Scanning patterns for scientific instruments

Abstract

To solve the problems with the prior art.SOLUTION: The invention provides systems and methods for adjusting scanning patterns in scientific instruments based on electromagnetic interference. One exemplary charged particle instrument includes a chamber supporting a sample, a column coupled to the chamber, a pump configured to establish a vacuum within the chamber, a sensing device configured to detect a measurement of a frequency of electromagnetic interference generated via the pump, and a controller including an electronic processor and a memory. The column includes a charged particle source configured to generate a charged particle beam traveling through the column into the chamber. The charged particle beam is generated according to a scanning pattern. The controller is configured to receive, from the sensing device, a signal indicative of the frequency of the electromagnetic interference and adjust the scanning pattern based on the frequency of the electromagnetic interference.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure generally relates to systems and methods for adjusting a scanning pattern in a scientific instrument based on electromagnetic interference, such as electromagnetic interference generated within a charged particle system.

Summary of the Invention

[0002] Scanning scientific instruments, such as charged particle systems, include components that generate electromagnetic interference, such as a molecular pump. Other sensitive components involved in measuring a sample, such as a column and detection electronics, may be located near the electromagnetic interference. For example, the electromagnetic interference may change the scanning pattern while scanning a sample. Typically, shielding may be provided to block the electromagnetic interference. Alternatively, the sensitive components may be located away from the electromagnetic interference. However, as the size of the instrument decreases, it is becoming increasingly difficult to reduce the effects of the electromagnetic interference.

[0003] Embodiments described herein implement an antenna near an electromagnetic interference generating component of a scientific instrument. The antenna is tuned to an approximate frequency of the electromagnetic interference. The measured frequency of the electromagnetic interference is provided to a controller configured to adjust a scanning pattern of the scientific instrument based on the interference. For example, scanning can be avoided during peaks of the electromagnetic interference.

[0004] In one aspect, a charged particle instrument includes a chamber that supports a sample, a column coupled to the chamber, and a pump configured to establish a vacuum within the chamber. The column includes a charged particle source configured to generate a charged particle beam that travels into the chamber through the column. The charged particle beam is generated according to a scanning pattern. The charged particle instrument also includes a sensing device configured to detect a measured value of a frequency of electromagnetic interference generated via the pump, and a controller that includes an electronic processor and a memory. The controller is configured to receive, from the sensing device, a signal indicative of the frequency of the electromagnetic interference and to adjust the scanning pattern based on the frequency of the electromagnetic interference.

[0005] In another aspect, a charged particle device includes a chamber that supports a sample and a column coupled to the chamber. The column includes a charged particle source configured to generate a charged particle beam that travels into the chamber through the column. The charged particle beam is generated according to a scanning pattern. The charged particle device also includes an antenna configured to detect the frequency of electromagnetic interference generated by the charged particle device, and a controller including an electronic processor and a memory. The controller is configured to receive, from the antenna, a signal indicative of the frequency of the electromagnetic interference and to align the start of each scan line forming the scanning pattern with a zero crossing of the electromagnetic interference.

[0006] In another aspect, a method of adjusting a scanning pattern in a charged particle device includes receiving, from an antenna and using an electronic processor, a signal indicative of the frequency of electromagnetic interference. The electromagnetic interference is generated by a pump configured to establish a vacuum in a chamber that supports a sample. The method includes using the electronic processor to adjust the scanning pattern of the charged particle beam based on the frequency of the electromagnetic interference. The charged particle beam is generated by a charged particle source of a column. The column is coupled to the chamber and the charged particle beam travels through the column into the chamber.

[0007] There is no specific requirement that a system, method, or technique related to scanning a scientific instrument include all of the details characterized herein in order to obtain any benefit according to the present disclosure. Accordingly, the specific examples characterized herein are illustrative applications of the techniques described and alternative forms are possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The features and advantages of the present technology will become more apparent from the following detailed description of its exemplary embodiments in conjunction with the accompanying drawings.

