Charged particle beam scanning aberration correction method and system

Abstract

The present application relates to a charged particle beam scanning aberration correction method and system thereof. The method comprises: determining a reference deflector and a deflector to be calibrated; obtaining a first scanning image of the reference deflector and a second scanning image of the deflector to be calibrated respectively; determining a first scanning deflection angle of the reference deflector according to the first scanning image, determining a second scanning deflection angle of the deflector to be calibrated according to the second scanning image, and determining a scanning deflection angle difference according to the difference between the two; obtaining a design angle difference between the reference deflector and the deflector to be calibrated; determining a mechanical deviation angle according to the difference between the scanning deflection angle difference and the design angle difference; determining an imaging compensation angle according to the mechanical deviation angle, outputting a target scanning waveform based on the imaging parameters of a graphic generator adjusted according to the imaging compensation angle; and correcting the scanning signal according to the target scanning waveform. The present application can correct the scanning aberration of a charged particle beam scanning imaging system, thereby improving the imaging quality.

Description

Technical Field

[0001] The present application relates to the technical field of charged particle beam scanning imaging, and in particular to a charged particle beam scanning aberration correction method and system thereof. Background Art

[0002] In the field of charged particle beam scanning imaging technology, in order to enable the charged particle beam to perform controllable and regular raster scanning on the sample surface, the charged particle beam scanning imaging system designs a scanning deflector on the charged particle beam path to realize scanning fields in different scanning directions; in order to achieve a larger scanning field and reduce scanning aberrations, the charged particle beam scanning imaging system generally includes two or more groups of multi-channel scanning deflectors, which are arranged in sequence along the moving direction of the charged particle beam. The charged particle beam scanning imaging system generates scanning electric fields or scanning magnetic fields with different scanning angles and scanning amplitudes through the scanning deflector and the scanning waveform generator that drives the scanning deflector, so that the charged particle beam can be sequentially scanned point by point and line by line on the sample surface.

[0003] In the related technologies, charged particle beam scanning imaging systems have been widely used in scientific research and semiconductor manufacturing fields, and are important detection equipment for studying the surface microstructure of various materials, semiconductor device defect detection, and graphic measurement. However, with the continuous advancement of semiconductor technology, semiconductor devices are gradually miniaturized, and charged particle beam scanning imaging systems need to further improve imaging resolution to meet related detection needs. Summary of the invention

[0004] Based on this, the embodiments of the present application provide a charged particle beam scanning aberration correction method and system thereof, which can accurately correct the scanning signal of the scanning deflector, thereby effectively reducing the scanning aberration and effectively improving the scanning imaging quality of the charged particle beam scanning imaging system.

[0005] In order to achieve the above-mentioned object, on the one hand, some embodiments of the present application provide a charged particle beam scanning aberration correction method. The charged particle beam scanning aberration correction method is used to correct the scanning aberration of a charged particle beam scanning imaging system. The charged particle beam scanning system includes a multi-channel scanning deflector arranged in sequence along the moving direction of the charged particle beam and a multi-channel scanning waveform generator respectively connected to each channel scanning deflector. The charged particle beam scanning aberration correction method includes the following steps.

[0006] A reference deflector and a deflector to be calibrated are determined from the multi-channel scanning deflectors.

[0007] A first scanning image of a reference deflector with respect to a characteristic pattern and a second scanning image of a deflector to be calibrated with respect to the same characteristic pattern are acquired respectively.

[0008] A first scanning deflection angle of a reference deflector is determined according to the first scanning image, a second scanning deflection angle of the deflector to be calibrated is determined according to the second scanning image, and a scanning deflection angle difference is determined according to the difference between the first scanning deflection angle and the second scanning deflection angle.

[0009] Obtain the design angle difference of the installation angle between the reference deflector and the deflector to be calibrated.

[0010] The mechanical deviation angle is determined based on the difference between the scan deflection angle difference and the design angle difference.

[0011] The imaging compensation angle of the pattern generator is determined according to the mechanical deviation angle, so as to adjust the imaging parameters of the pattern generator according to the imaging compensation angle, and enable the scanning waveform generator to output the target scanning waveform according to the adjusted imaging parameters.

[0012] The scanning signal of the deflector to be calibrated during scanning imaging is corrected according to the target scanning waveform.

[0013] In some embodiments, the deflector to be calibrated includes at least two channel scanning deflectors; wherein, the second scanning image of the characteristic pattern of each channel scanning deflector in the deflector to be calibrated is obtained by scanning the characteristic pattern by the channel scanning deflector alone; and the target scanning waveform of each channel scanning deflector in the deflector to be calibrated is determined based on the mechanical deviation angle corresponding to the channel scanning deflector.

[0014] In some embodiments, the first scan image of the reference deflector and the second scan image of the deflector to be calibrated are obtained by scanning the same characteristic pattern under the same imaging conditions.

[0015] In some embodiments, determining a reference deflector and a deflector to be calibrated from a multi-channel scanning deflector includes the following steps.

[0016] The first channel scanning deflector arranged in sequence along the moving direction of the charged particle beam is taken as the initial reference deflector, and the second channel and subsequent channel scanning deflectors are the deflectors to be calibrated.

[0017] Obtain a scanning verification image of the initial reference deflector against the target reference pattern.

[0018] Determine whether the focusing center of the scanning verification image is located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system; in response to the focusing center of the scanning verification image being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, determine that the initial reference deflector is the reference deflector; and in response to the focusing center of the scanning verification image not being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, adjust the sampling window parameters corresponding to the scanning verification image until the focusing center of the scanning verification image is adjusted to the geometric center of the imaging area of ​​the charged particle beam scanning imaging system and the initial reference deflector is determined to be the reference deflector.

[0019] In some embodiments, each channel scanning deflector includes a first deflection electrode and a second deflection electrode. The target scanning waveform includes a row scanning signal and a frame scanning signal. The scanning signal of the deflector to be calibrated during scanning imaging is corrected according to the target scanning waveform, including: determining a first scanning signal when the first deflection electrode is scanning imaging and a second scanning signal when the second deflection electrode is scanning imaging according to the row scanning signal, the frame scanning signal and the mechanical deviation angle.

[0020] In some embodiments, the charged particle beam scanning aberration correction method further includes: when the imaging condition of the charged particle beam scanning imaging system changes, determining the scanning deviation angle of the deflector to be calibrated according to the changed imaging condition.

[0021] Correspondingly, the imaging compensation angle of the graphic generator is determined according to the mechanical deviation angle, so as to adjust the imaging parameters of the graphic generator according to the imaging compensation angle, and the scanning waveform generator outputs the target scanning waveform according to the adjusted imaging parameters, including: determining the imaging compensation angle of the graphic generator according to the mechanical deviation angle and the scanning deviation angle, so as to adjust the imaging parameters of the graphic generator according to the imaging compensation angle, and the scanning waveform generator outputs the target scanning waveform according to the adjusted imaging parameters.

[0022] In some embodiments, the imaging condition includes the landing energy of the charged particle beam. When the imaging condition of the charged particle beam scanning imaging system changes, the scanning deviation angle of the deflector to be calibrated is determined according to the changed imaging condition, including: when the imaging condition of the charged particle beam scanning imaging system changes, the landing energy change amount of the charged particle beam is obtained, and the scanning deviation angle of the deflector to be calibrated is determined according to the landing energy change amount.

[0023] In some examples, an imaging compensation angle of a graphic generator is determined according to a mechanical deviation angle and a scanning deviation angle to adjust imaging parameters of the graphic generator according to the imaging compensation angle, and a scanning waveform generator is caused to output a target scanning waveform according to the adjusted imaging parameters, including: determining a first imaging compensation angle of the graphic generator according to the mechanical deviation angle to adjust the imaging parameters of the graphic generator for a first time according to the first imaging compensation angle, and causing the scanning waveform generator to output a first target scanning waveform according to the imaging parameters adjusted for the first time; determining a second imaging compensation angle of the graphic generator according to a scanning deviation angle caused by a change in landing energy of a charged particle beam, to adjust the imaging parameters of the graphic generator for a second time according to the second imaging compensation angle, and causing the scanning waveform generator to output a second target scanning waveform according to the imaging parameters adjusted for the second time.

[0024] Alternatively, in other examples, an imaging compensation angle of the graphic generator is determined based on the mechanical deviation angle and the scanning deviation angle, so as to adjust the imaging parameters of the graphic generator based on the imaging compensation angle, and enable the scanning waveform generator to output a target scanning waveform based on the adjusted imaging parameters. The method also includes: determining a total deviation angle based on the mechanical deviation angle and the scanning deviation angle caused by the change in landing energy of the charged particle beam, determining a third imaging compensation angle of the graphic generator based on the total deviation angle, so as to adjust the imaging parameters of the graphic generator based on the third imaging compensation angle, and enable the scanning waveform generator to output a third target scanning waveform based on the adjusted imaging parameters.

