, and the first aperture plate and the second aperture plate are configured to allow a first charged particle beam wave of the plurality of charged particle beam waves to pass therethrough, and In the second mode: the second orifice plate is located at the second position, and The first aperture plate and the second aperture plate are configured to allow the first charged particle beam wave and the second charged particle beam wave of the plurality of charged particle beam waves to pass therethrough, Wherein the second aperture plate comprises an aperture, when the apparatus is configured in the second mode, the second aperture plate is positioned at the second position such that the aperture is positioned apart from the primary optical axis. 2 . The apparatus of claim 1 , wherein the first mode is a single beam mode and the second mode is a multi-beam mode. 3 . The apparatus of claim 1 , wherein the first charged particle beam wave is an on-axis beam wave relative to the main optical axis, and the second charged particle beam wave is an off-axis beam wave relative to the main optical axis. 4 . The device of claim 1 , wherein the second aperture plate is configured to block the second charged particle beam wave when the device is operated in the first mode.

5. The apparatus of claim 1, wherein the first aperture plate is located between the charged particle beam source and the second aperture plate when the apparatus is operated in the first mode.

6. The device according to claim 1, further comprising: A condenser lens is configured to change the paths of the plurality of charged particle beam waves to form a plurality of images of the charged particle beam source on an image plane.

7. The apparatus of claim 6, wherein the second aperture plate is located between the first aperture plate and the condenser lens when the apparatus is operated in the first mode.

8. The apparatus of claim 6, wherein the condenser lens is located between the first aperture plate and the second aperture plate when the apparatus operates in the first mode.

9. The apparatus of claim 6, wherein the focusing lens comprises a first deflector and a second deflector, and wherein the second aperture plate is located between the first deflector and the second deflector when the apparatus is operated in the first mode.

10. The apparatus of claim 1, wherein the second aperture plate is located between the charged particle beam source and the first aperture plate when the apparatus is operated in the first mode.

11. The device according to claim 1, further comprising: a beam splitter configured to deflect secondary electrons generated from the sample; as well as A first electron detection device is configured to detect the secondary electrons when the device is operated in the first mode or the second mode.

12. The apparatus of claim 11, wherein the controller comprises circuitry for: In the first mode or the second mode, the beam splitter is controlled to deflect the secondary electrons towards the first electron detection device, wherein the first electron detection device is aligned with a first secondary optical axis.

13. The apparatus according to claim 1, further comprising: a beam splitter configured to deflect secondary electrons generated from the sample; a first electron detection device configured to detect said secondary electrons when said apparatus is operated in said second mode; as well as A second electron detection device is configured to detect the secondary electrons when the device is operated in the first mode.

14. The apparatus of claim 13, wherein the controller comprises circuitry for: in the second mode, controlling the beam splitter to deflect the secondary electrons towards the first electron detection device, wherein the first electron detection device is aligned with a first secondary optical axis, and In the first mode, the beam splitter is disabled to allow the secondary electrons to travel towards the second electron detection device.

15. A method for examining a sample using a charged particle beam device, the charged particle beam device comprising a first aperture plate configured to form a plurality of charged particle beam waves from a charged particle beam emitted along a primary optical axis by a charged particle beam source, the charged particle beam device further comprising a controller having circuitry and configured to change a configuration of the charged particle beam device to switch between a first mode and a second mode, the method comprising: in the first mode, positioning a second aperture plate included in the charged particle beam device at a first position so that a first charged particle beam wave among the plurality of charged particle beam waves can pass through a combination of the first aperture plate and the second aperture plate, and in the second mode, positioning the second aperture plate at a second position so that the first and second charged particle beam waves of the plurality of charged particle beam waves can pass through a combination of the first and second aperture plates, Wherein the second aperture plate comprises an aperture, when the apparatus is configured in the second mode, the second aperture plate is positioned at the second position such that the aperture is positioned apart from the primary optical axis.

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