Electron beam position detection and repositioning

Abstract

The multi-channel electrode tube 103 includes at least four deflection plates 300-307. Each of the deflection plates 300-307 is positioned opposite another deflection plate 300-307 across the path of the electron beam 102 passing through the multi-channel electrode tube 103. The voltage difference between the pair of deflection plates 300-307 positioned opposite each other across the path of the electron beam 102 is determined. Then, based on the voltage difference, the position of the electron beam 102 in the multi-channel electrode tube 103 is determined.

Description

Technical Field

[0001] This application claims the priority of U.S. Provisional Patent Application No. 63 / 522,185, filed on June 21, 2023, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to workpiece inspection using an electron beam.

Background Art

[0003] The development of the semiconductor manufacturing industry has placed great demands on yield management, particularly measurement and inspection systems. While the critical dimensions continue to shrink, the industry needs to shorten the time to achieve high-yield and high-value production. By minimizing the total time from detecting to correcting yield problems, the investment profit of semiconductor manufacturers is maximized.

[0004] The manufacture of semiconductor devices such as logic devices and memory devices typically involves processing semiconductor wafers using many manufacturing processes to form various features and multiple levels of the semiconductor device. For example, lithography is a semiconductor manufacturing process that includes transferring a pattern from a reticle to a photoresist disposed on a semiconductor wafer. Additional examples of semiconductor manufacturing processes include, but are not limited to, chemical mechanical polishing (CMP), etching, deposition, and ion implantation. Also, the array of multiple semiconductor devices manufactured on a single semiconductor wafer can be separated into individual semiconductor devices.

[0005] Measurement processes are used at various steps during semiconductor manufacturing for process monitoring and control. Unlike inspection processes, which detect defects on a wafer, measurement processes are used to measure one or more characteristics of a wafer that cannot be determined by existing inspection tools. By using measurement processes, the performance of a process can be determined from one or more characteristics of the wafer. For example, a measurement process can measure the dimensions (e.g., line width, thickness, etc.) of features formed on the wafer during the process. Furthermore, if one or more characteristics of a wafer are outside an acceptable range (e.g., outside a predetermined range for the characteristics), the measurement results of one or more characteristics of the wafer can be used to modify one or more parameters of the process so that additional wafers produced by the process have characteristics within an acceptable range. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent Application Publication No. 2023 / 0028337 [Patent Document 2] U.S. Patent Application Publication No. 2016 / 0020063 [Overview of the project] [Problems that the invention aims to solve]

[0007] Electron beam systems, such as scanning electron microscopes (SEMs), may be used for measurement. These electron beam systems must be precisely aimed at the target. Furthermore, systems using high-power electron beams require alignment to prevent the electron beam from damaging electro-optical components or accidentally irradiating undesirable work surfaces. While electron beam system alignment can be performed manually by technicians, it is complex, time-consuming, and potentially costly. Moreover, manual methods are subjective, meaning alignment may vary depending on the technician performing the alignment.

[0008] Electron beams in SEMs and other electron beam inspection systems also present problems due to the unknown position of the electron beam within the electron beam column housing or scanning area. Drift compensation relies on an interferometer that measures the relative distance between the electron beam column housing and the stage, and compensates for the drift between the electron beam column housing and the stage. Since there is no detector to detect and compensate for the beam's position, the drift of the absolute position of the electron beam relative to the electron beam column housing cannot be detected. Therefore, improved systems and techniques are needed. [Means for solving the problem]

[0009] In a first embodiment, a system is provided. This system comprises an electron beam source that generates an electron beam; a stage configured to hold a workpiece in the path of the electron beam; a multi-channel electrode tube including at least four deflection plates; a power supply electronically communicating with the deflection plates; and a processor electrically communicating with the deflection plates. Each deflection plate is positioned in the multi-channel electrode tube opposite another deflection plate across the path of the electron beam. The processor is configured to determine the voltage difference between a pair of deflection plates positioned opposite each other across the path of the electron beam, and to determine the position of the electron beam in the multi-channel electrode tube based on the voltage difference.