[0025] On the other hand, the present application also provides a charged particle beam scanning aberration correction system according to some embodiments. The charged particle beam scanning aberration correction system is used to perform the steps of the charged particle beam scanning aberration correction method as described in some of the aforementioned embodiments of the present application to correct the scanning aberration of the charged particle beam scanning imaging system. The charged particle beam scanning imaging system includes a multi-channel scanning deflector arranged in sequence along the direction of movement of the charged particle beam and a multi-channel scanning waveform generator respectively connected to each channel scanning deflector. The multi-channel scanning deflector includes a reference deflector and a deflector to be calibrated. The charged particle beam scanning aberration correction system includes an image acquisition module, an image processing module, a data processing module and a scanning control module. The image acquisition module includes a graphic generator and an image collector.

[0026] The image collector is configured to respectively acquire a first scanning image of a reference deflector pair of characteristic patterns and a second scanning image of a deflector to be calibrated pair of the same characteristic patterns.

[0027] The image processing module is connected to the image collector and is configured to: determine a first scanning deflection angle of the reference deflector according to the first scanning image, and determine a second scanning deflection angle of the deflector to be calibrated according to the second scanning image.

[0028] The data processing module is connected to the image processing module and the pattern generator. The data processing module is configured to: determine the scanning deflection angle difference according to the difference between the first scanning deflection angle and the second scanning deflection angle; obtain the design angle difference of the installation angle between the reference deflector and the deflector to be calibrated; determine the mechanical deviation angle according to the difference between the scanning deflection angle difference and the design angle difference; and determine the imaging compensation angle of the pattern generator according to the mechanical deviation angle.

[0029] The scanning control module is connected to the pattern generator and the data processing module. The scanning control module is configured to: adjust the imaging parameters of the pattern generator according to the imaging compensation angle, and make the scanning waveform generator output the target scanning waveform according to the adjusted imaging parameters; and correct the scanning signal of the deflector to be calibrated when scanning imaging according to the target scanning waveform.

[0030] In some embodiments, the charged particle beam scanning aberration correction system further includes a reference deflector determination module. Wherein, the image collector is further configured to: before acquiring the first scanning image of the reference deflector to the characteristic pattern, take the first channel scanning deflector arranged in sequence along the movement direction of the charged particle beam as the initial reference deflector, and acquire the scanning verification image of the initial reference deflector to the target reference pattern. The reference deflector determination module is connected to the image collector and the scanning control module. The reference deflector determination module is configured to: determine whether the focus center of the scanning verification image is located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, in response to the focus center of the scanning verification image being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, determine the initial reference deflector as the reference deflector; and in response to the focus center of the scanning verification image not being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, adjust the sampling window parameters of the image collector until the focus center of the scanning verification image is adjusted to the geometric center of the imaging area of ​​the charged particle beam scanning imaging system and determine the initial reference deflector as the reference deflector.

[0031] In some embodiments, the imaging condition of the charged particle beam scanning imaging system includes the landing energy of the charged particle beam. The data processing module is further configured to: when the imaging condition of the charged particle beam scanning imaging system changes, obtain the landing energy change of the charged particle beam, determine the scanning deviation angle according to the landing energy change; and determine the imaging compensation angle of the pattern generator according to the mechanical deviation angle and the scanning deviation angle.

[0032] The embodiment of the present application may / at least have the following advantages: In the embodiment of the present application, by obtaining the scanning deflection angle difference between the first scanning image of the reference deflector and the second scanning image of the deflector to be calibrated, and the design angle difference of the installation angle between the reference deflector and the deflector to be calibrated, and determining the mechanical deviation angle according to the difference between the scanning deflection angle difference and the design angle difference, the imaging compensation angle of the pattern generator is determined according to the mechanical deviation angle. In this way, the embodiment of the present application determines the mechanical deviation angle based on the scanning deflection angle difference obtained by actual scanning and the design angle difference obtained by theoretical calculation, that is, the angle compensation amount required to correct the mechanical installation error is determined; and the imaging compensation angle of the pattern generator is determined according to the mechanical deviation angle, and the scanning waveform generator outputs the target scanning waveform based on the imaging parameters adjusted by the pattern generator according to the imaging compensation angle, so as to correct the scanning signal of the deflector to be calibrated according to the target scanning waveform, so as to compensate for the mechanical installation error; the accurate correction of the mechanical installation error in the multi-channel scanning deflector is realized, and the scanning aberration of the charged particle beam scanning imaging system is effectively reduced, thereby improving the imaging quality.

[0033] The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic diagram of the structure of a charged particle beam scanning imaging system provided in some embodiments.

[0036] Figure 2 A schematic diagram of the structure of another charged particle beam scanning imaging system provided in some embodiments.

[0037] Figure 3 is a waveform diagram of a target scanning waveform provided in some embodiments; wherein, Figure 3 Figure (a) is a waveform diagram of a row scanning signal provided in some embodiments. Figure 3 Figure (b) is a waveform diagram of a frame scanning signal provided in some embodiments.

[0038] Figure 4 A schematic diagram of a scanning method of a charged particle beam scanning imaging system provided in some embodiments.

[0039] Figure 5 A schematic flow chart of a charged particle beam scanning aberration correction method provided in some embodiments.

[0040] Figure 6 A flowchart of step S100 provided in some embodiments.

[0041] Figure 7 This is a flowchart of another step S100 provided in some embodiments.

[0042] Figure 8 A schematic flow chart of another charged particle beam scanning aberration correction method provided in some embodiments.

[0043] Fig. 9 The present invention is a schematic flow chart of another charged particle beam scanning aberration correction method provided in some embodiments.

[0044] Fig.10 The present invention is a schematic flow chart of another charged particle beam scanning aberration correction method provided in some embodiments.

[0045] Fig.11 The present invention is a schematic flow chart of another charged particle beam scanning aberration correction method provided in some embodiments.

[0046] Fig.12 A schematic diagram of the positional relationship between a scanning verification image and an imaging area provided in some embodiments.

[0047] Fig.13 is a schematic diagram of a first scan image and a second scan image provided in some embodiments; wherein, Fig.13 Figure (a) is a schematic diagram of a first scan image provided in some embodiments. Fig.13 FIG. (b) is a schematic diagram of a first scanning sub-image of a first deflector to be calibrated provided in some embodiments. Fig.13 Figure (c) is a schematic diagram of a second scanning sub-image of a second deflector to be calibrated provided in some embodiments.

[0048] Fig.14 Schematic diagram of the design angle of the multi-channel scanning deflector provided in some embodiments; wherein, Fig.14 Figure (a) is a schematic diagram of the design angle of a reference deflector provided in some embodiments. Fig.14 Figure (b) is a schematic diagram of the design angle of a first deflector to be calibrated provided in some embodiments, Fig.14 Figure (c) is a schematic diagram of the design angle of a second deflector to be calibrated provided in some embodiments.

[0049] Fig.15 A schematic diagram of the positions of a first deflection electrode and a second deflection electrode provided in some embodiments.

[0050] Fig.16 It is a structural block diagram of a charged particle beam scanning aberration correction system provided in some embodiments.

[0051] Fig.17 It is a structural block diagram of another charged particle beam scanning aberration correction system provided in some embodiments.

[0052] Explanation of the accompanying drawings: 1-electron optical lens barrel, 11-electron source, 12-focusing lens, 13-aperture, T-detector module, D1-preamplifier, D2-main amplifier, 2-multi-channel scanning deflector, 21-first deflection electrode, 22-second deflection electrode, S-multi-channel scanning waveform generator, A-scan verification image, E-imaging area, B-first scanning image, C1-first scanning sub-image, C2-second scanning sub-image, 3-image acquisition module, 31-graphic generator, 32-image collector, 4-image processing module, 5-data processing module, 6-scanning control module, 7-reference deflector determination module. DETAILED DESCRIPTION

[0053] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0055] It should be understood that when an element or layer is referred to as being "on," "adjacent to," or "connected to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types, and / or portions, these elements, components, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, doping type, or portion from another element, component, region, layer, doping type, or portion. Therefore, without departing from the teachings of the present application, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion.

[0056] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that when the terms "consisting of" and / or "comprising" are used in this specification, the presence of the features, integers, steps, operations, elements and / or parts can be determined, but the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups is not excluded. At the same time, when used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0057] Embodiments of the invention are described herein with reference to cross-sectional views that are schematic representations of idealized embodiments (and intermediate structures) of the present application, such that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances are anticipated. Embodiments of the present application should not be limited to the specific shapes of the regions shown herein, but include deviations in shapes due to, for example, manufacturing techniques. Therefore, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shapes of the regions of the device, and do not limit the scope of the present application.

[0058] In the field of scanning imaging technology, in order to enable the charged particle beam to perform a controllable and regular raster scan on the sample surface, the charged particle beam scanning imaging system designs a multi-channel scanning deflector (i.e., a multi-channel scanning deflector) on the motion path of the charged particle beam to realize different scanning fields; taking the two-channel scanning deflector as an example, the first channel scanning deflector in the motion direction of the charged particle beam will deflect the charged particle beam off-axis, and the second channel scanning deflector will deflect the charged particle beam back to the optical axis, so that the charged particle beam can be scanned point by point and line by line on the sample surface in sequence. In the current charged particle beam scanning imaging system, the multi-channel scanning deflector needs to be based on its electric field distribution and / or magnetic field distribution, and the angle relationship and proportional relationship between the scanning deflectors at each level are determined by simulation calculation, in order to achieve the minimum scanning aberration according to the theoretical simulation optimization design. Under specific imaging conditions, the angle relationship between the deflectors can be realized by the mechanical installation position. Among them, taking the two-channel scanning deflector as an example, the output voltage or output current between the first channel scanning deflector and the second channel scanning deflector has a certain ratio and angle relationship. The total scanning waveform outputted after each channel scanning deflector in the multi-channel scanning deflector works and scans simultaneously is synthesized by the scanning waveforms of each channel deflector.

