Electron beam scanning control method and device and storage medium

Abstract

The invention provides an electron beam scanning control method and device and a storage medium. The method comprises the steps that a scanning instruction containing a row stepping voltage value and the maximum scanning row number of a sub-scanning area is acquired; in the moving state of the moving platform, controlling the electron beam to scan from the first sub-scanning area in the direction opposite to the moving direction of the moving platform based on the row stepping voltage value; after the scanning line number reaches the maximum scanning line number of the sub-scanning area, the electron beam is shifted to the first line of the next sub-scanning area for continuous scanning; and the process is repeated until all the to-be-scanned targets are scanned. Therefore, scanning can be carried out at intervals of a plurality of rows by adjusting the row stepping voltage value, so that the charge phenomenon in the scanning process is reduced, and the definition of a scanned image and the scanning efficiency are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor defect detection technology, and in particular to an electron beam scanning control method, device, scanning electron microscope, computer program product and computer readable storage medium. Background Art

[0002] In the field of semiconductor defect detection, detection equipment with electron beam scanning function is usually used to detect defects in semiconductor products. For example, a scanning electron microscope is used to emit an electron beam to the sample under test, receive the electron beam reflected by the surface of the sample under test, and form a scanned image of the sample under test based on the reflected electron beam, thereby obtaining the microscopic morphology of the sample under test to identify the defects of the sample under test.

[0003] In the existing scanning method, the electron beam will cause a charging effect on the surface of the sample being tested during the scanning process, resulting in a blurred scan image and affecting the accuracy of the defect detection results. Summary of the invention

[0004] In view of this, the present application provides an electron beam scanning control method, device, scanning electron microscope, computer program product and computer readable storage medium, which can reduce the occurrence of charging phenomenon during the scanning process and improve the clarity of the scanned image and the scanning efficiency.

[0005] In a first aspect, an embodiment of the present application provides an electron beam scanning control method, comprising: obtaining a scanning instruction, wherein the scanning instruction includes a row step voltage value for controlling a scanning offset in a column direction of the electron beam and a maximum number of scanning rows in a sub-scanning area; when a moving platform carrying a target to be scanned is in a moving state, controlling the electron beam to scan from a first sub-scanning area of ​​the target to be scanned based on the row step voltage value; the sub-scanning area is a scanning area obtained by sampling the target to be scanned at intervals of N rows, N being an integer greater than or equal to 1, and the moving direction of the moving platform is opposite to the column direction during electron beam scanning; after the number of scanning rows reaches the maximum number of scanning rows in the sub-scanning area, offsetting the electron beam to the first row of the next sub-scanning area of ​​the target to be scanned, and controlling the electron beam to scan the next sub-scanning area based on the row step voltage value; after the number of scanning rows reaches the maximum number of scanning rows in the sub-scanning area, determining whether all scanning operations of the target to be scanned are completed; if all scanning operations of the target to be scanned are not completed, continuing to perform scanning operations of other sub-scanning areas according to the above method until all scanning of the target to be scanned is completed.

[0006] In a second aspect, an embodiment of the present application provides an electron beam scanning control device, comprising: an instruction acquisition module, used to acquire a scanning instruction, wherein the scanning instruction includes: a row step voltage value for controlling the scanning offset of the electron beam in the column direction and a maximum number of scanning rows in a sub-scanning area; a scanning module, used to control the electron beam to start scanning from the first sub-scanning area of ​​the target to be scanned based on the row step voltage value when a moving platform carrying the target to be scanned is moving; the sub-scanning area is a scanning area obtained by sampling every N rows in the target to be scanned, wherein N is an integer greater than or equal to 1, and the moving direction of the moving platform is related to the electron beam scanning time. The column direction is opposite; an offset control module is used to offset the electron beam to the first row of the next sub-scanning area of ​​the target to be scanned after the number of scanning rows reaches the maximum number of scanning rows of the sub-scanning area, so that the scanning module controls the electron beam to scan the next sub-scanning area based on the row step voltage value; a judgment module is used to judge whether all scanning operations of the target to be scanned are completed after the number of scanning rows reaches the maximum number of scanning rows of the sub-scanning area; the offset control module and the scanning module are also used to continue to execute the scanning operations of other sub-scanning areas when all scanning operations of the target to be scanned are not completed until all scanning of the target to be scanned is completed.

[0007] In a third aspect, an embodiment of the present application provides a scanning electron microscope, including the electron beam scanning control device provided by any embodiment of the present application.