[0010] The deflection plates can be arranged as a square around the path of the electron beam.

[0011] In one example, there are eight deflection plates. The deflection plates may have an octagonal configuration around the path of the electron beam.

[0012] The location may be in the cross-section of a multi-channel electrode tube perpendicular to the electron beam path.

[0013] The processor may be further configured to determine the discrepancy between the position of the electron beam in the multi-channel electrode tube and the position of the electron beam in the multi-channel electrode tube, to determine the voltage scheme of the multi-channel electrode tube to direct the electron beam to the position, and to send an instruction to the power supply to apply the voltage scheme to the deflection plates. The position may be the center of the multi-channel electrode tube. Two of the deflection plates are used to measure the voltage of the voltage difference, and two other deflection plates can receive the voltage scheme.

[0014] In a second embodiment, a method is provided. This method includes generating an electron beam using an electron beam source. The electron beam is directed toward a workpiece on a stage. The electron beam is directed through a multi-channel electrode tube. The multi-channel electrode tube includes at least four deflection plates. Each deflection plate is positioned opposite another deflection plate across the path of the electron beam. A voltage difference is determined between a pair of deflection plates positioned opposite each other across the path of the electron beam. A processor is used to determine the position of the electron beam in the multi-channel electrode tube based on the voltage difference.

[0015] The deflection plates may be arranged as a square around the path of the electron beam.

[0016] In one example, there are eight deflection plates. The deflection plates may have an octagonal configuration around the path of the electron beam.

[0017] The location may be in the cross-section of a multi-channel electrode tube perpendicular to the electron beam path.

[0018] This method may further include using a processor to determine the discrepancy between the position of the electron beam in the multi-channel electrode tube and the position of the electron beam in the multi-channel electrode tube, using the processor to determine the voltage scheme of the multi-channel electrode tube to direct the electron beam to the position, and applying the voltage scheme to a deflection plate. The position may be the center of the multi-channel electrode tube. Two of the deflection plates may be used for measuring the voltage of the voltage difference, and two different deflection plates may be used for the voltage scheme.

[0019] In a third embodiment, a non-temporary computer-readable storage medium is provided. This non-temporary computer-readable storage medium includes one or more programs for performing steps on one or more computing devices. The steps include receiving the results of voltage measurements of a pair of deflection plates in a multi-channel electrode tube as an electron beam is directed through the multi-channel electrode tube, determining the voltage difference between the pair of deflection plates, and determining the position of the electron beam in the multi-channel electrode tube based on the voltage difference. Each deflection plate is positioned opposite another deflection plate across the path of the electron beam.

[0020] The steps may further include determining the discrepancy between the position of the electron beam in the multi-channel electrode tube and the positioning of the electron beam in the multi-channel electrode tube, determining the voltage scheme of the multi-channel electrode tube to direct the electron beam to the positioning, and sending a command to apply the voltage scheme to the deflection plate.

[0021] For a deeper understanding of the nature and purpose of this disclosure, please refer to the following detailed description in conjunction with the attached drawings. [Brief explanation of the drawing]

[0022] [Figure 1]A block diagram of a system according to the present disclosure. [Figure 2] A cross-sectional view of an embodiment of a multi-channel electron tube according to the present disclosure. [Figure 3] A cross-sectional view of another embodiment of a multi-channel electron tube according to the present disclosure. [Figure 4] A diagram including a voltage chart showing the operation of a multi-channel electron tube corresponding to the embodiment of FIG. 3 when an electron beam moves over time. [Figure 5] A diagram including a voltage chart showing the operation of a multi-channel electron tube corresponding to the embodiment of FIG. 3 when an electron beam moves over time. [Figure 6] A diagram including a voltage chart showing the operation of a multi-channel electron tube corresponding to the embodiment of FIG. 3 when an electron beam moves over time. [Figure 7] A diagram including a chart showing the operation of a multi-channel electron tube corresponding to the embodiment of FIG. 3. [Figure 8] A diagram including a chart showing the operation of a multi-channel electron tube corresponding to the embodiment of FIG. 3.

