A focus control method and device, scanning electron microscope and storage medium

Abstract

This application provides a focusing control method, comprising: dividing a selected region of interest into at least two sub-regions based on feature information of the sample surface; configuring corresponding focusing and astigmatism adjustment modes for each sub-region; and taking line-by-line images of the entire region of interest based on the focusing and astigmatism adjustment modes to obtain corresponding images. This application also provides an apparatus, a scanning electron microscope, and a storage medium for implementing the method.

Description

Technical Field

[0001] This application relates to the field of electron microscopy, and more particularly to a focusing control method, apparatus, scanning electron microscope, and storage medium. Background Technology

[0002] Most high-end field emission scanning electron microscopes on the market now have the function of automatic imaging of large areas. When imaging large-area samples, a good scanning electron microscope needs to be able to automatically perform focusing, astigmatism and other image adjustment operations, in order to obtain clear images in the large area being imaged.

[0003] However, currently, automated imaging of large areas can only select a single method for adjusting focus and astigmatism. This single method is determined based on the type of sample. For large-area samples, this method cannot cover the entire sample, and often some areas cannot be adjusted clearly, resulting in blurry images that require manual reshooting. Summary of the Invention

[0004] In view of this, embodiments of this application aim to provide a focusing control method, apparatus, scanning electron microscope, and storage medium that enables the acquisition of clear images of the entire area during large-area scanning imaging, reducing the need for re-image capture.

[0005] The technical solution of this application embodiment is implemented as follows:

[0006] This application provides a focusing control method, the method comprising:

[0007] Based on the feature information of the sample surface, the selected region of interest is divided into at least two sub-regions;

[0008] Configure corresponding focusing and astigmatism adjustment methods for each sub-region;

[0009] Based on the aforementioned focusing and astigmatism adjustment method, the entire region of interest is photographed line by line to obtain the corresponding image.

[0010] In this embodiment of the application, the feature information of the surface of the sample to be tested includes, but is not limited to, one or more of the following:

[0011] high;

[0012] The height difference between adjacent areas;

[0013] Surface roughness;

[0014] The number of sample features included;

[0015] The level of electron beam irradiation that can be tolerated.

[0016] In this embodiment of the application, dividing the selected region of interest into at least two sub-regions based on the feature information of the sample surface includes:

[0017] Analyze the feature information of the selected region of interest surface;

[0018] Regions within the region of interest whose feature information all satisfy the same threshold are grouped into the same sub-region; wherein...

[0019] The sub-region is a continuous portion of the region of interest.

[0020] In this embodiment of the application, the method of configuring corresponding focusing and astigmatism adjustment for each sub-region includes:

[0021] Determine the feature information of each sub-region;

[0022] Based on the aforementioned feature information, a corresponding focusing method and an astigmatism adjustment method are configured for each sub-region.

[0023] In this embodiment of the application, the focusing method includes, but is not limited to, one or more of the following:

[0024] Manual Focusing using Stake Point Interpolation;

[0025] Autofocus (AF);

[0026] The methods for adjusting astigmatism include, but are not limited to, one or more of the following:

[0027] Manual adjustment of image dispersion using pile-point interpolation method (I StigXY);

[0028] Automatic image astigmatism adjustment (ASC).

[0029] In this embodiment of the application, when the region of interest is divided into two sub-regions, a first sub-region and a second sub-region, the step of taking line-by-line images of the entire region of interest based on the focusing and astigmatism adjustment method includes:

[0030] For the region of interest, images are taken row by row starting from the preset first row. If the area to be photographed is determined to be the first sub-region, the focusing mode and astigmatism adjustment mode corresponding to the first sub-region are called for photographing. If the area to be photographed is determined to be the second sub-region, the focusing mode and astigmatism adjustment mode corresponding to the second sub-region are called for photographing.

[0031] This application also provides a focusing control device, which is applied to a scanning electron microscope and includes:

[0032] The region division unit is used to divide the selected region of interest into at least two sub-regions based on the feature information of the sample surface.

[0033] The configuration unit is used to configure the corresponding focusing and astigmatism adjustment methods for each sub-region.

[0034] The image acquisition unit is used to capture the entire region of interest line by line based on the focusing and astigmatism adjustment method to obtain the corresponding image.