[0008] In a fourth aspect, an embodiment of the present application provides a computer program product, which includes computer executable instructions, wherein when the computer executable instructions are executed by a processor, the steps of the electron beam scanning control method provided in any embodiment of the present application are implemented.

[0009] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a computer executable program is stored, wherein when the computer executable program is executed by a processor, the steps of the electron beam scanning control method provided in any embodiment of the present application are implemented.

[0010] In summary, the electron beam scanning control method, device, scanning electron microscope, computer program product and computer readable storage medium provided by the embodiments of the present application have at least the following beneficial effects: obtaining a scanning instruction including a row step voltage value and a maximum number of scanning rows in a sub-scanning area; when the moving platform is in a moving state, the electron beam is controlled to scan in the reverse direction of the moving platform from the first sub-scanning area based on the row step voltage value; after the number of scanning rows reaches the maximum number of scanning rows in the sub-scanning area, the electron beam is shifted to the first row of the next sub-scanning area to continue scanning; repeat this process until all the targets to be scanned are scanned. In this way, the row step voltage value can be adjusted to achieve scanning at intervals of several rows, thereby reducing the occurrence of charging phenomena during the scanning process, improving the clarity of the scanned image, and enhancing the scanning quality, thereby ensuring the accuracy of defect detection.

[0011] In addition, the present application combines the movement of the motion platform so that the scanning of the electron beam in the column direction is opposite to the movement direction of the motion platform, thereby further improving the scanning speed through the combined motion mode, thereby improving the overall scanning efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 A schematic structural diagram of a scanning electron microscope provided in an embodiment of the present application is shown;

[0014] Figure 2 A schematic flow chart of an electron beam scanning control method provided in an embodiment of the present application is shown;

[0015] Figure 3 A schematic structural diagram of an electron beam scanning control device provided in an embodiment of the present application is shown;

[0016] Figure 4 A schematic diagram showing the structure of a computer-readable storage medium provided in an embodiment of the present application is shown;

[0017] Figure 5 A schematic diagram showing the structure of a computer program product provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0018] In order to make the above and other features and advantages of the present application more clear, the present application is further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0019] In the following description, many specific details are set forth to provide a thorough understanding of the present application. However, it is apparent to those skilled in the art that specific details need not be adopted to practice the present application. In other cases, well-known steps or operations are not described in detail to avoid blurring the present application.

[0020] Before introducing the embodiments of the present application in detail, the technical terms involved in the present application are first explained.

[0021] The charging effect means that when the electron beam irradiates the sample surface, the excess charge cannot be conducted away in time, and charge accumulation will form on the sample surface, generating an electrostatic field that interferes with the incident electron beam and the emission of secondary electrons, thereby affecting the scanning results.

[0022] At present, the scanning method adopted by most scanning electron microscopes is to scan the target line by line by moving the electron beam. The above scanning method not only makes it easy for the surface of the scanned target to have a charging effect, but also takes a long time to complete the scanning and has a low scanning efficiency.

[0023] In view of this, an embodiment of the present application provides a scanning electron microscope, Figure 1 A schematic diagram of the structure of a scanning electron microscope provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the scanning electron microscope 10 may include an electron beam scanning control device 11 and a motion platform 12 .

[0024] The motion platform 12 is used to carry the scanning target horizontally and moves at a constant speed under the control of the electron beam scanning control device 11 so that the scanning target moves in the opposite direction of the column direction.

[0025] In one embodiment, the electron beam scanning control device 11 may include an emitter, an electron deflector, a detector, and a controller. The controller is used to control the emitter to emit an electron beam, and is also used to apply a deflection voltage to the electron polarizer to control the deflection of the electron beam, and receive the electron beam detected by the detector to generate a scanned image of the target to be scanned. Among them, the electronic polarizer includes a first deflector in the X direction and a second deflector in the Y direction. The X direction is the row direction of the target to be scanned, and the Y direction is the column direction of the target to be scanned. The first deflector is used to control the electron beam to deflect in the X direction, and the second deflector is used to control the electron beam to deflect in the Y direction.

[0026] The electron beam scanning control device 11 can be used to execute any electron beam scanning control method provided in the embodiments of the present application, and can realize continuous interlaced scanning of the scanning target, thereby reducing the charging phenomenon and improving the clarity of the scanned image. The combined motion mode not only improves the flexibility of the scanning, but also allows a larger sample area to be scanned in a shorter time, thereby significantly improving the detection efficiency.