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Figure 5B

[0009] Although the present technology has room for various modified forms and alternative forms, specific embodiments are shown in the drawings as examples and described in detail herein. However, it should be understood that the present invention is not limited to the specific forms disclosed. Rather, the present invention includes all modified forms, equivalents, and alternative forms that fall within the spirit and scope of the present invention as defined by the appended claims.

Embodiments for Carrying Out the Invention

[0010] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will prevail. Exemplary methods and systems are described below, but methods and systems similar or equivalent to those described herein can be used in the practice or testing of the present disclosure. The systems, methods, and examples disclosed herein are merely illustrative and not intended to be limiting.

[0011] As used herein, the terms "comprising," "including," "having," "has," "can," "containing," and variations thereof are intended to be open transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0012] The modifier "about" when used in connection with a quantity includes the recited value and has the meaning determined by the context (e.g., including at least the degree of error associated with the measurement of a particular quantity). The modifier "about" should also be considered to disclose a range defined by the absolute values of the two endpoints. For example, the expression "about 2 to about 4" also discloses the range "2 to 4." The term "about" can refer to plus or minus 10% of the indicated number. For example, "about 10%" can indicate a range of 9% to 11%, and "about 1" can mean 0.9 to 1.1. Other meanings of "about" can be apparent from the context, such as rounding, for example, "about 1" can also mean 0.5 to 1.4.

[0013] As used herein, the term "or" means an inclusive "or" rather than an exclusive "or." That is, unless otherwise specified or apparent from the context, "X employs A or B" means any natural inclusive substitution. That is, in the cases of "X employs A," "X employs B," or "X employs both A and B," "X employs A or B" satisfies the conditions of all the foregoing examples. Further, the articles "a" and "an" used in this specification and the accompanying drawings should generally be construed to mean "one or more" unless otherwise specified to indicate the singular form or otherwise apparent from the context.

[0014] Regarding the enumeration of numerical ranges in this specification, each number intervening therebetween is explicitly contemplated with the same degree of precision. For example, for the range of 6 to 9, in addition to 6 and 9, the numbers 7 and 8 are contemplated, and for the range of 6.0 to 7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are explicitly contemplated.

[0015] Hereinafter, the present disclosure will be described with reference to the drawings, in which like reference numerals are used throughout to refer to like elements. In the following description, for illustrative purposes, many specific details are set forth in order to facilitate an understanding of the present disclosure. However, it will be apparent that the systems and methods of the present disclosure may be practiced without one or more of these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to simplify the description of the systems and methods of the present invention.

[0016] FIG. 1 is a block diagram illustrating a scientific instrument 100 according to some embodiments. The scientific instrument 100 includes a scanning transmission electron microscope (STEM) column 102 coupled to a vacuum chamber 108. The vacuum chamber 108 houses a movable sample holder 110 and can be evacuated using one or more vacuum pumps 190. In an exemplary embodiment, the sample holder 110 is movable independently parallel to the XY coordinate plane and parallel to the Z coordinate axis, and the corresponding coordinate system is indicated by the XYZ coordinate triad shown in FIG. 1. A sample S to be investigated using the scientific instrument 100 is mounted on the sample holder 110 as shown in FIG. 1.

[0017] In the illustrated embodiment, the STEM column 102 comprises an electron source 112 and two or more electron beam lenses. In FIG. 1, for illustrative purposes, only two of them (the objective lens 106 and the condenser lens 116, collectively referred to as electron beam lenses) are schematically shown. In some embodiments, a (different) number of such lenses may be used within the STEM column 102. In some embodiments, the objective lens 106 may be an ultra-high-resolution (UHR) lens.