[0035] This application also provides a scanning electron microscope, including:

[0036] The first processor is used to divide the selected region of interest into at least two sub-regions based on the feature information of the sample surface; and to configure the corresponding focusing and astigmatism adjustment methods for each sub-region.

[0037] An image processor is used to capture the entire region of interest line by line based on the focusing and astigmatism adjustment methods to obtain the corresponding image.

[0038] This application also provides a scanning electron microscope, including: a first processor and a first memory for storing a computer program capable of running on the processor.

[0039] Wherein, when the first processor is used to run the computer program, it executes the steps of the above method.

[0040] This application also provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the above-described method.

[0041] The focusing control method, apparatus, scanning electron microscope, and storage medium provided in this application divide a selected region of interest into at least two sub-regions based on the feature information of the sample surface; configures corresponding focusing and astigmatism adjustment methods for each sub-region; and performs line-by-line imaging of the entire region of interest based on the focusing and astigmatism adjustment methods to obtain corresponding images. This application divides the selected region of interest into multiple sub-regions based on the feature information of the sample surface and configures corresponding focusing and astigmatism adjustment methods for each sub-region, enabling the imaging needs of different feature areas to be met during large-area scanning imaging, thus ensuring that the entire area can obtain a clearly focused image and reducing the need for subsequent re-imaging. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the focusing control method described in the embodiments of this application;

[0043] Figure 2This is a schematic diagram of the 4*4 image overlapping and stitching described in the embodiments of this application;

[0044] Figure 3 This is a schematic diagram of the region of interest partitioning structure described in an embodiment of this application;

[0045] Figure 4 This is a schematic diagram of the focusing control device described in an embodiment of this application;

[0046] Figure 5 This is a schematic diagram of the scanning electron microscope structure described in the embodiments of this application. Detailed Implementation

[0047] The present application will now be described in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. The present application will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] Example 1

[0049] This application provides a focusing control method, such as... Figure 1 As shown, the method includes:

[0050] Step 101: Divide the selected region of interest into at least two sub-regions based on the feature information of the sample surface;

[0051] Step 102: Configure the corresponding focusing and astigmatism adjustment methods for each sub-region;

[0052] Step 103: Based on the focusing and astigmatism adjustment method, take a line-by-line shot of the entire region of interest to obtain the corresponding image.

[0053] In practical applications, the embodiments of this application can select a region of interest (ROI) on the sample based on the sample analysis requirements. This region can also be called a large area, which is the area that needs to be photographed and observed as a whole.

[0054] It is understood that large-area automated imaging involves automatically scanning and imaging the entire Region of Interest (ROI) at extremely high resolution (small area and high pixel resolution) over a large area to obtain an ultra-high resolution panoramic mosaic of the entire ROI. The panoramic mosaic is composed of several small-area, high-pixel-resolution images. During shooting, the size of the overlap area between images can be set (the overlap area includes the X and Y directions; the default overlap area size is 15%, which is 15% of the image area. For example, an image with 8192*8192 pixels and a pixel size of 4nm has an overlap area width of 1228.8 pixels, which translates to a length of 4.9152um). Subsequent stitching is performed based on the features within the overlap area of ​​each image. Figure 2 The image shown is a schematic diagram of 4x4 image overlap stitching.

[0055] In this embodiment of the application, the feature information of the surface of the sample to be tested includes, but is not limited to, one or more of the following:

[0056] high;

[0057] The height difference between adjacent areas;

[0058] Surface roughness;

[0059] The number of sample features included;

[0060] The level of electron beam irradiation that can be tolerated.

[0061] In this embodiment of the application, dividing the selected region of interest into at least two sub-regions based on the feature information of the sample surface includes:

[0062] Analyze the feature information of the selected region of interest surface;

[0063] Regions within the region of interest whose feature information all satisfy the same threshold are grouped into the same sub-region; wherein...

[0064] The sub-region is a continuous portion of the region of interest.