[0027] In some embodiments of the present application, the scanning electron microscope may also be connected to a user terminal. The user terminal is used to send a scanning command to the electron beam scanning control device 11 and receive and store the scanning image data collected by the electron beam scanning control device 11.

[0028] Another aspect of the present application provides an electron beam scanning control method, which is applied to Figure 1 The electron beam scanning control device 11 is shown. Figure 2 A schematic flow chart of an electron beam scanning control method provided in an embodiment of the present application is shown as follows: Figure 2 As shown, the electron beam scanning control method includes the following steps.

[0029] S21, obtaining a scanning instruction, wherein the scanning instruction includes a row step voltage value for controlling a scanning offset of an electron beam in a column direction and a maximum number of scanning rows in a sub-scanning area.

[0030] The scanning instructions involved in the embodiment of the present application at least include: a row step voltage value for controlling the scanning offset of the electron beam column direction and a maximum number of scanning rows in the sub-scanning area.

[0031] It is understandable that the scanning instruction may also include other existing parameters, such as scanning speed, current intensity of the electron beam, etc., which are not specifically limited in the present application.

[0032] Among them, the sub-scanning area is a scanning area obtained by sampling every N lines of the target to be scanned, and N is an integer greater than or equal to 1. The first sub-scanning area is a scanning area obtained by sampling every N lines starting from the first line of the target to be scanned, the second sub-scanning area is a scanning area obtained by sampling every N lines starting from the second line of the target to be scanned, and the Nth sub-scanning area is a scanning area obtained by sampling every N lines starting from the Nth line of the target to be scanned. In other words, the sub-scanning area refers to a series of smaller scanning areas into which the target to be scanned is divided according to specific intervals (i.e., every N lines). The target to be scanned may include at least two sub-scanning areas.

[0033] For example, when there are 512 rows of the target to be scanned and N is 1, the target to be scanned may include two sub-scanning areas. The first sub-scanning area includes the 1st row, the 3rd row, ..., the 511th row. That is, the 1st row of the first sub-scanning area is the 1st row of the target to be scanned, the 2nd row of the first sub-scanning area is the 3rd row of the target to be scanned, and so on. The 256th row of the first sub-scanning area is the 511th row of the target to be scanned. The second sub-scanning area includes the 2nd row, the 4th row, ..., the 512th row. That is, the 1st row of the second sub-scanning area is the 2nd row of the target to be scanned, the 2nd row of the second sub-scanning area is the 4th row of the target to be scanned, and so on. The 256th row of the second sub-scanning area is the 512th row of the target to be scanned.

[0034] The maximum number of scanning lines of the sub-scanning area involved in the embodiment of the present application can be determined by the total number of scanning lines of the target to be scanned and the value N. For example, the maximum number of scanning lines of the sub-scanning area = the total number of scanning lines of the target to be scanned / N+1.

[0035] The row step voltage value involved in the embodiment of the present application can be an N-row step voltage value, that is, a voltage value required for the electron beam to shift by N rows. The row step voltage value can be determined according to the characteristics of the electron deflector, which is related to the number of rows of the electron beam interval. For example, if the electron beam scans every N rows, the corresponding row step voltage value is the voltage value required for the shift by N rows.

[0036] The target to be scanned in the embodiment of the present application may be a complete sample or a partial area of ​​the sample. If the sample is relatively large, the sample may be divided into a plurality of areas, each of which is a target to be scanned. Optionally, the sample may be a wafer.

[0037] In an embodiment of the present application, the scanning instruction may be sent by the user end to the electron beam scanning control device 11 , or may be directly set and generated by the user on the operation interface of the electron beam scanning control device 11 .

[0038] S22, when the moving platform carrying the target to be scanned is in a moving state, the electron beam is controlled to start scanning from the first sub-scanning area of ​​the target to be scanned based on the row step voltage value.

[0039] The moving state of the moving platform carrying the target to be scanned involved in the embodiment of the present application refers to the moving platform carrying the target to be scanned, and the moving platform is in a moving state. The moving direction of the moving platform is opposite to the column direction when the electron beam is scanning, wherein the column direction when the electron beam is scanning refers to the column scanning direction of the electron beam. That is, if the column direction is vertically downward, then the moving direction of the moving platform is vertically upward.

[0040] It should be noted that the electron beam scanning control device 11 can control the movement state of the motion platform through motion parameters. The motion parameters can be pre-set in the electron beam scanning control device 11 or obtained by the electron beam scanning control device 11 from the user.

[0041] In one embodiment, the motion parameter may include a position coordinate sequence, and the electron beam scanning control device 11 controls the position and speed of the motion platform according to the position coordinate sequence.