[0059] However, in the actual installation process of the multi-channel scanning deflector, there will inevitably be a certain deviation between the actual mechanical installation angle and the designed installation angle (that is, there is a mechanical installation error), and the relative deviation angle between different scanning deflectors is difficult to obtain through mechanical measurement, and this mechanical installation error is difficult to effectively improve through mechanical adjustment; this will cause a large scanning aberration in the charged particle beam scanning imaging system, thereby reducing the imaging quality of the charged particle beam scanning imaging system.

[0060] In response to the above problems, an embodiment of the present application provides a charged particle beam scanning aberration correction method and system, which can accurately correct the scanning signal of the scanning deflector, thereby effectively reducing the scanning aberration and effectively improving the scanning imaging quality of the charged particle beam scanning imaging system.

[0061] Please note that Figure 1 and Figure 2 The charged particle beam scanning imaging system includes an electron optical lens barrel 1, a detector module T, a multi-channel scanning deflector 2, a multi-channel scanning waveform generator S, an image collector and a graphic generator 31.

[0062] For example, the electron optical lens barrel 1 includes an electron source 11, a charged particle beam accelerating structure, at least one focusing lens 12, at least one aperture 13 and an anti-stigmation device, etc.; the electron source 11 is used to generate a charged particle beam after being heated to a certain temperature and a certain electric field strength is applied; the charged particle beam accelerating structure is used to accelerate the charged particle beam; the focusing lens 12 is used to focus the accelerated charged particle beam on the surface of the scanned sample; the aperture 13 is used to shield off-axis stray electrons and constrain or adjust the beam half angle; the anti-stigmation device is used to perform preliminary aberration correction on the charged particle beam.

[0063] In some examples, the detector module T includes a semiconductor detector with a through hole in the center; in other examples, the detector module T includes a scintillator and multiplier tube type electronic detector (i.e., a scintillator detector). It should be noted that the semiconductor detector needs to be connected to an amplifier, and the amplifier provides a signal to the analog-to-digital converter, thereby converting the electronic current collected by the semiconductor detector into a digital signal; the scintillator detector converts the electronic signal into an electrical signal and an optical signal, and finally the photomultiplier tube outputs a voltage signal or a current signal, and then provides a signal to the analog-to-digital signal converter, thereby converting the electrical signal collected by the scintillator detector into a digital signal.

[0064] By way of example, the detector module T is located at a position on the moving trajectory of the charged particle beam that is easy to receive electrical signals.

[0065] For example, the detector module T is used to detect changes in the amplitude of the signal electron current emitted by the scanning sample during the scanning process of the charged particle beam scanning imaging system; when the charged particle beam scans the scanning sample, the detector module T can analyze the changes in the amplitude of the electron signal current caused by changes in the composition and morphology of the sample.

[0066] For some examples, see Figure 2 The detector module T is connected to the pattern generator 31 via the preamplifier D1 and the main amplifier D2 in sequence; the detector module T is also used to feed back the change of the amplitude of the signal electron current emitted by the scanned sample to the pattern generator 31.

[0067] For some examples, see Figure 1 and Figure 2 The multi-channel scanning deflector 2 includes scanning deflectors of multiple channels arranged in sequence along the moving direction of the charged particle beam.

[0068] It should be noted that the scanning deflector can be an electrostatic deflector or a magnetic deflector, and this application does not impose any limitation on this.

[0069] By way of example, each channel scanning deflector may be a two-channel field device coaxial with the optical axis of the charged particle beam and distributed radially along the optical axis.

[0070] For some examples, see Figure 2 The multi-channel scanning waveform generator S includes scanning waveform generators of multiple channels respectively connected to the scanning deflectors of each channel; wherein each channel scanning waveform generator is controlled by a graphic generator 31, and the scanning waveform generator can output the scanning waveform of each channel scanning deflector separately or synthesize the scanning waveforms of multiple channel deflectors and output them.

[0071] For example, the scanning waveform generator can be used for electrostatic scanning deflection or magnetic scanning deflection; the scanning waveform generator is limited to the type of the scanning deflector, and the present application does not impose any restrictions on this.

[0072] By way of example, the multi-channel scanning waveform generator is used to send a time-varying scanning waveform to the multi-channel scanning deflector 2 to control the scanning signal that drives the multi-channel scanning deflector 2 .

[0073] Illustratively, the scan signal includes a voltage signal and / or a current signal.

[0074] For example, the multi-channel scanning deflector 2 is used to generate a scanning signal according to the scanning waveform output by the multi-channel scanning waveform generator, and generate a corresponding alternating electric field (or magnetic field) to change the motion trajectory of the charged particle beam.

[0075] It should be noted that when the charged particle beam scanning imaging system performs scanning imaging, the specific scanning implementation method can be: sending an imaging parameter determination instruction to the pattern generator 31, the pattern generator 31 determines the imaging parameters, and then the multi-channel scanning waveform generator S generates a corresponding scanning waveform according to the imaging parameters to control the multi-channel deflector to generate a scanning electric field or a scanning magnetic field with opposite polarities of the electrode pairs; wherein the scanning waveform includes a row scanning signal V L and frame scan signal V F , row scanning signal V L and frame scan signal V F Used to control the scanning electric field or scanning magnetic field output by the scanning deflector; the line scanning signal V L and frame scan signal V F The specific waveform can be, for example, Figure 3 The scanning waveform controls the scanning deflectors of each channel to work synchronously, and drives the charged particle beam to scan and deflect in the first direction (e.g., X direction) and the second direction (e.g., Y direction) at a constant rate, forming a series of roughly parallel scanning lines (e.g., Figure 4 As shown in the figure, the charged particle beam is scanned point by point and line by line on the sample surface in sequence.

[0076] In some embodiments, a charged particle beam scanning aberration correction method is used to correct the scanning aberration of a charged particle beam scanning imaging system. Figure 5 The charged particle beam scanning aberration correction method includes the following steps S100~S700.

[0077] S100, determining a reference deflector and a deflector to be calibrated from the multi-channel scanning deflectors.

[0078] S200, respectively acquiring a first scanning image of a reference deflector with respect to a characteristic pattern and a second scanning image of a deflector to be calibrated with respect to the same characteristic pattern.

[0079] It should be noted that the scanning deflection angle of each channel scanning deflector in the charged particle beam scanning imaging system is independently adjustable.

[0080] In some embodiments, the first scan image of the reference deflector and the second scan image of the deflector to be calibrated are obtained for the same feature pattern under the same imaging conditions.

[0081] S300, determining a first scanning deflection angle of a reference deflector according to a first scanning image, determining a second scanning deflection angle of a deflector to be calibrated according to a second scanning image, and determining a scanning deflection angle difference according to a difference between the first scanning deflection angle and the second scanning deflection angle.

[0082] S400: Obtain a design angle difference between the installation angles of a reference deflector and a deflector to be calibrated.

[0083] S500, determining a mechanical deviation angle according to a difference between a scanning deflection angle difference and a design angle difference.

[0084] S600, determining an imaging compensation angle of a pattern generator according to a mechanical deviation angle, adjusting imaging parameters of the pattern generator according to the imaging compensation angle, and causing a scanning waveform generator to output a target scanning waveform according to the adjusted imaging parameters.

[0085] S700, correcting the scanning signal of the deflector to be calibrated when scanning and imaging according to the target scanning waveform.

[0086] It is worth mentioning that, in some embodiments, the deflector to be calibrated includes at least two channel scanning deflectors; wherein, in step S200, the second scanning image of the characteristic pattern of each channel scanning deflector in the deflector to be calibrated is obtained by scanning the characteristic pattern by the channel scanning deflector alone; and in step S600, the target scanning waveform of each channel scanning deflector in the deflector to be calibrated is determined based on the mechanical deviation angle corresponding to the channel scanning deflector.

[0087] In the embodiment of the present application, the scanning deflection angle difference between the first scanning image of the reference deflector and the second scanning image of the deflector to be calibrated, as well as the design angle difference of the installation angle between the reference deflector and the deflector to be calibrated are obtained, and the mechanical deviation angle is determined according to the difference between the scanning deflection angle difference and the design angle difference, so as to determine the imaging compensation angle of the graphic generator according to the mechanical deviation angle. In this way, the embodiment of the present application determines the mechanical deviation angle based on the scanning deflection angle difference obtained by actual scanning and the design angle difference obtained by theoretical calculation, that is, determines the angle compensation amount required to correct the mechanical installation error; and determines the imaging compensation angle of the graphic generator according to the mechanical deviation angle, and outputs the target scanning waveform through the scanning waveform generator based on the imaging parameters adjusted by the graphic generator according to the imaging compensation angle, so as to correct the scanning signal of the deflector to be calibrated according to the target scanning waveform, so as to compensate for the mechanical installation error; and realizes the accurate correction of the mechanical installation error in the multi-channel scanning deflector, effectively reduces the scanning aberration of the charged particle beam scanning imaging system, and thus improves the imaging quality.