[0065] In practical applications, such as Figure 3 As shown, in this embodiment of the application, region ① is selected as the region of interest, from... Figure 3It can be seen that the region includes three sub-regions with different feature information. The sample surface within sub-region ② has undulating surfaces (relatively rough) and a height difference with the samples in the surrounding adjacent regions. The sample within sub-region ③ is relatively flat (very smooth), but there is still a height difference with the samples in the surrounding adjacent regions. Therefore, in this embodiment, the region of interest ① can be divided into three sub-regions: sub-region ②, sub-region ③, and the remaining portion of region of interest ① excluding sub-regions ② and ③.

[0066] In this embodiment of the application, the method of configuring corresponding focusing and astigmatism adjustment for each sub-region includes:

[0067] Determine the feature information of each sub-region;

[0068] Based on the aforementioned feature information, a corresponding focusing method and an astigmatism adjustment method are configured for each sub-region.

[0069] Here, corresponding Figure 3 The three sub-regions shown can be configured as follows: for sub-region ②, the focus mode can be set to IFocus, and the astigmatism adjustment mode can be set to I StigXY; for sub-region ③, the focus mode can be set to I Focus, and the astigmatism adjustment mode can be set to I StigXY; for the remaining part of region of interest ① excluding sub-regions ② and ③, the focus mode can be set to AF, and the astigmatism adjustment mode can be set to ASC.

[0070] In this embodiment of the application, the focusing method includes, but is not limited to, one or more of the following:

[0071] Manual Focusing using Stake Point Interpolation;

[0072] Autofocus (AF);

[0073] The methods for adjusting astigmatism include, but are not limited to, one or more of the following:

[0074] Manual adjustment of image dispersion using pile-point interpolation method (I StigXY);

[0075] Automatic image astigmatism adjustment (ASC).

[0076] In this embodiment, the manual focusing method using the stake point interpolation requires the operator to insert 4*4 manually focused points (the number can be increased or decreased depending on the size of the ROI) in the region of interest (ROI). After calculation by the algorithm, the corresponding focus and astigmatism values ​​are applied to each image. In subsequent shooting processes, no further focusing operation is required for each image. This method is suitable for samples with few features, and / or with a small height difference, and / or samples that are not resistant to electron beam irradiation.

[0077] The manual astigmatism adjustment method using stake point interpolation (StigXY) requires the operator to insert manually adjusted astigmatism points in the region of interest (ROI). After calculation, the algorithm applies the corresponding focus and astigmatism values ​​to each image. This method is suitable for samples with few features, and / or slight height differences, and / or samples that are not resistant to electron beam irradiation.

[0078] The autofocus (AF) method automatically identifies features based on real-time acquired image features to find a clear focal point. The operator can set the focus to be applied once every 5 images (the number of focus times can be adjusted according to the shooting effect). This method is suitable for samples with many features and smooth surfaces.

[0079] The automatic astigmatism correction (ASC) automatically identifies features based on real-time acquired image features and finds a clear astigmatism value. The operator can set the astigmatism correction to be performed once every 5 images (the number of astigmatism corrections can be adjusted according to the shooting effect). This method is suitable for samples with many features and flat surfaces.

[0080] In this embodiment of the application, when the region of interest is divided into two sub-regions, a first sub-region and a second sub-region, the step of taking line-by-line images of the entire region of interest based on the focusing and astigmatism adjustment method includes:

[0081] For the region of interest, images are taken row by row starting from the preset first row. If the area to be photographed is determined to be the first sub-region, the focusing mode and astigmatism adjustment mode corresponding to the first sub-region are called for photographing. If the area to be photographed is determined to be the second sub-region, the focusing mode and astigmatism adjustment mode corresponding to the second sub-region are called for photographing.

[0082] In practical application of this embodiment, after determining the storage path of the sample image, an automatic large-area shooting operation can be started to capture the region of interest line by line. During the shooting process, the area being shot is identified. If the area being shot is a first sub-region, the focusing mode and astigmatism adjustment mode corresponding to the first sub-region are automatically called for shooting; if the area being shot is a second sub-region, the focusing mode and astigmatism adjustment mode corresponding to the second sub-region are automatically called for shooting, and finally the sample image of the entire region of interest is obtained.

[0083] This application embodiment divides the selected region of interest into multiple sub-regions based on the feature information of the sample surface, and configures a corresponding focusing and astigmatism adjustment mode for each sub-region. This allows the imaging requirements of different feature regions to be met when scanning and imaging a large area, so that the entire area can obtain a clear image, thereby reducing the work of re-shooting in the later stage.