[0042] In one embodiment of the present application, the moving speed of the motion platform can be determined according to the time for the electron beam to scan a row. That is, during the time for the electron beam to scan a row, the moving distance of the motion platform is less than the column size of a scanned row. Among them, the time for the electron beam to scan a row is related to the delay time of the row scan, the number of row pixels, the average number of points, the average number of rows, and the pixel size. The time for the electron beam to scan a row can be expressed as the following formula.

[0043]

[0044] Among them, Time represents the time for the electron beam to scan a line, PixelSize represents the pixel size, ImageSize represents the number of pixels in a line, PixelAvg represents the average number of points, LineAvg represents the average number of lines, and delayTime represents the delay time.

[0045] In one embodiment of the present application, the electron beam scanning control device 11 controls the moving platform 12 to move in the opposite direction of the column direction during electron beam scanning, and controls the electron beam to start row scanning when it reaches the first row of the first sub-scanning area. After the first row scan is completed, a voltage equal to the row step voltage value is applied to the electron deflector to control the electron beam to offset to the second row of the first sub-scanning area to start scanning. Since the moving platform and the electron beam move in opposite directions, when the electron beam moves to the next row after scanning the first row, the accumulated movement of the moving platform can realize the control of the electron beam to skip N rows and start row scanning from the N+1th row.

[0046] S23, after the number of scan lines reaches the maximum number of scan lines in the sub-scanning area, the electron beam is shifted to the first line of the next sub-scanning area of ​​the target to be scanned, and the electron beam is controlled to scan the next sub-scanning area based on the row step voltage value.

[0047] The number of scan lines involved in the embodiment of the present application may refer to the number of lines that the electron beam completes scanning. In one embodiment of the present application, the electron beam scanning control device 11 may use a counter to count the number of scan lines, that is, after the electron beam scans a line, the counter increases by 1. It should be noted that after the number of scan lines reaches the maximum number of scan lines in the sub-scanning area, the number of scan lines starts to accumulate again, that is, the counter is reset. The number of scan lines reaching the maximum number of scan lines in the sub-scanning area can be understood as completing the scan of the first sub-scanning area.

[0048] After scanning the first sub-scanning area, the first row of the next sub-scanning area involved in the embodiment of the present application may be the first row of the second sub-scanning area.

[0049] In one embodiment of the present application, after completing the scanning operation of the first sub-scanning area, the electron beam scanning control device 11 continues to control the movement of the motion platform and controls the electron beam to deflect to the first row of the second sub-scanning area, that is, controls the electron beam to deflect from the last row of the first sub-scanning area to the first row of the second sub-scanning area. And similar to scanning the first sub-scanning area, after the first row of the second sub-scanning area is scanned, the electron beam scanning control device 11 applies a voltage of the row step voltage value to the electron deflector, controls the electron beam to deflect to the second row of the second sub-scanning area to start scanning, that is, the movement of the motion platform is accumulated to control the electron beam to skip N rows and start row scanning from the N+1 row, until the maximum number of scanning rows of the sub-scanning area is scanned, and the electron beam scanning control device 11 determines that the scanning operation of the second sub-scanning area is completed.

[0050] It should be noted that, when the target to be scanned includes 512 rows and N is 1, the last row of the first sub-scanning area may be the 511th row of the target to be scanned, and the first row of the second sub-scanning area may be the 2nd row of the target to be scanned.

[0051] S24, after the number of scan lines reaches the maximum number of scan lines of the sub-scan area, it is determined whether all scan operations of the target to be scanned are completed.

[0052] The scanning line number involved in the embodiment of the present application reaches the maximum scanning line number of the sub-scanning area, which means that the electron beam scanning control device 11 scans the last line of the next sub-scanning area. The entire scanning operation of the target to be scanned may mean scanning the target to be scanned or scanning all sub-scanning areas.

[0053] S25, if all scanning operations of the target to be scanned are not completed, then continue to perform scanning operations of other sub-scanning areas according to the above method until all scanning of the target to be scanned is completed.

[0054] Specifically, when the electron beam scanning control device 11 determines that all scanning operations of the target to be scanned have not been completed, the third sub-area is used as the next sub-scanning area, and the process returns to S23 and S24. Specifically, when the moving platform carrying the target to be scanned is in a moving state, the electron beam is offset to the first row of the third sub-scanning area of ​​the target to be scanned, and the electron beam is controlled to scan the third sub-scanning area based on the row step voltage value. And after the number of scanning rows reaches the maximum number of scanning rows of the sub-scanning area, it is determined whether all scanning operations of the target to be scanned have been completed.