MODE FOR CARRYING OUT THE INVENTION

[0023] The subject matter of the claims is described with respect to specific embodiments, but other embodiments (including embodiments that do not provide all of the advantages and features described herein) are also within the scope of the present disclosure. Also, various structural, logical, process step, and electronic changes are possible without departing from the scope of the present disclosure. Accordingly, the scope of the present disclosure is defined only by reference to the appended claims.

[0024] In embodiments disclosed herein, electron beam positioning errors in an electron beam inspection system are detected and compensated for. By determining the measurement results of the absolute placement and position of the electron beam relative to the electron beam column housing, the electron beam inspection system can provide more accurate alignment measurement results. Measuring the absolute position of the electron beam relative to the electron beam column housing enables sub-nanometer level alignment measurements that are not possible with interferometers and electron beam steering.

[0025] Figure 1 is a block diagram of the electron beam system 100. This system comprises an electron beam source 101 that generates an electron beam 102. The electron beam 102 is directed toward a workpiece 105 held on a stage 104. By using the electron beam 102, an image of the workpiece 105 can be generated, which can then be used to inspect the workpiece 105.

[0026] The electron beam source 101 may include, for example, a cathode source or an emitter tip. The electron beam source 101 may be coupled with other elements such as a gun lens, anode, beam limiting aperture, gate valve, beam current selecting aperture, objective lens, or scanning subsystem, all of which may include any suitable elements known in the art.

[0027] The electron beam 102 is directed through a multi-channel electrode tube 103. As shown in Figures 2 and 3, the multi-channel electrode tube 103 may include at least four deflection plates. Each deflection plate of the multi-channel electrode tube 103 is positioned opposite another deflection plate across the path of the electron beam 102. The deflection plates of the multi-channel electrode tube 103 are in electronic communication with the power supply 105 and the processor 106. The processor 106 may also be in electronic communication with the power supply 105.

[0028] Figure 2 shows four deflection plates, and Figure 3 shows eight deflection plates, but other numbers of deflection plates are also possible. For example, six, ten, twelve, fourteen, or sixteen deflection plates may be used. Around the electron beam 102, there are at least two deflection plates (i.e., pairs) in each vertical axis direction. In one example, there are an even number of deflection plates, and the deflection plates are grouped as pairs flanking the path of the electron beam 102. Each deflection plate may or may not have the same dimensions. Deflection plates opposite each other across the electron beam 102 may have the same dimensions.

[0029] Electrons (e.g., secondary electrons) from the workpiece 105 can be focused by one or more elements onto a detector 107 that images the workpiece 105. These one or more elements may include, for example, a scanning subsystem. The detector 107 may communicate electronically with a processor 106.

[0030] Furthermore, various components of the electron beam system 100 can be positioned inside the vacuum chamber. The electron beam 102 may be generated under vacuum or near-vacuum conditions. The vacuum chamber can be, for example, an electron column.

[0031] Figure 2 is a cross-sectional view of one embodiment of the multi-channel electrode tube 103. As seen in Figure 2, the multi-channel electrode tube 103 includes four deflection plates 200-203 arranged in a square. Deflection plate 200 is opposite deflection plate 202 to the electron beam 102. Deflection plate 201 is opposite deflection plate 203 to the electron beam 102. Deflection plates 200-203 are electronically connected to the power supply 105 and the processor 106, respectively. The electron beam 102 passes through the multi-channel electrode tube 103 (i.e., along the z-axis as shown in the figure).

[0032] Figure 3 is a cross-sectional view of another embodiment of the multi-channel electrode tube 103. As seen in Figure 3, the multi-channel electrode tube 103 includes eight deflection plates 300-307 arranged in an octagonal configuration. Deflection plate 300 is opposite deflection plate 304 to the electron beam 102. Deflection plate 301 is opposite deflection plate 305 to the electron beam 102. Deflection plate 302 is opposite deflection plate 306 to the electron beam 102. Deflection plate 303 is opposite deflection plate 307 to the electron beam 102. Deflection plates 300-307 are electronically connected to the power supply 105 and the processor 106, respectively. The electron beam 102 passes through the multi-channel electrode tube 103 (i.e., the z-axis as shown in the figure).