[0084] Example 2

[0085] To implement the method of the embodiments of this application, the embodiments of this application also provide a focusing control device, such as... Figure 4 As shown, the device is used in a scanning electron microscope and includes:

[0086] The region division unit 401 is used to divide the selected region of interest into at least two sub-regions based on the feature information of the surface of the sample to be tested;

[0087] Configuration unit 402 is used to configure the corresponding focusing and astigmatism adjustment methods for each sub-region;

[0088] The image acquisition unit 403 is used to take a line-by-line picture of the entire region of interest based on the focusing and astigmatism adjustment method to obtain the corresponding image.

[0089] In this embodiment of the application, the feature information of the surface of the sample to be tested includes, but is not limited to, one or more of the following:

[0090] high;

[0091] The height difference between adjacent areas;

[0092] Surface roughness;

[0093] The number of sample features included;

[0094] The level of electron beam irradiation that can be tolerated.

[0095] In this embodiment of the application, the region division unit 401 divides the selected region of interest into at least two sub-regions based on the feature information of the surface of the sample to be tested, including:

[0096] Analyze the feature information of the selected region of interest surface;

[0097] Regions within the region of interest whose feature information all satisfy the same threshold are grouped into the same sub-region; wherein...

[0098] The sub-region is a continuous portion of the region of interest.

[0099] In this embodiment of the application, the configuration unit 402 configures corresponding focusing and astigmatism adjustment methods for each sub-region, including:

[0100] Determine the feature information of each sub-region;

[0101] Based on the aforementioned feature information, a corresponding focusing method and an astigmatism adjustment method are configured for each sub-region.

[0102] In this embodiment of the application, the focusing method includes, but is not limited to, one or more of the following:

[0103] Manual Focusing using Stake Point Interpolation;

[0104] Autofocus (AF);

[0105] The methods for adjusting astigmatism include, but are not limited to, one or more of the following:

[0106] Manual adjustment of image dispersion using pile-point interpolation method (I StigXY);

[0107] Automatic image astigmatism adjustment (ASC).

[0108] In this embodiment of the application, when the region of interest is divided into two sub-regions, a first sub-region and a second sub-region, the image acquisition unit 403 performs line-by-line imaging of the entire region of interest based on the focusing and astigmatism adjustment method, including:

[0109] For the region of interest, images are taken row by row starting from the preset first row. If the area to be photographed is determined to be the first sub-region, the focusing mode and astigmatism adjustment mode corresponding to the first sub-region are called for photographing. If the area to be photographed is determined to be the second sub-region, the focusing mode and astigmatism adjustment mode corresponding to the second sub-region are called for photographing.

[0110] In practical applications, the region division unit 401 and the configuration unit 402 can be implemented by the processor in the focusing control device; the image acquisition unit 403 can be implemented by the imaging device in the focusing control device.

[0111] Example 3

[0112] To implement the method of the embodiments of this application, a hardware implementation based on the above-described program modules is provided. Furthermore, to implement the method of the embodiments of this application, a scanning electron microscope is also provided, such as... Figure 5 As shown, the scanning electron microscope 500 includes:

[0113] The image processor 501 is capable of acquiring and / or processing sample images.

[0114] The first processor 502 is connected to the image processor 501 to enable information interaction with the image processor and / or other modules in the scanning electron microscope, and to execute the methods provided by one or more of the above-mentioned technical solutions of the scanning electron microscope when running a computer program;

[0115] The computer program is stored in the first memory 503.

[0116] Specifically, the first processor 502 is used to divide the selected region of interest into at least two sub-regions based on the feature information of the surface of the sample to be tested; and to configure a corresponding focusing and astigmatism adjustment mode for each sub-region.

[0117] The image processor 501 is used to capture the entire region of interest line by line based on the focusing and astigmatism adjustment method to obtain the corresponding image.

[0118] In this embodiment of the application, the feature information of the surface of the sample to be tested includes, but is not limited to, one or more of the following:

[0119] high;

[0120] The height difference between adjacent areas;

[0121] Surface roughness;

[0122] The number of sample features included;

[0123] The level of electron beam irradiation that can be tolerated.