[0018] During operation, the electron source 112 generates an electron beam 114 that propagates generally along the longitudinal axis 115 of the STEM column 102. The electron beam lenses 106 and 116 operate to generate electric and magnetic fields that affect the electron trajectories within the electron beam 114. The control signals 152, 156 generated by the electron controller 150 are used to change the intensity and / or spatial configuration of these fields and impart desired characteristics to the electron beam 114. In general, the electron beam lenses 106 and 116, the control signals 152 and 156, and other related components of the scientific instrument 100 can be used to perform various operations and support various functions such as beam focusing, aberration correction, aperture clipping, and filtering. In some embodiments, the STEM column 102 further comprises a deflection unit 118 that can steer the electron beam 114 in response to a control signal 154 applied by the electron controller 150. Such beam steering can be used to move the focused portion of the electron beam 114 along a desired path across the sample S, for example, to perform a raster scan or a vector scan of the sample S. The path of the electron beam 114 may hereinafter be referred to as a scan pattern.

[0019] Scientific instrument 100 also includes detectors 160, 170, 180 located within vacuum chamber 108, relatively close to sample S. During operation, detectors 160, 170, and 180 generate a stream of measurements 162, 172, and 182 received by electronic controller 150. The specific type of detectors 160, 170, 180 depends on the embodiment of scientific instrument 100 and can typically be selected from a variety of detector types suitable for detecting different types of emissions and / or radiation from sample S generated in response to electron beam 114. Exemplary types of emissions / radiation that can be generated in this manner include, but are not limited to, X-rays, infrared rays, visible light, ultraviolet rays, backscattered electrons, secondary electrons, Auger electrons, elastically scattered electrons, unscattered (e.g., zero energy loss) electrons, and inelastically scattered electrons. In various embodiments, different numbers of such detectors can be used within scientific instrument 10. In some embodiments, detectors 160, 170, 180 are selected from the group consisting of a high-angle annular dark-field detector, a medium-angle annular dark-field detector, an annular bright-field detector, a segmented annular detector, a differential phase contrast detector, and a two-dimensional (e.g., pixelated) diffraction pattern detector. Other detectors capable of detecting various ones of the types of emissions / radiation mentioned above can also be used in various additional embodiments.

[0020] Additionally, the scientific instrument 100 includes an electron source 112 that generates an electron beam 114, but the embodiments described herein may be implemented with other types of charged particle sources and charged particle instruments that include charged particle beams. For example, an ion source may generate an ion beam for scanning a sample S. An exemplary pump 190 illustrated is a turbomolecular pump that includes a turbine-shaped rotor driven by an electric motor to rotate at high speed. This electric motor includes a stationary magnet and a rotating magnet that generate an electromagnetic field that changes over time at the same frequency as the rotation frequency of the motor, and this electromagnetic field affects the path of the electron beam 114 and / or the detectors 160, 170, 180. Further, in some implementations of the turbomolecular pump, magnetic bearings are employed instead of (or in addition to) other types of bearings that can cause additional electromagnetic interference.

[0021] In some implementations, the illustrated pump 190 may be replaced with another type of pump. For example, the pump 190 may be a turbo pump, a rotary mechanical pump, an oil diffusion pump, etc.

[0022] Antenna 194 (e.g., a sensing device) is coupled to the outer surface of pump 190. In some examples, as shown in FIG. 2, antenna 194 is mounted, bolted, or otherwise fixed to the outer surface of pump 190 via fastener 200. In some examples, antenna 194 is mounted to a printed circuit board (PCB) 202, and PCB 202 is mounted to the outer surface of pump 190. Also, in some cases, antenna 194 can be mounted near pump 190 without being mounted to pump 190. For example, antenna 194 can be mounted to a support structure of device 100 at a location within the outer surface of device 100 near pump 190. Antenna 194 senses electromagnetic interference generated by pump 190 and transmits a signal representative of the sensed electromagnetic interference to electronic controller 150. In some examples, antenna 194 transmits a signal representative of amplified sensed electromagnetic interference to electronic controller 150. The electromagnetic interference generated by pump 190 can have a frequency of 1000 Hz to 2000 Hz (e.g., 1500 Hz).