[0033] Figure 2 shows four deflection plates 200-203, and Figure 3 shows eight deflection plates 300-307, but other numbers of deflection plates may be used. By having an even number of deflection plates in the multi-channel electrode tube 103, each deflection plate is opposed to another deflection plate with respect to the electron beam 102. The deflection plates can be arranged in a polygonal or circular configuration.

[0034] The processor 106 may be communication-coupled to the power supply 105 and / or the deflection plates. The processor 106 may include one or more processors configured to perform any of a variety of process steps. In an embodiment, the processor 106 is configured to provide one or more control signals to one or more deflection plates, which are configured to perform one or more adjustments.

[0035] One or more processors of processor 106 may include any processors known in the art. For the purposes of this disclosure, the term “processor” may be broadly defined to include any device having one or more processing or logic elements (e.g., one or more microprocessor devices, one or more application-specific integrated circuit (ASIC) devices, one or more field-programmable gate arrays (FPGAs), or one or more digital signal processors (DSPs)). In this sense, one or more processors may include any device configured to execute algorithms and / or instructions (e.g., program instructions stored in memory). In one embodiment, one or more processors may be embodied as a desktop computer, a mainframe computer system, a workstation, an imaging computer, a parallel processor, a networked computer, or any other computer system configured to execute a program configured to operate the electron beam system 100 or a program configured to work in conjunction with the electron beam system 100, as described throughout this disclosure. Furthermore, various subsystems of the electron beam system 100 may include processors or logic elements suitable for performing at least some of the steps described in this disclosure. Therefore, the above description should be interpreted as illustrative rather than limiting to embodiments of the present disclosure. Furthermore, the steps described throughout the present disclosure may be performed by a single processor or by multiple processors. Also, the processor 106 may include one or more processors housed in a common housing or multiple housings. Thus, any processor 106 or combination of processors 106 may be packaged separately as a module suitable for integration into the electron beam system 100. Furthermore, the processor 106 may analyze data received from the electron beam system 100 and supply the data to additional components within or outside the electron beam system 100.

[0036] The memory medium may include any storage medium known in the art and suitable for storing program instructions executable by one or more associated processors. For example, the memory medium may include non-temporary memory medium. Other examples of the memory medium may include, but are not limited to, read-only memory (ROM), random access memory (RAM), magnetic or optical memory devices (e.g., disks), magnetic tapes, solid drives, etc. Furthermore, the memory medium may be housed in a common processor housing together with one or more processors. In one embodiment, the memory medium may be located remotely from the physical location of one or more processors. For example, one or more processors of processor 106 may access remote memory (e.g., a server) that is accessible over a network (e.g., the Internet, an intranet, etc.).

[0037] A user interface may be communicate-coupled to the processor 106. In embodiments, the user interface includes a display used to display data from the electron beam system 100 to the user. The user interface display may include any display known in the art. For example, the display may include, but is not limited to, a liquid crystal display (LCD), an organic light-emitting diode (OLED) based display, or a cathode ray tube (CRT) display. Those skilled in the art will recognize that any display device that can be integrated with the user interface is suitable for embodiments of the disclosure. In embodiments, the user may input selections and / or instructions corresponding to the data displayed to the user via a user input device of the user interface.