[0088] In some embodiments, see Figure 6 In step S100, determining the reference deflector and the deflector to be calibrated from the multi-channel scanning deflector may include the following steps S110~S130.

[0089] S110, taking the first channel scanning deflector arranged in sequence along the moving direction of the charged particle beam as the initial reference deflector, and the second channel and subsequent channel scanning deflectors as the deflectors to be calibrated.

[0090] It should be noted here that the deflector to be calibrated may be one or more of the scanning deflectors of the second channel and other subsequent channels, and the present disclosure does not impose any limitation on this.

[0091] S120, obtaining a scanning verification image of the target reference pattern by the initial reference deflector.

[0092] Here, it should be noted that the target reference pattern and the characteristic pattern can be the same pattern or different patterns, and the present disclosure does not limit this.

[0093] S130, determining whether the focusing center of the scanning verification image is located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system; in response to the focusing center of the scanning verification image being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, determining that the initial reference deflector is the reference deflector; and in response to the focusing center of the scanning verification image not being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, adjusting the sampling window parameters corresponding to the scanning verification image (i.e., the sampling window parameters of the image collector) until the focusing center of the scanning verification image is adjusted to the geometric center of the imaging area of ​​the charged particle beam scanning imaging system and the initial reference deflector is determined to be the reference deflector.

[0094] It should be explained that in some examples, see Figure 7 , step S130 includes the following steps S131~S133.

[0095] S131, determine whether the focus center of the scan verification image is located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system; if so, execute step S132; if not, execute step S133.

[0096] S132, determining the initial reference deflector as the reference deflector.

[0097] S133, adjusting the sampling window parameters corresponding to the scanning verification image (i.e., the sampling window parameters of the image collector) until the focusing center of the scanning verification image is adjusted to the geometric center of the imaging area of ​​the charged particle beam scanning imaging system and the initial reference deflector is determined to be the reference deflector.

[0098] In an embodiment of the present application, a scanning verification image is obtained based on the first channel scanning deflector (i.e., the initial reference deflector) arranged in sequence along the direction of movement of the charged particle beam, and the sampling window parameters of the image collector are adjusted based on the scanning verification image. By changing the image size or the image field of view (FOV), the focusing center of the scanning verification image is adjusted to the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, so as to determine the initial reference deflector as the reference deflector, thereby avoiding aberration problems such as imaging offset of the initial reference deflector; in this way, the scanning aberration of the reference deflector is reduced, and the accuracy of the scanning aberration correction in the subsequent steps is ensured, thereby realizing the precise correction of mechanical installation errors in the multi-channel scanning deflector.

[0099] In some embodiments, each channel scanning deflector includes a first deflection electrode and a second deflection electrode; the target scanning waveform includes a row scanning signal and a frame scanning signal. Figure 8 , step S700 includes the following step S710.

[0100] S710, determining a first scanning signal when the first deflection electrode scans for imaging and a second scanning signal when the second deflection electrode scans for imaging according to a row scanning signal, a frame scanning signal and a mechanical deviation angle.

[0101] In the embodiment of the present application, after the scanning waveform is corrected and the target scanning waveform is determined, the first scanning signal of the first deflection electrode and the second scanning signal of the second deflection electrode are calculated respectively, thereby improving the accuracy of scanning aberration correction.

[0102] In some embodiments, see Fig. 9 The charged particle beam scanning aberration correction method further includes the following step S800.

[0103] S800, when the imaging condition of the charged particle beam scanning imaging system changes, determining the scanning deviation angle of the deflector to be calibrated according to the changed imaging condition.

[0104] By way of example, the deflector to be calibrated may be one or more scanning deflectors in a charged particle beam scanning imaging system, but the present disclosure is not limited thereto.

[0105] Accordingly, please continue to refer to Fig. 9 , step S600 also includes the following step S610.

[0106] S610, determining an imaging compensation angle of the pattern generator according to the mechanical deviation angle and the scanning deviation angle, adjusting imaging parameters of the pattern generator according to the imaging compensation angle, and enabling the scanning waveform generator to output a target scanning waveform according to the adjusted imaging parameters.

[0107] It should be explained that in the actual scanning imaging process, there are often some situations where it is necessary to change the imaging conditions (such as the landing energy of the charged particle beam); however, the change in the landing energy of the charged particle beam will cause the distribution of the composite lens field (such as the electric field and the magnetic field) near the scanning deflector to change, affecting the electrostatic deflection field of the scanning deflector, thereby adversely affecting the deflection of the charged particle beam, causing the imaging conditions to change, so that the charged ion beam scanning imaging system cannot perform scanning imaging according to the parameters optimized under one imaging condition. In the embodiment of the present application, the scanning deviation angle is determined according to the changed imaging conditions, and the target scanning waveform is determined according to the scanning deviation angle caused by the mechanical deviation angle and the change in the imaging conditions (such as the landing energy) of the charged particle beam. In this way, under the premise of correcting the scanning aberration caused by the mechanical installation error, the scanning aberration caused by the change in the imaging conditions is also corrected, and the scanning aberration caused by the change in the electric field and magnetic field near the multi-channel deflector can be corrected when the landing energy of the charged particle beam changes, so as to achieve accurate imaging under different landing energy conditions.

[0108] In some embodiments, see Fig.10 , the imaging conditions include the landing energy of the charged particle beam; step S800 includes the following step S810.

[0109] S810, when the imaging condition of the charged particle beam scanning imaging system changes, obtaining a landing energy change of the charged particle beam, and determining a scanning deviation angle of the deflector to be calibrated according to the landing energy change.

[0110] Accordingly, in some examples, step S610 includes the following steps S611~S612.

[0111] S611, determining a first imaging compensation angle of the pattern generator according to the mechanical deviation angle, adjusting the imaging parameters of the pattern generator for the first time according to the first imaging compensation angle, and causing the scanning waveform generator to output a first target scanning waveform according to the imaging parameters adjusted for the first time.

[0112] S612, determining a second imaging compensation angle of the pattern generator according to a scanning deviation angle caused by a change in the landing energy of the charged particle beam, so as to make a second adjustment to the imaging parameters of the pattern generator according to the second imaging compensation angle, and causing the scanning waveform generator to output a second target scanning waveform according to the imaging parameters adjusted for the second time.

[0113] Based on the above example, please continue to see Fig.10 , after step S611, step S700 also includes the following step S721.

[0114] S721, performing a first correction on the scanning signal of the deflector to be calibrated when scanning and imaging according to the first target scanning waveform.

[0115] Based on the above example, please continue to see Fig.10 , after step S612, step S700 also includes the following step S722.

[0116] S722, performing a second correction on the scanning signal of the deflector to be calibrated when scanning and imaging according to the second target scanning waveform.

[0117] It should be noted that, in the embodiment of the present application, the scanning waveform of the deflector to be calibrated is corrected according to the mechanical deviation angle when scanning and imaging, so as to correct the mechanical installation error; in steps S612 and S722, the scanning waveform of the deflector to be calibrated is corrected according to the scanning deviation angle caused by the change of the landing energy of the charged particle beam, so as to correct the scanning aberration caused by the change of the imaging condition. In this way, the mechanical installation error and the imaging condition error are corrected in turn, and the scanning aberration of the charged particle beam scanning imaging system is further reduced, thereby improving the imaging quality.

[0118] Or, for other examples, see Fig.11 , step S600 also includes the following step S613.

[0119] S613, determining a total deviation angle according to a scanning deviation angle caused by a mechanical deviation angle and a landing energy change of a charged particle beam, determining a third imaging compensation angle of a graphic generator according to the total deviation angle, adjusting imaging parameters of the graphic generator according to the third imaging compensation angle, and causing a scanning waveform generator to output a third target scanning waveform according to the adjusted imaging parameters.

[0120] For example, the total deviation angle may be the sum of a mechanical deviation angle and a deviation angle caused by a change in the landing energy of the charged particle beam.

[0121] Based on the above example, please continue to see Fig.11 , after step S613, step S700 also includes the following step S723.

[0122] S723, performing comprehensive correction on the scanning signal of the deflector to be calibrated when scanning and imaging according to the third target scanning waveform.

[0123] It should be noted that in step S613 and step S723, the total deviation angle is determined according to the mechanical deviation angle and the scanning deviation angle caused by the change in the landing of the charged particle beam, so that the mechanical installation error and the imaging condition error caused by the change in the imaging condition are corrected simultaneously according to the total deviation angle, that is, the comprehensive correction of the mechanical installation error and the imaging condition error is achieved. In this way, the efficiency of scanning aberration correction is improved.

[0124] It should be understood that although Figure 5~Figure 11 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 5~Figure 11 At least part of the steps in the above may include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the steps or stages in other steps. Figure 5~Figure 11 At least part of the steps in the above method can also be adaptively applied to the same embodiments, that is: Figure 5~Figure 11 At least some of the steps may also be used in a cross-coordinated manner.