[0023] In FIG. 1, scientific instrument 10 is illustrated as a STEM instrument, but scientific instrument 10 can be or can include one or more different types of optical microscopes and / or charged particle microscopes, such as, but not limited to, a scanning electron microscope (SEM), STEM, transmission electron microscope (TEM), charged particle microscope (CPM), cryogenic-compatible microscope, focused ion beam (FIB) microscope, dual beam microscope system, or combinations thereof.

[0024] FIG. 3 illustrates a block diagram of the electronic controller 150. The electronic controller 150 includes, among other things, an electronic processor 300, a memory 302, and an input / output (I / O) interface 304. However, it should be understood that the electronic controller 150 may have additional or fewer components. The electronic controller 150 is suitable for use and configuration, and for example, may include multiple electronic processors, multiple I / O interfaces, multiple data storage devices, or combinations thereof. In some implementations, some or all of the components included in the electronic controller 150 may be attached to one or more motherboards and housed in a housing (e.g., including plastic, metal, and / or other materials). In some implementations, some of these components can be fabricated on a single system-on-chip, or SoC (e.g., the SoC may include one or more processing devices and one or more storage devices).

[0025] As used herein, "processor" or "electronic processor" refers to any device or portion of a device that processes electronic data that can be stored in registers and / or memory and converts that electronic data. Examples of the electronic processor 300 can include one or more digital signal processors (DSPs), application-specific integrated circuits (ASICs), central processing units (CPUs), graphics processing units (GPUs), cryptographic processors (dedicated processors that execute cryptographic algorithms in hardware), server processors, or any other suitable processing device.

[0026] Memory 302 can include one or more local or remote memory devices, such as a random-access memory (RAM) device (e.g., a static RAM (SRAM) device, a magnetic RAM (MRAM) device, a dynamic RAM (DRAM) device, a resistive RAM (RRAM) device, or a conductive-bridging RAM (CBRAM) device), a hard drive-based memory device, a solid-state memory device, a network drive, a cloud drive, or any combination of memory devices. In some implementations, memory 302 can include memory that shares a processor and die. In such embodiments, the memory can be used as cache memory and can include, for example, embedded dynamic random-access memory (eDRAM) or spin transfer torque magnetic random-access memory (STT-MRAM). In some implementations, memory 302 can include a non-transitory computer-readable medium having instructions that, when executed by one or more processors (e.g., electronic processor 300), cause electronic controller 150 to store various applications and data for implementing one or more of the methods described herein or one or more of the portions described herein.

[0027] The electronic controller 150 is connected to the electron beam lenses 106, 116, the deflection unit 118, the detectors 160, 170, 180, and the antenna 194 via the I / O interface 304. The I / O interface 304 may include one or more communication chips, connectors, and / or other hardware and software to govern the communication between the electronic controller 150 and other components. The I / O interface 304 may include an interface circuit for coupling to one or more components using any suitable interface (e.g., Universal Serial Bus (USB) interface, High-Definition Multimedia Interface (HDMI (registered trademark)) interface, Controller Area Network (CAN) interface, Serial Peripheral Interface (SPI) interface, Ethernet interface, wireless interface, or any other suitable interface). For example, the RO interface 304 may include a circuit for managing wireless communication for transferring data between the electronic controller 150. The term "wireless" and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communication channels, etc. that can communicate data through the use of modulated electromagnetic radiation via a non-solid medium. This term does not mean that the associated device does not include any wiring, but in some implementation forms, the associated device may not include wiring.The circuitry included in the I / O interface 304 for managing wireless communications can implement any of several wireless standards or protocols, including, but not limited to, Wi-Fi (IEEE 802.11 family), Institute of Electrical and Electronics Engineers (IEEE) standards including the IEEE 802.16 standard (e.g., IEEE 802.16-2005 Amendment), and any modifications, updates, and / or revisions thereof, the Long-Term Evolution (LTE) project with any modifications, updates, and / or revisions thereof (e.g., the Advanced LTE project, the Ultra-Mobile Broadband (UMB) project (also referred to as “3GPP(®)2”), etc.). In some implementations, the circuitry included in the RO interface 304 for managing wireless communications can operate in accordance with the Global System for Mobile Communication (GSM), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), High Speed Packet Access (HSPA), Evolved HPS (E-HPSA), or an LTE network. In some implementations, the circuitry included in the I / O interface 252 for managing wireless communications can operate in accordance with Enhanced data for GSM Evolution (EDGE), GSM EDGE Radio Access Network (GERAN), Universal Terrestrial Radio Access Network (UTRAN), or Evolved UTRAN (E-UTRAN).In some implementations, the circuitry included in the I / O interface 304 for managing wireless communications can operate according to Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Digital Enhanced Cordless Telecommunications (DECT), Evolution-Data Optimized (EV-DO), and derivatives thereof, as well as any other wireless protocol designated as 3G, 4G, 5G, and beyond. In some implementations, the I / O interface 304 can include one or more antennas (e.g., one or more antenna arrays) for receiving and / or transmitting wired communications.