[0038] The processor 106 can determine the voltage difference between a pair of deflection plates (e.g., deflection plates 200 and 202 or deflection plates 303 and 307) positioned opposite each other across the path of the electron beam 102. The electron beam 102 can induce charges on the deflection plates by utilizing the physical effect of Miller charges. One or more voltmeters may be used to measure the voltage difference on the pair of deflection plates. Information from the voltmeters can then be transmitted to the processor 106. The voltage difference indicates the position of the electron beam 102 between the pair of deflection plates. The processor 106 can then determine the position of the electron beam 102 in the multi-channel electrode tube 103 based on the voltage difference. When the voltage difference is zero, the electron beam 102 is at the center of the multi-channel electrode tube 103 (e.g., in the xy plane). Additionally, a function can be determined that converts the voltage difference to a distance from the center (e.g., 1 to 100 μm) for a particular tool and / or a particular parameter of the electron beam 102. In another example, the position of the electron beam 102 in the multi-channel electrode tube 103 is center / off-center or zero / off-zero between a pair of deflection plates, without a specific distance from the center.

[0039] In one embodiment, the processor 106 can determine the discrepancy between the position of the electron beam 102 in the multi-channel electrode tube 103 and the positioning of the electron beam 102 in the multi-channel electrode tube 103. The processor can then determine the voltage scheme of the multi-channel electrode tube 103 to direct the electron beam 102 to the positioning and send an instruction to the power supply 105 to apply the voltage scheme to the deflection plates. This positioning may be, for example, the center of the multi-channel electrode tube 103. In one example, two of the deflection plates are used to measure the voltage difference and two different deflection plates receive the voltage scheme, but other configurations are also possible.

[0040] Figures 4 to 6 include voltage charts showing the operation of a multi-channel electrode tube corresponding to the embodiment in Figure 3. In Figure 4, the electron beam 102 is at the center of the multi-channel electrode tube 103. The chart shows the voltage over time. In this example, the voltage (V) is the voltage difference between the (shaded) deflection plates 302 and 306. The electron beam 102 is at the center between the deflection plates 302 and 306. Therefore, the voltage is shown as zero on the chart. The voltage difference becomes either positive or negative as the electron beam 102 moves away from the center. Thus, the voltage difference corresponds to the position of the electron beam 102 in the multi-channel electrode tube 103. This voltage difference can then be determined using the processor 106.

[0041] In Figure 5, the electron beam 102 has moved to the right of its past position in Figure 4 (indicated by the dotted line). Here, the electron beam 102 is closer to the deflection plate 306 than the deflection plate 306. As a result, the voltage difference has changed, as shown in the chart. After the movement of the electron beam 102, the voltage difference is positive. This voltage difference can then be determined using the processor 106.

[0042] In Figure 6, the electron beam 102 has moved to the left relative to its past position in Figure 5 (indicated by the dotted line). Here, the electron beam 102 is closer to the deflection plate 306 than to the deflection plate 302. As a result, the voltage difference has changed, as shown in the chart. After the movement of the electron beam 102, the voltage difference is negative. This voltage difference can then be determined using the processor 106.

[0043] Although we have shown this for two of the deflection plates, by determining the voltage difference for two or more pairs of deflection plates, it is possible to obtain a two-dimensional measurement result of the position of the electron beam 102 in the cross-section (for example, the xy plane) of the multi-channel electrode tube 103. The position of the electron beam 102 can be linearly determined by each pair of deflection plates.

[0044] Figures 7 and 8 include charts illustrating the operation of the multi-channel electrode tube corresponding to the embodiment in Figure 3. Figures 7 and 8 include a grid showing the two-dimensional center of the multi-channel electrode tube 103. The electron beam 102 can be positioned in the multi-channel electrode tube 103 as the center of the multi-channel electrode tube 103. Naturally, other positions are also possible for the electron beam 102. The positioning is not limited to the center of the multi-channel electrode tube 103 or the center of the area inside the deflection plate. The positioning may be determined by the imaging application of the electron beam 102, the type of workpiece to be imaged, the system configuration, the calibration of other optical components of the system, or other variables.