[0125] In order to more clearly explain the charged particle beam scanning aberration correction method in some of the above embodiments, Figure 12~Figure 15 Some possible implementations of the charged particle beam scanning aberration correction method are described in detail.

[0126] In some embodiments, the charged particle beam scanning aberration correction method includes the following steps S100 - S700 .

[0127] In step S100, a reference deflector and a deflector to be calibrated are determined from the multi-channel scanning deflectors.

[0128] It should be noted that, for ease of understanding, the present application uses the example of the deflector to be calibrated including a two-channel scanning deflector in the following embodiments for explanation; however, it can be understood that the deflector to be calibrated in the embodiments of the present application can be one or more scanning deflectors in a charged particle beam scanning imaging system, and the present application does not impose any restrictions on this.

[0129] In some embodiments, step S100 includes the following steps S110 to S130.

[0130] In step S110 , the first channel scanning deflector arranged in sequence along the moving direction of the charged particle beam is used as the initial reference deflector, and the second channel and subsequent channel scanning deflectors are deflectors to be calibrated.

[0131] In step S120, refer to Fig.12 , obtain a scanning verification image A of the initial reference deflector against the target reference pattern.

[0132] It should be noted that the scanning verification image A refers to a scanning image obtained by scanning the target reference pattern when the initial reference deflector works alone.

[0133] In step S130, it is determined whether the focusing center of the scanning verification image A is located at the geometric center of the imaging area E of the charged particle beam scanning imaging system. In response to the focusing center of the scanning verification image A being located at the geometric center of the imaging area E of the charged particle beam scanning imaging system, the initial reference deflector is determined to be the reference deflector; and in response to the focusing center of the scanning verification image A not being located at the geometric center of the imaging area E of the charged particle beam scanning imaging system, the sampling window parameters corresponding to the scanning verification image A (i.e., the sampling window parameters of the image acquisition device 32) are adjusted until the focusing center of the scanning verification image A is adjusted to the geometric center of the imaging area E of the charged particle beam scanning imaging system and the initial reference deflector is determined to be the reference deflector.

[0134] It should be noted that the scanned verification image A in step S120 and the first scanned image B and the second scanned image in step S200 are all acquired by the image collector 32 .

[0135] For example, the sampling window parameters include image size and / or image field of view (FOV for short).

[0136] In some examples, step S130 includes the following steps S131 to S133.

[0137] In step S131, it is determined whether the focus center of the scan verification image A is located at the geometric center of the imaging area E of the charged particle beam scanning imaging system; if so, step S132 is executed; if not, step S133 is executed.

[0138] In step S132 , the initial reference deflector is determined as the reference deflector.

[0139] In step S133, refer to Fig.12 , adjust the sampling window parameters corresponding to the scanning verification image A (i.e., the sampling window parameters of the image collector 32) until the focusing center of the scanning verification image A is adjusted to the geometric center of the imaging area E of the charged particle beam scanning imaging system and the initial reference deflector is determined to be the reference deflector.

[0140] In step S200, refer to Fig.13 , respectively obtain a first scanning image B of the reference deflector for the characteristic pattern and a second scanning image B of the deflector to be calibrated for the same characteristic pattern.

[0141] It should be noted that the target reference graph and the characteristic graph can be the same graph or different graphs, and this application does not impose any restrictions on this.

[0142] It should be explained that the first scanning image B refers to the scanning image obtained by scanning the characteristic pattern when the reference deflector works alone; the second scanning image refers to the scanning image obtained by scanning the characteristic pattern when the deflector to be calibrated works alone.

[0143] For example, please continue to see Fig.13 , taking the example that the deflector to be calibrated includes a two-channel scanning deflector; the second scanning image includes a first scanning sub-image C1 obtained by scanning the characteristic pattern when the first deflector to be calibrated works alone, and a second scanning sub-image C2 obtained by scanning the characteristic pattern when the second deflector to be calibrated works alone.

[0144] In step S300, please continue to refer to Fig.13 , determine the first scanning deflection angle of the reference deflector according to the first scanning image B, determine the second scanning deflection angle of the deflector to be calibrated according to the second scanning image, and determine the scanning deflection angle difference according to the difference between the first scanning deflection angle and the second scanning deflection angle.

[0145] It should be noted that the scanning deflection angle difference refers to the difference between the second scanning deflection angle of the deflector to be calibrated in each channel and the first scanning deflection angle of the reference deflector.

[0146] For example, the deflector to be calibrated includes a two-channel scanning deflector; the deflector to be calibrated includes a first deflector to be calibrated and a second deflector to be calibrated; please continue to refer to Fig.13 , the first scanning deflection angle of the reference deflector is, for example, , the second scanning deflection angle corresponding to the first scanning sub-image C1 of the first deflector to be calibrated is, for example, , the second scanning deflection angle corresponding to the second scanning sub-image C2 of the second deflector to be calibrated is, for example, ;in, .

[0147] According to the above example, the first scanning deflection angle difference between the first deflector to be calibrated and the reference deflector is The second scanning deflection angle difference between the second deflector to be calibrated and the reference deflector is ;in, and It can be calculated according to the following formula.

[0148] ; .

[0149] in, is the first scanning deflection angle, is the first scan deflection angle difference, is the second scanning deflection angle corresponding to the second scanning image, is the second scanning deflection angle difference, is the second scanning deflection angle corresponding to the second scanned image.

[0150] In step S400, a design angle difference of the installation angle between the reference deflector and the deflector to be calibrated is obtained.

[0151] It should be noted that the design angle difference refers to the difference between the design angle of the deflector to be calibrated in each channel and the design angle of the reference deflector.

[0152] For example, Fig.14 As shown in Figure (a), the design angle of the reference deflector is, for example, ;like Fig.14 As shown in Figure (b) of FIG. 1 , the design angle of the first deflector to be calibrated is, for example, ;like Fig.14 As shown in Figure (c) of FIG. 1 , the design angle of the second deflector to be calibrated is, for example, ;in, ;For example: =45°, =27.5°, =17.5°.

[0153] According to the above example, the first design angle difference between the reference deflector and the first deflector to be calibrated is , the second design angle difference between the reference deflector and the second deflector to be calibrated is ;in, and It can be calculated according to the following formula.

[0154] ; .

[0155] in, is the first design angle difference, is the design angle of the reference deflector, is the design angle of the first deflector to be calibrated, is the second design angle difference, is the design angle of the second deflector to be calibrated.

[0156] In step S500, a mechanical deviation angle is determined according to a difference between the scan deflection angle difference and the design angle difference.

[0157] For example, the first mechanical deviation angle between the first deflector to be calibrated and the reference deflector is , the second mechanical deviation angle between the second deflector to be calibrated and the reference deflector is ;in, and It can be calculated according to the following formula.

[0158] ; .

[0159] in, is the first mechanical deviation angle, is the first scan deflection angle difference, is the first design angle difference, is the first scanning deflection angle, is a second scanning deflection angle corresponding to the second scanning image; is the second mechanical deviation angle, is the second scan deflection angle difference, is the second design angle difference, is the second scanning deflection angle corresponding to the second scanned image.

[0160] In step S600, the imaging compensation angle of the pattern generator 31 is determined according to the mechanical deviation angle, so as to adjust the imaging parameters of the pattern generator 31 according to the imaging compensation angle, and enable the scanning waveform generator to output the target scanning waveform according to the adjusted imaging parameters.

[0161] In step S700, the scanning signal of the deflector to be calibrated during scanning imaging is corrected according to the target scanning waveform.

[0162] Please note that Fig.14 or Fig.15 The scanning deflector includes a first deflection electrode 21 and a second deflection electrode 22; the target scanning waveform includes a row scanning signal V L and frame scan signal V F .

[0163] For example, see Fig.15 The first deflection electrode 21 can be arranged on two opposite sides along a first direction (for example, the X direction) on the motion trajectory of the charged particle beam, and the second deflection electrode 22 can be arranged on two opposite sides along a second direction (for example, the Y direction) on the motion trajectory of the charged particle beam; wherein the electric field (or magnetic field direction) of the first deflection electrode 21 is along the first direction (for example, the X direction), and the electric field (or magnetic field direction) of the second deflection electrode 22 is along the second direction (for example, the Y direction).

[0164] In some embodiments, step S700 includes the following step S710.

[0165] In step S710, according to the row scanning signal V L , frame scanning signal V F and the mechanical deviation angle, determine the first scanning signal Dx when the first deflection electrode 21 scans the image and the second scanning signal Dy when the second deflection electrode 22 scans the image.

[0166] For example, the first scanning signal Dx of the first deflection electrode 21 is to convert the row scanning signal V L The second scanning signal Dy of the second deflection electrode 22 is the frame scanning signal V F The vector is decomposed into signal components in a second direction (eg, Y direction).

[0167] By way of example, the first scan signal Dx and the second scan signal Dy both include a voltage scan signal and / or a current scan signal.

[0168] For example, for the first deflector to be calibrated: the first scanning signal Dx1 of the first deflection electrode 21 and the second scanning signal Dy1 of the second deflection electrode 22 can be calculated according to the following formula.