[0028] FIG. 4 illustrates a block diagram of an exemplary method 400 for controlling a scanning pattern of the scientific instrument 100. The method 400 is described herein as being implemented by the electronic controller 150. However, it should be understood that the method 400 (or a portion thereof) can be implemented by one or more electronic controllers 150 located within the device 100, separate from the device 100, or remote from the device 100, or a combination thereof.

[0029] In step 402, the electronic controller 150 receives, from the antenna 194, a signal indicating the frequency of the electromagnetic interference. For example, the antenna 194 detects the electromagnetic interference generated by the pump 190. The antenna 194 transmits a signal representing the sensed electromagnetic interference to the electronic controller 150. In step 404, the electronic controller 150 adjusts the scanning pattern implemented via the device 100 based on the frequency of the electromagnetic interference. For example, referring to FIG. 5A, the sample S is scanned using a plurality of scan lines 500. The scan lines 500 form a scanning pattern and include an acquisition portion 510 and a flyback portion 512. However, the electromagnetic interference 502 affects the plurality of scan lines 500, resulting in an improperly shaped imaged sample 504.

[0030] Thus, in one implementation, to adjust the scan pattern, the electronic controller 150 aligns the start of each scan line in the plurality of scan lines 500 with the zero crossing 516 of the electromagnetic interference 502, as shown in FIG. 5B. Aligning the scan lines 500 with the zero crossing 516 can be achieved by inserting a delay period 514 after the flyback portion 512 of the scan lines 500. By aligning the scan lines 500 with the zero crossing 516, the effect of the electromagnetic interference 502 is reduced, and the imaged sample 506 is essentially the same as the sample S.

[0031] In another implementation, to adjust the scan pattern, the electronic controller 150 adjusts the dwell time of the electron beam 114. The dwell time is the amount of time the electron beam 114 stays on the sample S for each pixel during the acquisition of the image of the sample S. For example, multiplying the dwell time by the number of pixels in one scan line and adding the flyback time provides the scan time for a single scan line.

[0032] In one example, the electron beam 114 has a dwell time of 200 ns per position and a scan time of approximately 200 - 400 μs per scan line. When the electromagnetic interference has a frequency of 1500 Hz, the resulting scan line time is approximately 667 μs per line. Thus, either 267 μs - 467 μs is lost, and approximately half of the sample exposure time is not used. The time for further repositioning the electron beam at the start of the next scan line also takes, for example, tens of μs, which further increases the time loss.