[0045] In Figure 7, the processor 106 determines the position of the electron beam 102 in the multi-channel electrode tube 103. For example, the position of the electron beam 102 can be determined by using the voltage difference between the deflection plates 300, 302, 304, and 306 (shaded in Figure 7). In Figure 7, the path of the electron beam 102 is equally positioned between the deflection plates 302 and 306, satisfying the position specification on the horizontal axis. However, the path of the electron beam 102 does not satisfy the position specification on the vertical axis between the deflection plates 300 and 304. The electron beam 102 is closer to deflection plate 300 than to deflection plate 304. The deviation between the electron beam 102 and the position specification is indicated by arrow 400.

[0046] The deviation of the electron beam 102 can be measured with respect to the center of the electron beam 102 or to the outer periphery of the electron beam 102. In the examples in Figures 7 and 8, the center of the electron beam 102 is used.

[0047] Subsequently, the processor 106 can determine the voltage scheme of the multi-channel electrode tube 103 to direct the electron beam 102 to the target. As shown in Figure 8, different voltages are applied to the deflection plates 301, 303, 305, and 307 to direct the electron beam 102 from its past position (shown by the dotted line) to the target at the center of the grid. In one example, this is a voltage that minimizes the voltage difference until it becomes zero. This operation can be part of a control loop that maintains the electron beam 102 at the target by minimizing or eliminating the voltage difference. The processor 106 can change the voltage scheme until the electron beam 102 matches the target.

[0048] In the examples in Figures 7 and 8, different deflection plate pairs are used for measuring the voltage of the voltage difference and for applying the voltage scheme.

[0049] An additional embodiment, as disclosed herein, relates to a non-temporary computer-readable medium for storing program instructions executable on a processor for performing a computer-executed method of electron beam calibration. The processor 106 may include memory in an electronic data storage unit or other electronic data storage medium having a non-temporary computer-readable medium containing program instructions executable on the processor 106. The computer-executed method may include any step of any method described herein. For example, the processor 106 may be programmed to perform some or all of the steps in Figures 4-6 or Figures 7 and 8. In one example, the processor 106 may receive the results of voltage measurements of a pair of deflection plates in a multi-channel electrode tube as the electron beam is directed through the multi-channel electrode tube. Each deflection plate is positioned opposite another deflection plate across the path of the electron beam. The processor 106 may then determine the voltage difference between the pair of deflection plates and, based on the voltage, determine the position of the electron beam in the multi-channel electrode tube. Furthermore, the processor 106 may determine the discrepancy between the position of the electron beam in the multi-channel electrode tube and the positioning of the electron beam in the multi-channel electrode tube, determine the voltage scheme of the multi-channel electrode tube to direct the electron beam to the positioning, and send an instruction to apply the voltage scheme to the deflection plate. The memory in the electronic data storage unit or other electronic data storage medium may be a storage medium such as a magnetic or optical disk, non-volatile memory, solid memory, magnetic tape, or any other suitable non-temporary computer-readable medium known in the art.

[0050] Program instructions may be implemented in any of the following ways, including, in particular, procedural-based techniques, component-based techniques, and / or object-oriented techniques. For example, program instructions may be implemented, as needed, by ActiveX controls, C++ objects, JavaBeans, Microsoft Foundation Classes (MFC), Streaming SIMD Extensions (SSE), or other techniques or methods.

[0051] While the above disclosure pertains to electron beams, the embodiments disclosed herein can also be used for ion beams. The electron beam source can be replaced with any suitable ion beam source known in the art. The power acquisition subsystem may also be any other suitable ion beam-based power acquisition subsystem, such as those included in commercially available focused ion beam (FIB) systems, helium ion microscope (HIM) systems, and secondary ion mass spectrometry (SIMS) systems. Thus, a variety of particle beams can benefit from the embodiments disclosed herein.

[0052] While this disclosure has described one or more specific embodiments, it is understood that other embodiments of this disclosure are also possible without departing from the scope of this disclosure. Therefore, this disclosure is considered to be limited only by the appended claims and their reasonable interpretation.