[0169] ; .

[0170] Wherein, Dx1 is the first scanning signal of the first deflector to be calibrated, V L is the line scanning signal, is the first mechanical deviation angle of the first deflector to be calibrated, V F is a frame scanning signal, and Dy1 is a second scanning signal of the first deflector to be calibrated.

[0171] For example, for the second deflector to be calibrated: the first scanning signal Dx2 and the second scanning signal Dy2 of the first deflection electrode 21 thereof can be calculated according to the following formulas.

[0172] ; .

[0173] Wherein, Dx2 is the first scanning signal of the second deflector to be calibrated, V L is the line scanning signal, is the second mechanical deviation angle of the second deflector to be calibrated, V F is a frame scanning signal, and Dy2 is a second scanning signal of the second deflector to be calibrated.

[0174] In some embodiments, the charged particle beam scanning aberration correction method further includes the following step S800 .

[0175] In step S800, when the imaging condition of the charged particle beam scanning imaging system changes, the scanning deviation angle of the deflector to be calibrated is determined according to the changed imaging condition.

[0176] Accordingly, step S600 includes the following step S610.

[0177] In step S610, the imaging compensation angle of the pattern generator 31 is determined according to the mechanical deviation angle and the scanning deviation angle, so as to adjust the imaging parameters of the pattern generator 31 according to the imaging compensation angle, and enable the scanning waveform generator to output the target scanning waveform according to the adjusted imaging parameters.

[0178] In some embodiments, step S800 includes the following step S810.

[0179] In step S810, when the imaging condition of the charged particle beam scanning imaging system changes, the landing energy change of the charged particle beam is obtained, and the scanning deviation angle of the deflector to be calibrated is determined according to the landing energy change.

[0180] By way of example, the imaging conditions include, but are not limited to, a field of view (FOV), a landing energy of a charged particle beam, and / or a scanning direction of the charged particle beam, and the like.

[0181] It should be noted that, in the embodiment of the present application, other imaging conditions remain unchanged, and the correction of the imaging condition error caused by the landing energy of the charged particle beam is taken as an example.

[0182] For example, the value range of the field of view (FOV) includes 1μm~100μm; the value of the field of view (FOV) can be, for example, 1μm, 10μm, 20μm, 30μm, 40μm, 50μm, 51.2μm, 60μm, 70μm, 80μm, 90μm, or 100μm, etc.

[0183] It should be noted that the change of the landing energy of the charged particle beam can be achieved by controlling the electrode voltage of the electrostatic lens under the objective lens of the charged particle beam scanning imaging system and the platform voltage.

[0184] For example, when the electrode voltage of the electrostatic lens changes from 3800V to 3500V, and the electrode voltage of the electrostatic lens at the bottom of the landing field scanning the sample surface changes from -2000V to 500V, the landing energy of the charged particle beam decreases from 800eV to 500eV. Then, since the change in the landing energy of the charged particle beam will cause the change in the electric field (or magnetic field) distribution of the electrostatic lens, the scanning voltage of the scanning deflector will change from 124.3V to 123.646V, and the blurred size of the charged particle beam spot will change from 0.00362μm to 0.00455μm; accordingly, the scanning deflection angle of the scanning deflector changes from -112.819° to -112.601°; it should be explained that the above data can be obtained based on theoretical calculations or actual measurements.

[0185] Combined with the above example, the scanning deviation angle can be determined according to the following formula: : .

[0186] Accordingly, in some embodiments, step S600 includes steps S611 to S612.

[0187] In step S611, a first imaging compensation angle of the pattern generator 31 is determined according to the mechanical deviation angle, so that the imaging parameters of the pattern generator 31 are adjusted for the first time according to the first imaging compensation angle, and the scanning waveform generator outputs a first target scanning waveform according to the imaging parameters adjusted for the first time.

[0188] Accordingly, step S700 includes the following step S721.

[0189] In step S721, a first correction is performed on the scanning signal of the deflector to be calibrated when scanning and imaging according to the first target scanning waveform.

[0190] It should be noted that the specific implementation process of step S611 can refer to step S600 in the aforementioned embodiment; the specific implementation process of step S721 can refer to step S710 in the aforementioned embodiment, which will not be described in detail here.

[0191] In step S612, the second imaging compensation angle of the graphic generator 31 is determined according to the scanning deviation angle caused by the change in the landing energy of the charged particle beam, so that the imaging parameters of the graphic generator 31 are adjusted for the second time according to the second imaging compensation angle, and the scanning waveform generator outputs a second target scanning waveform according to the imaging parameters adjusted for the second time.

[0192] Accordingly, step S700 also includes the following step S722.

[0193] In step S722, the scanning signal of the deflector to be calibrated when scanning and imaging is performed for the second time is calibrated according to the second target scanning waveform.

[0194] For example, in the second calibration of step S722 , the first scanning signal Dx3 of the first deflection electrode 21 and the second scanning signal Dy3 of the second deflection electrode 22 of the deflector to be calibrated can be calculated according to the following formula.

[0195] ; .

[0196] Wherein, Dx3 is the first scanning signal in the second calibration, Dy3 is the second scanning signal in the second calibration, V L is the line scan signal, V F is the frame scanning signal, is the scanning deviation angle.

[0197] It is worth mentioning that the correction process for the imaging condition error in some of the above-mentioned embodiments (i.e., the second correction process) can be performed on any one or more scanning deflectors in the charged particle beam scanning imaging system; that is, the correction of the imaging condition error can be performed on the reference deflector, or on one or more deflectors to be calibrated; although the present application is described using one of the scanning deflectors as an example, it is not limited to this.

[0198] Alternatively, in some other embodiments, step S600 includes the following step S613.

[0199] In step S613, the total deviation angle is determined according to the scanning deviation angle caused by the mechanical deviation angle and the change in the landing energy of the charged particle beam, and the third imaging compensation angle of the graphic generator 31 is determined according to the total deviation angle, so as to adjust the imaging parameters of the graphic generator 31 according to the third imaging compensation angle, and enable the scanning waveform generator to output the third target scanning waveform according to the adjusted imaging parameters.

[0200] For example, the total deviation angle Can be the mechanical deviation angle Scanning deviation angle caused by the change of charged particle beam landing energy The sum of the additions; that is, .

[0201] Accordingly, step S700 also includes the following step S723.

[0202] In step S723, the scanning signal of the deflector to be calibrated during scanning imaging is comprehensively corrected according to the third target scanning waveform.

[0203] According to the above example, the first scanning signal Dx4 and the second scanning signal Dy4 comprehensively corrected in step S723 can be calculated according to the following formula.

[0204] ; ; .

[0205] Wherein, Dx4 is the first scanning signal in the comprehensive calibration, Dy4 is the second scanning signal in the comprehensive calibration, V L is the line scan signal, V F is the frame scanning signal, is the total deviation angle, Scan the mechanical deviation angle of the deflector for any channel in the deflector to be calibrated, The scanning deviation angle of the deflector for any channel in the deflector to be calibrated.

[0206] It should be noted that the comprehensive calibration process in some of the above embodiments can be performed on any one or more scanning deflectors to be calibrated in the charged particle beam scanning imaging system; wherein the first scanning signal Dx4 and the second scanning signal Dy4 of each channel scanning deflector are based on the mechanical deviation angle corresponding to the channel scanning deflector. and scanning deviation angle Calculated.

[0207] The present application also provides a charged particle beam scanning aberration correction system according to some embodiments, and the charged particle beam scanning aberration correction system can be used to perform the steps of the charged particle beam scanning aberration correction method as described in any of the aforementioned embodiments of the present application, so as to correct the scanning aberration of the charged particle beam scanning imaging system. The charged particle beam scanning aberration correction system also has the technical advantages of the aforementioned charged particle beam scanning aberration correction method. It should be noted that, for the parts that are the same or corresponding to the above embodiments, reference can be made to the corresponding description of the aforementioned embodiments, and will not be described in detail below.

[0208] Please note that Figure 1 and Figure 2 The charged particle beam scanning imaging system includes an electron optical lens barrel 1, a detector module T, a multi-channel scanning deflector 2 and a multi-channel scanning waveform generator S.

[0209] By way of example, the electron optical lens barrel 1 comprises an electron source 11 , a charged particle beam accelerating structure, at least one focusing lens 12 , at least one aperture 13 , an stigmator and the like.

[0210] For example, when the number of the focusing lenses 12 is three, the first-stage lens is used to adjust and pre-focus the beam size of the charged particle beam, the second-stage lens and the aperture 13 with selectable aperture size act on the charged particle beam as a whole, so that the opening angle of the charged particle beam passing through the aperture 13 is adjustable, and the final focusing lens 12 is also used to focus the charged particle beam on the sample surface.

[0211] In some examples, the multi-channel scanning deflector 2 includes scanning deflectors of multiple channels arranged in sequence along the moving direction of the charged particle beam.

[0212] In some examples, the multi-channel scanning waveform generator S includes scanning waveform generators for multiple channels respectively connected to the scanning deflectors of each channel; wherein each channel scanning waveform generator can be connected to each channel scanning deflector one by one so that the scanning signal of each channel scanning deflector can be independently adjusted.