[0055] If it is determined that all scanning operations of the target to be scanned have not been completed, the above scanning operation is repeated to scan the next sub-scanning area. If it is determined that all scanning operations of the target to be scanned have been completed, the scanning operation is stopped.

[0056] In the above embodiment, after obtaining the scanning instruction including the row step voltage value and the maximum number of scanning rows in the sub-scanning area, the electron beam is controlled to scan in the reverse direction of the moving platform from the first sub-scanning area based on the row step voltage value while the moving platform is moving; after the number of scanning rows reaches the maximum number of scanning rows in the sub-scanning area, the electron beam is shifted to the first row of the next sub-scanning area to continue scanning; this process is repeated until all the targets to be scanned are scanned. In this way, the row step voltage value can be adjusted to achieve scanning at intervals of several rows, thereby reducing the occurrence of charging phenomenon during the scanning process, improving the clarity of the scanned image, and enhancing the scanning quality, thereby ensuring the accuracy of defect detection.

[0057] In some embodiments, before S22, when the electron beam scanning control device 11 detects that the moving platform enters the designated scanning area, the electron beam scanning operation is started.

[0058] In some embodiments, in S23, after the number of scanning rows reaches the maximum number of scanning rows of the sub-scanning area, the electron beam is offset to the first row of the next sub-scanning area of ​​the target to be scanned, which may include: obtaining an offset voltage value in the column direction of the electron beam based on the row step voltage value; and using the offset voltage value to offset the electron beam to the first row of the next sub-scanning area of ​​the target to be scanned.

[0059] The offset voltage value of the electron beam column direction involved in the embodiment of the present application may refer to the voltage value required to offset the electron beam from the last row of the previous sub-scanning area of ​​the target to be scanned to the first row of the next sub-scanning area of ​​the target to be scanned.

[0060] In one embodiment, in order to accurately control the offset of the electron beam, the offset voltage value in the electron beam column direction can be determined according to the maximum number of scan lines in the sub-scanning area, the number of sub-scanning areas that have completed scanning, and the row step voltage value. The calculation formula of the offset voltage value in the electron beam column direction can be expressed as:

[0061] U=(-M+1)*step (2)

[0062] Wherein, U represents the offset voltage value, M represents the maximum number of scanning lines in the sub-scanning area, step represents the line step voltage value, and the negative sign of M represents the direction.

[0063] In the above embodiment, after calculating the offset voltage value in the electron beam column direction, the electron beam scanning control device 11 applies a voltage equal to the offset voltage value to the electron deflector so that the electron beam can be accurately offset to the first row of the next sub-scanning area, thereby achieving the purpose of precise offset and realizing efficient and continuous scanning.

[0064] In an example, the relationship between each sub-scanning area and the offset voltage value can be shown in the following table:

[0065]

[0066] In some embodiments, since the sub-scanning area is a scanning area obtained by sampling the target to be scanned every N rows, the target to be scanned may include N+1 sub-scanning areas. Therefore, in S24, judging whether all scanning operations of the target to be scanned are completed may include: judging whether the number of sub-scanning areas that have completed scanning reaches N+1; if it reaches N+1, then it is determined that all scanning operations of the target to be scanned are completed; if it does not reach N+1, then it is determined that all scanning operations of the target to be scanned are not completed.

[0067] In one embodiment of the present application, a counter can be set in the electron beam scanning control device 11 to record the number of sub-scanning areas that have completed scanning. At the beginning of scanning, the electron beam scanning control device 11 clears the counter to 0, and after each sub-scanning area is scanned (the number of scanning lines reaches the maximum number of scanning lines of the sub-scanning area), the counter is increased by 1. After the electron beam scanning control device 11 completes the second sub-scanning area or each subsequent sub-scanning area, it is checked whether the counter reaches N+1. If the counter reaches N+1, it is determined that all scanning operations of the target to be scanned have been completed. If the counter does not reach N+1, it is determined that all scanning operations of the target to be scanned have not been completed.

[0068] In the above embodiment, whether all scanning operations of the target to be scanned are completed is judged by the number of sub-scanning areas that have completed scanning, so that all sub-scanning areas are ensured to be scanned and whether the scanning operation is completed is accurately judged.

[0069] In some embodiments, the electron beam scanning control method may further include: determining the position jitter information of the moving platform based on the real-time position information of the moving platform; determining the jitter compensation voltage value of the electron beam according to the position jitter information; and using the jitter compensation voltage value to perform jitter compensation on the electron beam scanning process.