Claims

1. An electron beam source that generates an electron beam, A stage configured to hold a workpiece in the path of the electron beam, A multi-channel electrode tube comprising at least four deflection plates, wherein each of the deflection plates is arranged in the multi-channel electrode tube opposite to another deflection plate, with the path of the electron beam in between. The power supply that is electronically connected to the deflection plate, The processor is electrically connected to the deflection plate, Determining the voltage difference between a pair of deflection plates arranged opposite each other across the path of the electron beam, Based on the voltage difference, the position of the electron beam in the multi-channel electrode tube is determined, A processor configured to perform the following actions: A system characterized by comprising the following features.

2. The system according to claim 1, characterized in that the deflection plate is arranged as a square around the path of the electron beam.

3. The system according to claim 1, characterized in that eight deflection plates are present.

4. The system according to claim 3, characterized in that the deflection plate has an octagonal configuration around the path of the electron beam.

5. The system according to claim 1, characterized in that the position is in the cross-section of the multi-channel electrode tube perpendicular to the path of the electron beam.

6. The system according to claim 1, wherein the processor is Determining the discrepancy between the position of the electron beam in the multi-channel electrode tube and the specified position of the electron beam in the multi-channel electrode tube, Determining the voltage scheme of the multi-channel electrode tube that directs the electron beam to the designated position, Sending a command to the power supply to apply the voltage scheme to the deflection plate, A system characterized by being further configured to perform the following actions.

7. The system according to claim 6, characterized in that the position designation is the center of the multi-channel electrode tube.

8. The system according to claim 6, wherein two of the deflection plates are used to measure the voltage of the voltage difference, and two different deflection plates receive the voltage scheme.

9. Generating an electron beam using an electron beam source, The electron beam is directed toward the workpiece on the stage, The electron beam is directed through a multi-channel electrode tube, wherein the multi-channel electrode tube includes at least four deflection plates, and each of the deflection plates is positioned opposite another deflection plate across the path of the electron beam. Determining the voltage difference between a pair of deflection plates arranged opposite each other across the path of the electron beam, Using a processor, the position of the electron beam in the multi-channel electrode tube is determined based on the voltage difference, A method characterized by including the following.

10. A method according to claim 9, characterized in that the deflection plate is arranged as a square around the path of the electron beam.

11. A method according to claim 9, characterized in that eight deflection plates are present.

12. A method according to claim 11, characterized in that the deflection plate has an octagonal configuration around the path of the electron beam.

13. A method according to claim 9, characterized in that the position is in the cross-section of the multi-channel electrode tube perpendicular to the path of the electron beam.

14. The method according to claim 9, Using the aforementioned processor, the discrepancy between the position of the electron beam in the multi-channel electrode tube and the specified position of the electron beam in the multi-channel electrode tube is determined. Using the aforementioned processor, the voltage scheme of the multi-channel electrode tube that directs the electron beam to the designated position is determined, Applying the aforementioned voltage scheme to the deflection plate, A method characterized by further comprising:

15. A method according to claim 14, characterized in that the position designation is the center of the multi-channel electrode tube.

16. A method according to claim 14, characterized in that two of the deflection plates are used for measuring the voltage of the voltage difference, and two different deflection plates are used in the voltage scheme.

17. The following steps are performed on one or more computing devices: The steps include receiving the voltage measurement results of a pair of deflection plates in a multi-channel electrode tube when an electron beam is directed through the multi-channel electrode tube, wherein each of the deflection plates is arranged opposite to another deflection plate across the path of the electron beam, and The steps include determining the voltage difference between the pair of deflection plates, A step of determining the position of the electron beam in the multi-channel electrode tube based on the voltage, A non-temporary computer-readable storage medium characterized by containing one or more programs for executing [a certain action].

18. A non-temporary computer-readable storage medium according to claim 17, wherein the step is: Determining the discrepancy between the position of the electron beam in the multi-channel electrode tube and the specified position of the electron beam in the multi-channel electrode tube, Determining the voltage scheme of the multi-channel electrode tube that directs the electron beam to the designated position, Sending a command to apply the aforementioned voltage scheme to the deflection plate, A non-temporary computer-readable storage medium characterized by further including the following.

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