[0213] In some embodiments, the charged particle beam scanning aberration correction system is used to correct the scanning aberration of the charged particle beam scanning imaging system; see Figure 5 The charged particle beam scanning imaging system includes a multi-channel scanning deflector arranged in sequence along the moving direction of the charged particle beam, and a multi-channel scanning waveform generator S connected to each channel scanning deflector. The multi-channel scanning deflector includes a reference deflector and a deflector to be calibrated.

[0214] In some embodiments, see Fig.16The charged particle beam scanning aberration correction system includes an image acquisition module 3, an image processing module 4, a data processing module 5 and a scanning control module 6.

[0215] The image acquisition module 3 comprises a pattern generator 31 and an image collector 32. The image collector 32 is configured to respectively acquire a first scanning image B of a characteristic pattern of a reference deflector pair and a second scanning image of the same characteristic pattern of a deflector pair to be calibrated.

[0216] The image processing module 4 is connected to the image collector 32. The image processing module 4 is configured to determine a first scanning deflection angle of the reference deflector according to the first scanning image B, and determine a second scanning deflection angle of the deflector to be calibrated according to the second scanning image.

[0217] The data processing module 5 is connected to the image processing module 4 and the pattern generator 31. The data processing module 5 is configured to: determine the scanning deflection angle difference according to the difference between the first scanning deflection angle and the second scanning deflection angle; obtain the design angle difference of the installation angle between the reference deflector and the deflector to be calibrated; determine the mechanical deviation angle according to the difference between the scanning deflection angle difference and the design angle difference; determine the imaging compensation angle of the pattern generator 31 according to the mechanical deviation angle.

[0218] The scanning control module 6 is connected to the pattern generator 31 and the data processing module 5. The scanning control module 6 is configured to: adjust the imaging parameters of the pattern generator 31 according to the imaging compensation angle, and make the scanning waveform generator output the target scanning waveform according to the adjusted imaging parameters; and correct the scanning signal of the deflector to be calibrated when scanning and imaging according to the target scanning waveform.

[0219] For example, the design angle difference obtained by the data processing module 5 is obtained by simulation calculation based on the theoretical design value of the installation angle.

[0220] For example, take the deflector to be calibrated as comprising a two-channel scanning deflector; the scanning control module 6 is further configured to: according to the scanning voltage ratio (or scanning current ratio) between the first channel scanning deflector and the second channel scanning deflector and the installation angle ratio between the first channel scanning deflector and the second channel scanning deflector, correct the scanning waveform based on the imaging compensation angle and output the target scanning waveform to correct the scanning aberration when the scanning deflector scans the image.

[0221] In the embodiment of the present application, the scanning deflection angle difference between the first scanning image of the reference deflector and the second scanning image of the deflector to be calibrated, as well as the design angle difference of the installation angle between the reference deflector and the deflector to be calibrated are obtained by the data processing module 5, and the mechanical deviation angle is determined according to the difference between the scanning deflection angle difference and the design angle difference, so as to determine the imaging compensation angle of the pattern generator according to the mechanical deviation angle. In this way, the embodiment of the present application determines the mechanical deviation angle based on the scanning deflection angle difference obtained by actual scanning and the design angle difference obtained by theoretical calculation, that is, determines the angle compensation amount required to correct the mechanical installation error; and determines the imaging compensation angle of the pattern generator according to the mechanical deviation angle, and outputs the target scanning waveform based on the imaging parameters adjusted by the pattern generator according to the imaging compensation angle by the scanning waveform generator, so that the scanning control module 6 corrects the scanning signal of the deflector to be calibrated according to the target scanning waveform to compensate for the mechanical installation error; the precise correction of the mechanical installation error in the multi-channel scanning deflector is realized, and the scanning aberration of the charged particle beam scanning imaging system is effectively reduced, thereby improving the imaging quality.

[0222] In some examples, the deflector to be calibrated includes at least two channel scanning deflectors; the second scanning image of the characteristic pattern of each channel scanning deflector in the deflector to be calibrated is obtained by scanning the characteristic pattern by the channel scanning deflector alone; the target scanning waveform of each channel scanning deflector in the deflector to be calibrated is determined based on the mechanical deviation angle corresponding to the channel scanning deflector.

[0223] For example, the second scanning image of the characteristic pattern of each channel scanning deflector in the deflector to be calibrated can be obtained by collecting the characteristic pattern by the image collector 32 when the deflector to be calibrated works alone.

[0224] In some examples, a first scan image of a reference deflector and a second scan image of a deflector to be calibrated are obtained for the same feature pattern under the same imaging conditions.

[0225] In some embodiments, the image acquisition device 32 is further configured to: before acquiring the first scanning image of the reference deflector for the characteristic pattern, use the first channel scanning deflector arranged in sequence along the movement direction of the charged particle beam as the initial reference deflector, and the second channel and subsequent channel scanning deflectors as the deflectors to be calibrated, and acquire a scanning verification image of the initial reference deflector for the target reference pattern.

[0226] For some examples, see Fig.17, the charged particle beam scanning aberration correction system also includes a reference deflector determination module 7. The reference deflector determination module 7 is connected to the image collector 32 and the scanning control module 6. The reference deflector determination module 7 is configured to: determine whether the focus center of the scanning verification image A is located at the geometric center of the imaging area E of the charged particle beam scanning imaging system, and in response to the focus center of the scanning verification image A being located at the geometric center of the imaging area E of the charged particle beam scanning imaging system, determine that the initial reference deflector is the reference deflector; and in response to the focus center of the scanning verification image A not being located at the geometric center of the imaging area E of the charged particle beam scanning imaging system, adjust the sampling window parameters of the image collector until the focus center of the scanning verification image A is adjusted to the geometric center of the imaging area E of the charged particle beam scanning imaging system and determine that the initial reference deflector is the reference deflector.

[0227] In some examples, the reference deflector determination module 7 is further configured to: determine whether the focus center of the scan verification image A is located at the geometric center of the imaging area E of the charged particle beam scanning imaging system. If so, the initial reference deflector is determined to be the reference deflector; if not, the sampling window parameters of the image collector 32 are adjusted until the focus center of the scan verification image A is adjusted to the geometric center of the imaging area E of the charged particle beam scanning imaging system and the initial reference deflector is determined to be the reference deflector.

[0228] In some examples, the scanning deflector includes a first deflection electrode 21 and a second deflection electrode 22. The target scanning waveform includes a line scanning signal and a frame scanning signal. The data processing module 5 is further configured to: determine a first scanning signal when the first deflection electrode 21 scans an image and a second scanning signal when the second deflection electrode 22 scans an image according to the line scanning signal, the frame scanning signal and the mechanical deviation angle.

[0229] In some embodiments, the data processing module 5 is further configured to: determine a scanning deviation angle according to the changed imaging conditions when the imaging conditions of the charged particle beam scanning imaging system change; and determine an imaging compensation angle of the graphic generator 31 based on the mechanical deviation angle and the scanning deviation angle.

[0230] In some embodiments, the imaging condition of the charged particle beam scanning imaging system includes the landing energy of the charged particle beam. The data processing module 5 is further configured to: when the imaging condition of the charged particle beam scanning imaging system changes, obtain the landing energy change of the charged particle beam, and determine the scanning deviation angle of the deflector to be calibrated according to the landing energy change.

[0231] According to the above embodiments, in some examples, the data processing module 5 is further configured to: determine a first imaging compensation angle of the graphic generator 31 according to a mechanical deviation angle; and determine a second imaging compensation angle of the graphic generator 31 according to a scanning deviation angle caused by changes in the landing energy of the charged particle beam.

[0232] Correspondingly, the scanning control module 6 is also configured to: make a first adjustment to the imaging parameters of the graphic generator 31 according to the first imaging compensation angle, and enable the scanning waveform generator to output a first target scanning waveform according to the imaging parameters adjusted for the first time, so as to make a first correction to the scanning signal when the deflector to be calibrated is scanned and imaged according to the first target scanning waveform; and make a second adjustment to the imaging parameters of the graphic generator 31 according to the second imaging compensation angle, and enable the scanning waveform generator to output a second target scanning waveform according to the imaging parameters adjusted for the second time, so as to make a second correction to the scanning signal when the deflector to be calibrated is scanned and imaged according to the second target scanning waveform.

[0233] In some other examples, the data processing module 5 is further configured to determine a total deviation angle according to a mechanical deviation angle and a scanning deviation angle caused by a change in landing energy of the charged particle beam.

[0234] Correspondingly, the scanning control module 6 is also configured to: determine the third imaging compensation angle of the graphic generator 31 according to the total deviation angle, so as to adjust the imaging parameters of the graphic generator 31 according to the third imaging compensation angle, and enable the scanning waveform generator to output the third target scanning waveform according to the adjusted imaging parameters, so as to perform comprehensive correction on the scanning signal when the deflector to be calibrated is scanned and imaged according to the third target scanning waveform.