[0070] The real-time position of the motion platform involved in the embodiment of the present application may be the position information of the motion platform collected in real time by a high-precision sensor (such as a laser ruler, etc.). The position jitter information of the motion platform may refer to the small, non-periodic position deviation of the motion platform on the expected motion trajectory.

[0071] In one embodiment of the present application, the position jitter information of the motion platform can be determined based on the real-time position of the motion platform and the preset position coordinate sequence through a jitter detection algorithm. The position jitter information of the motion platform may include but is not limited to: jitter amplitude, jitter frequency and phase information. The preset position coordinate sequence may refer to the position sequence of the motion platform under the ideal motion state, which can be obtained from the user end or pre-set in the device.

[0072] The jitter compensation voltage value of the electron beam involved in the embodiment of the present application can be used to adjust the output control of the electron beam by the electron beam scanning control device 11, so that the electron beam and the moving platform jitter synchronously to offset the influence of the platform jitter on the electron beam trajectory.

[0073] In one embodiment of the present application, a jitter model of the motion platform can be established according to the position jitter information, and the jitter model can describe the jitter characteristics of the motion platform in detail, and based on the jitter model, the jitter compensation voltage value of the electron beam can be calculated through the compensation algorithm in the control theory (such as forward feedback control, etc.).

[0074] It should be noted that the electron beam scanning control device 11 can calculate the jitter compensation voltage value in real time during the scanning process, or the jitter compensation voltage value is pre-set in the electron beam scanning control device 11 .

[0075] In one embodiment of the present application, when the electron beam scanning control device 11 starts scanning the first sub-scanning area, it applies a jitter compensation voltage value of the size of the electron beam to the electron deflector to achieve real-time jitter compensation for the electron beam scanning process.

[0076] In this way, the jitter compensation voltage value accurately calculated according to the position jitter information can achieve fine-tuning of the electron beam scanning path, ensure the accuracy and consistency of the scanning trajectory, improve scanning accuracy, reduce path deviation and repeated scanning caused by position jitter, and thus improve scanning efficiency. In addition, the jitter compensation mechanism can improve the robustness of the device and maintain the stability and reliability of the device.

[0077] In some embodiments, because an excessively high jitter compensation frequency will introduce additional unstable factors and affect the accuracy of the electron beam scanning path, a jitter compensation voltage value is used to perform jitter compensation on the electron beam scanning process, including: controlling the electron beam to perform jitter compensation during the scanning process according to a preset compensation frequency and the jitter compensation voltage value.

[0078] The preset compensation frequency involved in the embodiment of the present application can be determined according to the jitter characteristics of the motion platform and the performance of the electron beam scanning control device 11. For example, the preset compensation frequency can be set to perform jitter compensation once or multiple times for each scanned line.

[0079] In one embodiment of the present application, the electron beam scanning control device 11 can apply a voltage of a magnitude equal to the jitter compensation voltage value of the electron beam to the electron deflector according to a preset compensation frequency during the scanning process, so as to achieve timing jitter compensation for the electron beam scanning process, thereby further improving the scanning accuracy of the device.

[0080] Another aspect of the embodiments of the present application provides an electron beam scanning control device. Figure 3 A schematic diagram of the structure of an electron beam scanning control device provided in an embodiment of the present application is shown. Figure 3 As shown, the electron beam scanning control device 30 may include the following modules.

[0081] The instruction acquisition module 31 is used to acquire a scanning instruction, wherein the scanning instruction includes: a row step voltage value for controlling a scanning offset in the electron beam column direction and a maximum number of scanning rows in a sub-scanning area.

[0082] The scanning module 32 is used to control the electron beam to start scanning from the first sub-scanning area of ​​the target to be scanned based on the row step voltage value when the moving platform carrying the target to be scanned is in a moving state; the sub-scanning area is a scanning area obtained by sampling the target to be scanned every N rows, where N is an integer greater than or equal to 1, and the moving direction of the moving platform is opposite to the column direction when the electron beam scans.

[0083] The offset control module 33 is used to offset the electron beam to the first row of the next sub-scanning area of ​​the target to be scanned after the number of scanning rows reaches the maximum number of scanning rows of the sub-scanning area, so that the scanning module controls the electron beam to scan the next sub-scanning area based on the row step voltage value.

[0084] The judgment module 34 is used to judge whether all scanning operations of the target to be scanned are completed after the number of scanning lines reaches the maximum number of scanning lines of the sub-scanning area.