[0124] In this embodiment of the application, the first processor 502 divides the selected region of interest into at least two sub-regions based on the feature information of the surface of the sample to be tested, including:

[0125] Analyze the feature information of the selected region of interest surface;

[0126] Regions within the region of interest whose feature information all satisfy the same threshold are grouped into the same sub-region; wherein...

[0127] The sub-region is a continuous portion of the region of interest.

[0128] In this embodiment of the application, the first processor 502 configures corresponding focusing and astigmatism adjustment methods for each sub-region, including:

[0129] Determine the feature information of each sub-region;

[0130] Based on the aforementioned feature information, a corresponding focusing method and an astigmatism adjustment method are configured for each sub-region.

[0131] In this embodiment of the application, the focusing method includes, but is not limited to, one or more of the following:

[0132] Manual Focusing using Stake Point Interpolation;

[0133] Autofocus (AF);

[0134] The methods for adjusting astigmatism include, but are not limited to, one or more of the following:

[0135] Manual adjustment of image dispersion using pile-point interpolation method (I StigXY);

[0136] Automatic image astigmatism adjustment (ASC).

[0137] In this embodiment of the application, when the region of interest is divided into two sub-regions, a first sub-region and a second sub-region, the image processor 501 performs line-by-line imaging of the entire region of interest based on the focusing and astigmatism adjustment method, including:

[0138] For the region of interest, images are taken row by row starting from the preset first row. If the area to be photographed is determined to be the first sub-region, the focusing mode and astigmatism adjustment mode corresponding to the first sub-region are called for photographing. If the area to be photographed is determined to be the second sub-region, the focusing mode and astigmatism adjustment mode corresponding to the second sub-region are called for photographing.

[0139] It should be noted that the specific processing procedures of the image processor 501 and the first processor 502 can be understood by referring to the above method, and will not be repeated here.

[0140] Of course, in practical applications, the various components in the scanning electron microscope 500 are coupled together via a bus system 504. It can be understood that the bus system 504 is used to achieve communication between these components. In addition to a data bus, the bus system 504 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 5 The general designated all buses as Bus System 504.

[0141] The first memory 503 in this embodiment is used to store various types of data to support the operation of the scanning electron microscope 500. Examples of such data include any computer program used to operate on the scanning electron microscope 500.

[0142] The methods disclosed in the embodiments of this application can be applied to the first processor 502, or implemented by the first processor 502. The first processor 502 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware or by instructions in the form of software in the first processor 502. The first processor 502 may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The first processor 502 can implement or execute the methods, steps and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the methods disclosed in the embodiments of this application can be directly reflected as being executed by a hardware decoding processor, or being executed by a combination of hardware and software modules in the decoding processor. The software modules may be located in a storage medium, which is located in the first memory 503. The first processor 502 reads the information in the first memory 503 and completes the steps of the aforementioned method in combination with its hardware.

[0143] In an exemplary embodiment, the scanning electron microscope 500 may be implemented by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components to perform the aforementioned methods.

[0144] In an exemplary embodiment, this application also provides a storage medium, namely a computer storage medium, specifically a computer-readable storage medium, such as a first memory 503 storing a computer program. This computer program can be executed by the first processor 502 of the scanning electron microscope 500 to complete the steps described in the aforementioned scanning electron microscope method. The computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disc, or CD-ROM.

[0145] It should be noted that terms such as "first" and "second" are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0146] Furthermore, the technical solutions described in the embodiments of this application can be combined arbitrarily without conflict.

[0147] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application.

Claims

1. A focus control method characterized by, The method is applied to a scanning electron microscope, and the method comprises: dividing a selected region of interest into at least two sub-regions based on characteristic information of a surface of a sample to be measured; configuring a corresponding focusing and stigmation mode for each sub-region respectively; performing line-by-line shooting on the region of interest as a whole based on the focusing and stigmation mode, and obtaining a corresponding image, comprising: starting from a preset first line, performing line-by-line shooting on the region of interest, determining a region to be shot, and calling the focusing mode and the stigmation mode corresponding to the region to be shot to perform shooting; the characteristic information of the surface of the sample to be measured comprises one or more of the following: height; height difference between adjacent regions; roughness of the surface; number of sample features contained; degree of electron beam irradiation that can be tolerated; the focusing mode comprises any one of the following: manual focusing by interpolation method (IFocus); automatic focusing (AF); the stigmation mode comprises any one of the following: manual stigmation by interpolation method (IStigXY); automatic stigmation (ASC).