[0235] In the description of this specification, the description with reference to the terms "some embodiments", "some examples", "exemplarily", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0236] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0237] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A charged particle beam scanning aberration correction method, characterized in that: Used to correct the scanning aberration of a charged particle beam scanning imaging system; the charged particle beam scanning imaging system comprises a multi-channel scanning deflector arranged in sequence along the moving direction of the charged particle beam and a multi-channel scanning waveform generator respectively connected to each channel scanning deflector; The charged particle beam scanning aberration correction method comprises: determining a reference deflector and a deflector to be calibrated from the multi-channel scanning deflectors; Respectively acquiring a first scanning image of the reference deflector with respect to a characteristic pattern and a second scanning image of the deflector to be calibrated with respect to the same characteristic pattern; determining a first scanning deflection angle of the reference deflector according to the first scanning image, determining a second scanning deflection angle of the deflector to be calibrated according to the second scanning image, and determining a scanning deflection angle difference according to a difference between the first scanning deflection angle and the second scanning deflection angle; Obtaining a design angle difference between the installation angles of the reference deflector and the deflector to be calibrated; Determining a mechanical deviation angle according to a difference between the scanning deflection angle difference and the design angle difference; Determining an imaging compensation angle of a pattern generator according to the mechanical deviation angle, so as to adjust an imaging parameter of the pattern generator according to the imaging compensation angle, and causing the scanning waveform generator to output a target scanning waveform according to the adjusted imaging parameter; The scanning signal of the deflector to be calibrated during scanning imaging is corrected according to the target scanning waveform.

2. The charged particle beam scanning aberration correction method according to claim 1, characterized in that: The deflector to be calibrated includes at least two-channel scanning deflectors; wherein, The second scanning image of the characteristic pattern by the scanning deflector of each channel in the deflector to be calibrated is obtained by scanning the characteristic pattern by the scanning deflector of the channel alone; The target scanning waveform of the scanning deflector in each channel of the deflector to be calibrated is determined based on the mechanical deviation angle corresponding to the scanning deflector in the channel.

3. The charged particle beam scanning aberration correction method according to claim 1, characterized in that: The first scanning image of the reference deflector and the second scanning image of the deflector to be calibrated are obtained by scanning the same characteristic pattern under the same imaging conditions.

4. The charged particle beam scanning aberration correction method according to claim 1, characterized in that: The step of determining a reference deflector and a deflector to be calibrated from the multi-channel scanning deflectors comprises: The first channel scanning deflector arranged in sequence along the moving direction of the charged particle beam is used as the initial reference deflector, and the second channel and subsequent channel scanning deflectors are used as the deflectors to be calibrated; Acquire a scanning verification image of the initial reference deflector on a target reference pattern; Determine whether the focusing center of the scanning verification image is located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system; in response to the focusing center of the scanning verification image being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, determine that the initial reference deflector is the reference deflector; and in response to the focusing center of the scanning verification image not being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, adjust the sampling window parameters corresponding to the scanning verification image until the focusing center of the scanning verification image is adjusted to the geometric center of the imaging area of ​​the charged particle beam scanning imaging system and determine that the initial reference deflector is the reference deflector.

5. The charged particle beam scanning aberration correction method according to claim 1, characterized in that: The scanning deflector of each channel includes a first deflection electrode and a second deflection electrode; the target scanning waveform includes a row scanning signal and a frame scanning signal; and the scanning signal of the deflector to be calibrated during scanning imaging according to the target scanning waveform is corrected, including: A first scanning signal when the first deflection electrode scans for imaging and a second scanning signal when the second deflection electrode scans for imaging are determined according to the row scanning signal, the frame scanning signal and the mechanical deviation angle.

6. The charged particle beam scanning aberration correction method according to claim 1, characterized in that: Also includes: When the imaging condition of the charged particle beam scanning imaging system changes, determining the scanning deviation angle of the deflector to be calibrated according to the changed imaging condition; The method includes determining an imaging compensation angle of a pattern generator according to the mechanical deviation angle, adjusting imaging parameters of the pattern generator according to the imaging compensation angle, and causing the scanning waveform generator to output a target scanning waveform according to the adjusted imaging parameters, including: The imaging compensation angle of the pattern generator is determined according to the mechanical deviation angle and the scanning deviation angle, so as to adjust the imaging parameters of the pattern generator according to the imaging compensation angle, and enable the scanning waveform generator to output the target scanning waveform according to the adjusted imaging parameters.

7. The charged particle beam scanning aberration correction method according to claim 6, characterized in that: The imaging condition includes the landing energy of the charged particle beam; when the imaging condition of the charged particle beam scanning imaging system changes, determining the scanning deviation angle of the deflector to be calibrated according to the changed imaging condition includes: When the imaging condition of the charged particle beam scanning imaging system changes, acquiring a landing energy change of the charged particle beam, and determining the scanning deviation angle of the deflector to be calibrated according to the landing energy change; The step of determining the imaging compensation angle of the pattern generator according to the mechanical deviation angle and the scanning deviation angle, adjusting the imaging parameters of the pattern generator according to the imaging compensation angle, and causing the scanning waveform generator to output the target scanning waveform according to the adjusted imaging parameters, comprises: Determine a first imaging compensation angle of the pattern generator according to the mechanical deviation angle, adjust the imaging parameters of the pattern generator for the first time according to the first imaging compensation angle, and make the scanning waveform generator output a first target scanning waveform according to the imaging parameters adjusted for the first time; determine a second imaging compensation angle of the pattern generator according to the scanning deviation angle caused by the change in the landing energy of the charged particle beam, adjust the imaging parameters of the pattern generator for the second time according to the second imaging compensation angle, and make the scanning waveform generator output a second target scanning waveform according to the imaging parameters adjusted for the second time; Alternatively, a total deviation angle is determined based on the mechanical deviation angle and the scanning deviation angle caused by the change in the landing energy of the charged particle beam, and a third imaging compensation angle of the graphic generator is determined based on the total deviation angle, so as to adjust the imaging parameters of the graphic generator according to the third imaging compensation angle, and enable the scanning waveform generator to output a third target scanning waveform according to the adjusted imaging parameters.

8. A charged particle beam scanning aberration correction system, characterized in that: The method is used to perform the steps of the charged particle beam scanning aberration correction method as described in any one of claims 1 to 7 to correct the scanning aberration of the charged particle beam scanning imaging system; the charged particle beam scanning imaging system comprises a multi-channel scanning deflector arranged in sequence along the moving direction of the charged particle beam and a multi-channel scanning waveform generator respectively connected to each channel scanning deflector; the multi-channel scanning deflector comprises a reference deflector and a deflector to be calibrated; The charged particle beam scanning aberration correction system comprises: An image acquisition module, comprising a pattern generator and an image collector; wherein the image collector is configured to: respectively acquire a first scanning image of the reference deflector for a characteristic pattern and a second scanning image of the deflector to be calibrated for the same characteristic pattern; an image processing module connected to the image collector and configured to: determine a first scanning deflection angle of the reference deflector according to the first scanning image, and determine a second scanning deflection angle of the deflector to be calibrated according to the second scanning image; a data processing module connected to the image processing module and the pattern generator, and configured to: determine a scanning deflection angle difference according to a difference between the first scanning deflection angle and the second scanning deflection angle; obtain a design angle difference of the installation angle between the reference deflector and the deflector to be calibrated; determine a mechanical deviation angle according to a difference between the scanning deflection angle difference and the design angle difference; and determine an imaging compensation angle of the pattern generator according to the mechanical deviation angle; The scanning control module is connected to the graphic generator and the data processing module, and is configured to: adjust the imaging parameters of the graphic generator according to the imaging compensation angle, and enable the scanning waveform generator to output a target scanning waveform according to the adjusted imaging parameters; and correct the scanning signal of the deflector to be calibrated during scanning imaging according to the target scanning waveform.

9. The charged particle beam scanning aberration correction system according to claim 8, characterized in that: Also includes: A reference deflector determination module; wherein, The image collector is further configured to: before acquiring the first scanning image of the reference deflector on the characteristic pattern, use the first channel scanning deflector arranged in sequence along the moving direction of the charged particle beam as the initial reference deflector, and acquire a scanning verification image of the initial reference deflector on the target reference pattern; The reference deflector determination module is connected to the image collector and the scanning control module, and is configured to: determine whether the focusing center of the scanning verification image is located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system; in response to the focusing center of the scanning verification image being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, determine that the initial reference deflector is the reference deflector; and in response to the focusing center of the scanning verification image not being located at the geometric center of the imaging area of ​​the charged particle beam scanning imaging system, adjust the sampling window parameters of the image collector until the focusing center of the scanning verification image is adjusted to the geometric center of the imaging area of ​​the charged particle beam scanning imaging system and determine that the initial reference deflector is the reference deflector.

10. The charged particle beam scanning aberration correction system according to claim 8, characterized in that: The imaging conditions of the charged particle beam scanning imaging system include the landing energy of the charged particle beam; the data processing module is also configured to: when the imaging conditions of the charged particle beam scanning imaging system change, obtain the landing energy change of the charged particle beam, and determine the scanning deviation angle according to the landing energy change; determine the imaging compensation angle of the graphic generator according to the mechanical deviation angle and the scanning deviation angle.

Images