[0085] The offset control module 33 and the scanning module 34 are also used to continue to perform scanning operations on other sub-scanning areas when all scanning operations on the target to be scanned are not completed, until all scanning operations on the target to be scanned are completed.

[0086] In the above embodiment, after obtaining the scanning instruction including the row step voltage value and the maximum number of scanning rows in the sub-scanning area, the electron beam is controlled to scan in the reverse direction of the moving platform from the first sub-scanning area based on the row step voltage value while the moving platform is moving; after the number of scanning rows reaches the maximum number of scanning rows in the sub-scanning area, the electron beam is shifted to the first row of the next sub-scanning area to continue scanning; this process is repeated until all the targets to be scanned are scanned. In this way, the row step voltage value can be adjusted to achieve scanning at intervals of several rows, thereby reducing the occurrence of charging phenomenon during the scanning process, improving the clarity of the scanned image, and enhancing the scanning quality, thereby ensuring the accuracy of defect detection.

[0087] In addition, the present application combines the movement of the motion platform so that the scanning of the electron beam in the column direction is opposite to the movement direction of the motion platform, thereby further improving the scanning speed through the combined motion mode, thereby improving the overall scanning efficiency.

[0088] In some embodiments, the offset control module 33 is further used to obtain an offset voltage value in the column direction of the electron beam based on the row step voltage value; and use the offset voltage value to offset the electron beam to the first row of the next sub-scanning area of ​​the target to be scanned.

[0089] In some embodiments, obtaining the offset voltage value in the electron beam column direction based on the row step voltage value includes: obtaining the offset voltage value using the following formula;

[0090] U = (-M + 1) * step;

[0091] Wherein, U represents the offset voltage value, M represents the maximum number of scanning lines in the sub-scanning area, and step represents the line step voltage value.

[0092] In some embodiments, the judgment module 34 is specifically used to determine whether the number of sub-scanning areas that have completed scanning has reached N+1; if it has reached N+1, it is determined that all scanning operations of the target to be scanned have been completed; if it has not reached N+1, it is determined that all scanning operations of the target to be scanned have not been completed.

[0093] In some embodiments, the electron beam scanning control device may further include the following modules.

[0094] The jitter information determination module is used to determine the position jitter information of the motion platform based on the real-time position information of the motion platform.

[0095] A compensation voltage value determination module, used for determining a jitter compensation voltage value of the electron beam according to the position jitter information;

[0096] The jitter compensation module is used to perform jitter compensation on the electron beam scanning process by using the jitter compensation voltage value.

[0097] In some embodiments, the jitter compensation module is specifically used to control the electron beam to perform jitter compensation during the scanning process according to the jitter compensation voltage value at a preset compensation frequency.

[0098] It should be understood that the specific features, operations and details described hereinabove with respect to the method of the present application may also be similarly applied to the device and system of the present application, or vice versa. In addition, each step of the method of the present application described above may be performed by a corresponding component or unit of the device or system of the present application.

[0099] It should be understood that each module / unit of the device of the present application can be implemented in whole or in part by software, hardware, firmware or a combination thereof. Each module / unit can be embedded in the processor of the electronic device or independent of the processor in the form of hardware or firmware, or can be stored in the memory of the electronic device in the form of software for the processor to call to perform the operation of each module / unit. Each module / unit can be implemented as an independent component or module, or two or more modules / units can be implemented as a single component or module.

[0100] The present application provides a computer-readable storage medium. Figure 4 A schematic diagram showing the structure of a computer-readable storage medium provided in an embodiment of the present application is shown as follows: Figure 4 As shown, a computer-readable storage medium 40 stores a computer-executable program 41 , wherein when the computer-executable program is executed by a processor, the steps of the electron beam scanning control method provided in any embodiment of the present application are implemented.

[0101] The present application provides a computer program product, Figure 5 A schematic diagram showing the structure of a computer-readable storage medium provided in an embodiment of the present application is shown as follows: Figure 5 As shown, the computer program product 50 includes computer executable instructions 51, wherein when the computer executable instructions are executed by a processor, the steps of the electron beam scanning control method provided in any embodiment of the present application are implemented.