2. The method of claim 1, wherein, The method is applied to a scanning electron microscope, and the method comprises: dividing a selected region of interest into at least two sub-regions based on characteristic information of a surface of a sample to be measured; analyzing the characteristic information of the surface of the selected region of interest; dividing a part of the region of interest in which the characteristic information meets the same threshold into the same sub-region; wherein 3. The method of claim 1, wherein, the sub-region is a continuous part of the region of interest. The method is applied to a scanning electron microscope, and the method comprises: determining the characteristic information of each sub-region; 4. The method of claim 1, wherein, configuring a corresponding focusing mode and stigmation mode for each sub-region based on the characteristic information. In the case where the region of interest is divided into two sub-regions of a first sub-region and a second sub-region, the line-by-line shooting on the region of interest as a whole based on the focusing and stigmation mode comprises:

5. A focus control device characterized by comprising: starting from a preset first line, performing line-by-line shooting on the region of interest, determining that the region to be shot is the first sub-region, calling the focusing mode and the stigmation mode corresponding to the first sub-region to perform shooting, and determining that the region to be shot is the second sub-region, calling the focusing mode and the stigmation mode corresponding to the second sub-region to perform shooting. The device is applied to a scanning electron microscope, and the device comprises: a region division unit configured to divide a selected region of interest into at least two sub-regions based on characteristic information of a surface of a sample to be measured; a configuration unit configured to configure a corresponding focusing and stigmation mode for each sub-region respectively; an image acquisition unit configured to perform line-by-line shooting on the region of interest as a whole based on the focusing and stigmation mode, and obtain a corresponding image, comprising: starting from a preset first line, performing line-by-line shooting on the region of interest, determining a region to be shot, and calling the focusing mode and the stigmation mode corresponding to the region to be shot to perform shooting; the characteristic information of the surface of the sample to be measured comprises one or more of the following: height; height difference between adjacent regions; roughness of the surface; number of sample features contained; degree of electron beam irradiation that can be tolerated; the focusing mode comprises any one of the following: manual focusing by interpolation method (IFocus); automatic focusing (AF); the stigmation mode comprises any one of the following: manual stigmation by interpolation method (IStigXY); automatic stigmation (ASC). The focusing mode includes any one of the following: Pole interpolation method manual focusing IFocus; Automatic focusing AF; The astigmatism adjustment mode includes any one of the following: Pole interpolation method manual astigmatism adjustment IStigXY; Automatic astigmatism adjustment ASC.

6. A scanning electron microscope, characterized by Comprise: The first processor is used for dividing the selected region of interest into at least two sub-regions based on the feature information of the surface of the sample to be measured; for each sub-region, the corresponding focusing and astigmatism adjustment mode is configured respectively; Image processor, for shooting each row of the region of interest as a whole based on the focusing and astigmatism adjustment mode, obtaining the corresponding image, comprising: for the region of interest, starting from the first row of the preset, shooting each row, determining the region to be shot, calling the focusing mode and the astigmatism adjustment mode corresponding to the region to be shot for shooting; The feature information of the surface of the sample to be measured includes one or more of the following: Height; The height difference between adjacent regions; The roughness of the surface; The number of sample features contained; The degree of electron beam irradiation that can be tolerated; The focusing mode includes any one of the following: Pole interpolation method manual focusing IFocus; Automatic focusing AF; The astigmatism adjustment mode includes any one of the following: Pole interpolation method manual astigmatism adjustment IStigXY; Automatic astigmatism adjustment ASC.

7. A scanning electron microscope, characterized by Comprise: The first processor and the first memory for storing computer programs capable of running on the processor, Wherein, the first processor is used for running the computer program, executing the steps of the method of any one of claims 1 to 4.

8. A storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to realize the steps of the method of any one of claims 1 to 4.

Images