[0033] Taking this pause period into account, the line time is calculated for each position and adjusted based on the frequency of the electromagnetic interference to maximize the effective exposure time of each scan line. For example, when the electromagnetic frequency has a frequency of 1500 Hz, the line time can be set within a synchronization period of 667 μs. For example, for 960 positions per line and a flyback overhead of 10 μs, the dwell time per position is set to (667 - 10) μs / 960 = 684 ns. For 1920 positions per line, the line time per position is set to (667 - 10) μs / 1920 = 342 ns. The line time per position can be further rounded to the nearest 25 ns value (e.g., 675 ns and 325 ns) to match the timing granularity of the electronic controller 150 and the deflection unit 118.

[0034] The examples described herein mainly target the electromagnetic interference generated by the vacuum pump in the scanning electron microscope, but the influence of the electromagnetic interference generated by other components can also be reduced. For example, the motor that moves the sample holder 110 may generate electromagnetic interference that affects the accuracy of the scanning results. Therefore, the antenna 194 (or an antenna in addition to the antenna 194) can be located on the sample holder 110. As another example, a DC / DC converter or other electronic device within the scientific instrument 100 may generate electromagnetic interference. The frequency of the electromagnetic interference generated by such components may be different from the frequency of the electromagnetic interference generated by the pump 190. For example, the DC / DC converter may generate electromagnetic interference having a frequency of 100 kHz to 200 kHz.

[0035] Additionally, while the examples described herein are primarily directed to considering electromagnetic interference, in some cases the effects of mechanical vibrations within the scientific instrument 10 may also or alternatively be mitigated. For example, instead of the antenna 194, a vibration sensor configured to detect vibrations caused by moving and / or rotating components mounted to the STEM column 102 may be provided. As one implementation for detecting vibrations, the vibration sensor is configured as a motion sensing (MEMS) sensor. The electronic controller 150 receives signals from the MEMS sensor and determines the frequency of the mechanical vibrations based on the signals from the MEMS sensor.

[0036] Accordingly, the implementations described herein provide a system, method, computing and storage devices, and computer-readable media for controlling a scanning pattern of a scientific instrument based on electromagnetic interference. The implementations described herein improve the accuracy of scanning a sample. Accordingly, the implementations disclosed herein provide an improvement to scanning scientific instruments.

[0037] As described above in the detailed description of the invention, reference is made to the accompanying drawings that form a part of this specification, with like numerals indicating like parts throughout, and by way of illustration, implementations that may be practiced are shown. It is to be understood that other implementations may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Accordingly, the detailed description of the invention described above should not be construed in a limiting sense.

[0038] Various operations may be described sequentially as a plurality of distinct actions or operations in a manner that is most helpful in understanding the subject matter disclosed herein. However, the order of description should not be construed as suggesting that these operations necessarily depend on order. Specifically, these operations may not be performed in the order of presentation. The operations described may be performed in a different order than the implementations described. Various additional operations may be performed and / or the operations described may be omitted in additional implementations.

[0039] (Item) Embodiments of the present disclosure are disclosed in the following items.

[0040] Item 1. A charged particle device, comprising: a chamber for supporting a sample; a column coupled to the chamber, the column comprising a charged particle source configured to generate a charged particle beam that travels into the chamber through the column, the charged particle beam being generated according to a scanning pattern; a column; a pump configured to establish a vacuum in the chamber; a sensing device configured to detect a measured value of the frequency of electromagnetic interference generated via the pump; and a controller including an electronic processor and a memory, the controller being configured to receive, from the sensing device, a signal indicating the frequency of the electromagnetic interference and to adjust the scanning pattern based on the frequency of the electromagnetic interference.

[0041] Item 2. The charged particle device according to Item 1, wherein the frequency of the electromagnetic interference is approximately 1000 Hz to 2000 Hz.

[0042] Item 3. The charged particle device according to Item 2, wherein the frequency of the electromagnetic interference is approximately 1500 Hz.

[0043] Item 4. The charged particle device according to any one of Items 1 to 3, wherein the pump includes one or more magnets that generate electromagnetic interference.