[0102] Those skilled in the art will appreciate that the method steps of the present application can be completed by instructing related hardware such as electronic devices or processors through a computer program, and the computer program can be stored in a non-temporary computer-readable storage medium, and the computer program causes the steps of the present application to be executed when it is executed. Depending on the circumstances, any reference to memory, storage or other media herein may include non-volatile or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0103] The various technical features described above can be combined arbitrarily. Although all possible combinations of these technical features are not described, any combination of these technical features should be considered to be covered by this specification as long as there is no contradiction in such combination.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electron beam scanning control method, characterized in that: include: Obtaining a scanning instruction, wherein the scanning instruction includes: a row step voltage value for controlling a scanning offset in a column direction of an electron beam and a maximum number of scanning rows in a sub-scanning area; When the moving platform carrying the target to be scanned is in a moving state, the electron beam is controlled to start scanning from the first sub-scanning area of ​​the target to be scanned based on the row step voltage value; the sub-scanning area is a scanning area obtained by sampling the target to be scanned at intervals of N rows, N is an integer greater than or equal to 1, and the moving direction of the moving platform is opposite to the column direction when the electron beam is scanning; After the number of scan lines reaches the maximum number of scan lines of the sub-scanning area, the electron beam is shifted to the first line of the next sub-scanning area of ​​the target to be scanned, and the electron beam is controlled to scan the next sub-scanning area based on the row step voltage value; After the number of scan lines reaches the maximum number of scan lines in the sub-scanning area, determining whether all scan operations of the target to be scanned are completed; If the scanning operation of the target to be scanned is not completed, the scanning operation of other sub-scanning areas is continued to be performed according to the above method until the scanning of the target to be scanned is completed.

2. The method according to claim 1, characterized in that After the number of scanning lines reaches the maximum number of scanning lines in the sub-scanning area, the electron beam is shifted to the first line of the next sub-scanning area of ​​the target to be scanned, comprising: Obtaining an offset voltage value in the electron beam column direction based on the row step voltage value; The electron beam is offset to the first row of the next sub-scanning area of ​​the object to be scanned by using the offset voltage value.

3. The method according to claim 2, characterized in that The step of obtaining the offset voltage value of the electron beam column direction based on the row step voltage value comprises: obtaining the offset voltage value using the following formula; U = (-M + 1) * step; Wherein, U represents the offset voltage value, M represents the maximum number of scanning lines in the sub-scanning area, and step represents the line step voltage value.

4. The method according to claim 1, characterized in that: The determining whether all scanning operations of the target to be scanned are completed includes: Determine whether the number of sub-scanning areas that have completed scanning has reached N+1; If the number reaches N+1, it is determined that all scanning operations of the target to be scanned are completed.

5. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: Determine the position jitter information of the motion platform based on the real-time position information of the motion platform; Determine a jitter compensation voltage value of the electron beam according to the position jitter information; The jitter compensation voltage value is used to perform jitter compensation on the electron beam scanning process.

6. The method according to claim 5, characterized in that The step of using the jitter compensation voltage value to perform jitter compensation on the electron beam scanning process includes: According to the preset compensation frequency and the jitter compensation voltage value, the electron beam is controlled to perform jitter compensation during scanning.

7. An electron beam scanning control device, characterized in that: include: An instruction acquisition module is used to acquire a scanning instruction, wherein the scanning instruction includes: a row step voltage value for controlling a scanning offset in the electron beam column direction and a maximum number of scanning rows in a sub-scanning area; A scanning module, used for controlling the electron beam to scan from the first sub-scanning area of ​​the target to be scanned based on the row step voltage value when the motion platform carrying the target to be scanned is in a moving state; the sub-scanning area is a scanning area obtained by sampling the target to be scanned every N rows, wherein N is an integer greater than or equal to 1, and the moving direction of the motion platform is opposite to the column direction when the electron beam is scanning; an offset control module, for offsetting the electron beam to the first row of the next sub-scanning area of ​​the target to be scanned after the number of scanned rows reaches the maximum number of scanned rows of the sub-scanning area, so that the scanning module controls the electron beam to scan the next sub-scanning area based on the row step voltage value; A judgment module, used for judging whether all scanning operations of the target to be scanned are completed after the number of scanning lines reaches the maximum number of scanning lines of the sub-scanning area; The offset control module and the scanning module are further used to continue to perform scanning operations in other sub-scanning areas when all scanning operations of the target to be scanned are not completed, until all scanning of the target to be scanned is completed.

8. A scanning electron microscope, characterized in that include: The electron beam scanning control device as claimed in claim 7.

9. A computer program product, characterized in that The computer program product comprises computer executable instructions, wherein when the computer executable instructions are executed by a processor, the steps of the electron beam scanning control method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer-executable program, wherein when the computer-executable program is executed by a processor, the steps of the electron beam scanning control method according to any one of claims 1 to 6 are implemented.

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