[0044] Item 5. The charged particle device according to any one of Items 1 to 4, wherein adjusting the scanning pattern includes aligning the start of each scanning line forming the scanning pattern with a zero crossing of the electromagnetic interference.

[0045] Item 6. The charged particle device according to any one of Items 1 to 5, wherein adjusting the scanning pattern includes inserting a delay period into each scanning line forming the scanning pattern based on the frequency of the electromagnetic interference.

[0046] Item 7. The charged particle device according to any one of Items 1 to 6, wherein the sensing device is configured to amplify the frequency of electromagnetic interference to generate a signal.

[0047] Item 8. The charged particle device according to any one of Items 1 to 7, wherein the sensing device is mounted on a printed circuit board mounted on the surface of the pump.

[0048] Item 9. The charged particle device according to any one of Items 1 to 8, wherein adjusting the scanning pattern includes adjusting the line time of the scanning pattern.

[0049] Item 10. A charged particle device comprising: a chamber for supporting a sample; a column coupled to the chamber, the column comprising a charged particle source configured to generate a charged particle beam that travels into the chamber through the column, the charged particle beam being generated according to a scanning pattern; an antenna configured to detect the frequency of electromagnetic interference generated by the charged particle device; and a controller including an electronic processor and a memory, the controller receiving a signal indicating the frequency of electromagnetic interference from the antenna and configured to align the start of each scanning line forming the scanning pattern with the zero crossing of the electromagnetic interference.

[0050] Item 11. The charged particle device according to Item 10, wherein the frequency of the electromagnetic interference is greater than 1000 Hz.

[0051] Item 12. The charged particle device according to Item 10 or 11, wherein aligning the start of each scanning line with the zero crossing of the electromagnetic interference includes inserting a delay period into each scanning line forming the scanning pattern based on the frequency of the electromagnetic interference.

[0052] Item 13. The charged particle device according to any one of Items 10 to 12, wherein the antenna is configured to amplify the frequency of the electromagnetic interference to generate a signal.

[0053] Item 14. The charged particle device according to any one of Items 10 to 13, wherein the controller is further configured to adjust the dwell time of the scanning pattern based on the frequency of electromagnetic interference.

[0054] Item 15. A method for adjusting a scanning pattern in a charged particle device, the method comprising receiving, from an antenna and using an electronic processor, a signal indicative of the frequency of electromagnetic interference, wherein the electromagnetic interference is generated by a pump configured to establish a vacuum in a chamber supporting a sample, and adjusting, using the electronic processor, the scanning pattern of the charged particle beam based on the frequency of the electromagnetic interference, wherein the charged particle beam is generated by a charged particle source of a column, the column being coupled to the chamber and the charged particle beam traveling through the column into the chamber.

[0055] Item 16. The method according to Item 15, wherein the frequency of the electromagnetic interference is approximately 1000 Hz to 2000 Hz.

[0056] Item 17. The method according to Item 15 or 16, wherein adjusting the scanning pattern comprises aligning, using the electronic processor, the start of each scan line forming the scanning pattern with the zero crossing of the electromagnetic interference.

[0057] Item 18. The method according to any one of Items 15 to 17, wherein adjusting the scanning pattern comprises inserting, using the electronic processor, a delay period into each scan line forming the scanning pattern based on the frequency of the electromagnetic interference.

[0058] Item 19. The method according to any one of Items 15 to 18, further comprising generating a signal by amplifying the frequency of the electromagnetic interference using an antenna.

[0059] Item 20. The method according to any one of Items 15 to 19, wherein adjusting the scanning pattern comprises adjusting, using the electronic processor, the dwell time of the scanning pattern.

Claims

1. 1. A charged particle instrument comprising: a chamber for supporting the sample; a column coupled to the chamber, the column comprising a charged particle source configured to generate a charged particle beam traveling through the column and into the chamber, the charged particle beam being generated according to a scan pattern; a pump configured to establish a vacuum within the chamber; a sensing device configured to detect a measurement of a frequency of electromagnetic interference generated through the pump; a controller including an electronic processor and a memory, said controller comprising: receiving a signal from the sensing device indicative of the frequency of the electromagnetic interference; adjusting the scan pattern based on the frequency of the electromagnetic interference. It is configured as follows: Charged particle instruments.

2. The charged particle instrument of claim 1 , wherein the frequency of the electromagnetic interference is approximately 1000 Hz to 2000 Hz.

3. The charged particle instrument of claim 2 , wherein the frequency of the electromagnetic interference is approximately 1500 Hz.

4. The charged particle instrument of claim 1 , wherein the pump includes one or more magnets that generate the electromagnetic interference.

5. The charged particle instrument of claim 1 , wherein adjusting the scan pattern includes aligning a start of each scan line forming the scan pattern with a zero crossing of the electromagnetic interference.

6. The charged particle instrument of claim 1 , wherein adjusting the scan pattern includes inserting a delay period into each scan line forming the scan pattern based on the frequency of the electromagnetic interference.

7. The charged particle instrument of claim 1 , wherein the sensing device is configured to amplify the frequency of the electromagnetic interference to generate the signal.

8. 10. The charged particle instrument of claim 1, wherein the sensing device is mounted on a printed circuit board mounted to a surface of the pump.

9. The charged particle instrument of claim 1 , wherein adjusting the scan pattern comprises adjusting a line time of the scan pattern.

10. 1. A charged particle instrument comprising: a chamber for supporting the sample; a column coupled to the chamber, the column comprising a charged particle source configured to generate a charged particle beam traveling through the column and into the chamber, the charged particle beam being generated according to a scan pattern; an antenna configured to detect a frequency of electromagnetic interference generated by the charged particle device; a controller including an electronic processor and a memory, said controller comprising: receiving from the antenna a signal indicative of the frequency of the electromagnetic interference; Aligning the beginning of each scan line forming said scan pattern with a zero crossing of said electromagnetic interference. It is configured as follows: Charged particle instruments.

11. The charged particle instrument of claim 10 , wherein the frequency of the electromagnetic interference is greater than 1000 Hz.

12. 11. The charged particle instrument of claim 10, wherein aligning the start of each scan line with a zero crossing of the electromagnetic interference includes inserting a delay period into each scan line forming the scan pattern based on the frequency of the electromagnetic interference.

13. The charged particle instrument of claim 10 , wherein the antenna is configured to amplify the frequency of the electromagnetic interference to generate the signal.

14. The charged particle instrument of claim 10 , wherein the controller is further configured to adjust a dwell time of the scan pattern based on the frequency of the electromagnetic interference.

15. 1. A method for adjusting a scan pattern in a charged particle instrument, comprising: receiving, from the antenna and with an electronic processor, a signal indicative of a frequency of electromagnetic interference, the electromagnetic interference being generated by a pump configured to establish a vacuum in a chamber supporting the specimen; and adjusting, with the electronic processor, a scan pattern of a charged particle beam based on the frequency of the electromagnetic interference, the charged particle beam being generated by a column charged particle source, the column being coupled to the chamber, and the charged particle beam traveling through the column into the chamber. method.

16. The method of claim 15, wherein the frequency of the electromagnetic interference is approximately 1000 Hz to 2000 Hz.

17. The method of claim 15 , wherein adjusting the scan pattern includes aligning, with the electronic processor, a start of each scan line forming the scan pattern with a zero crossing of the electromagnetic interference.

18. 16. The method of claim 15, wherein adjusting the scan pattern includes using the electronic processor to insert a delay period into each scan line forming the scan pattern based on the frequency of the electromagnetic interference.

19. The method of claim 15 , further comprising generating the signal by amplifying the frequency of the electromagnetic interference with the antenna.

20. The method of claim 15 , wherein adjusting the scan pattern includes adjusting, with the electronic processor, a dwell time of the scan pattern.

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