JP5389766B2 - Scanning electron microscope - Google Patents

Description

  The present invention relates to a scanning electron microscope.

  A scanning electron microscope scans an observation site of a sample with a charged particle beam, and generates a two-dimensional observation image using electrons emitted from the sample. In general, a sample is scanned linearly using a charged particle beam, and a vertical synchronization signal (V-Sync) and a horizontal synchronization signal (H-Sync) are superimposed on the obtained detection signal to obtain a two-dimensional image on the sample. An image is generated after the coordinates are specified.

  The following Patent Document 1 describes an example in which an observation image is generated using a raster scan that scans a sample in a straight line in the same direction.

  On the other hand, in recent years, high precision and high speed (decrease in the amount of beam irradiation per unit area) have been demanded due to the demand for miniaturization of measurement objects and reduction of damage due to electron beams of observation objects. In order to meet these demands, not only the raster scan described in the above-mentioned Patent Document 1, but also a scan from the periphery of the observation region toward the center is performed to eliminate the adverse effects due to sample charging, etc. It is necessary to use a technique such as performing a partial scan that scans only a certain observation target.

  However, the method using the vertical synchronizing signal and the horizontal synchronizing signal described above can deal only with raster scanning. Therefore, in order to support various scan types, image data and the two-dimensional coordinates of each pixel are temporarily stored in a memory (SRAM: Static Random Access Memory, etc.) that can be accessed at high speed, and a scan for one frame is performed. A method of generating a two-dimensional image using a vertical synchronization signal or a horizontal synchronization signal at the time when is finished.

JP-A-9-180667

  In the above-described method for temporarily storing image data and its two-dimensional coordinates on the memory, it is necessary to store data for representing the two-dimensional coordinates of each pixel on the memory in addition to the image data itself. Therefore, the required memory capacity becomes very large.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a scanning electron microscope that can reduce the data volume necessary for generating an observation image.

  The scanning electron microscope according to the present invention scans a sample in one or more straight lines, and sets information for specifying the start position and end position of the scan line as address information indicating the scan position on the sample. To the detection signal.

  According to the scanning electron microscope of the present invention, the address information is given not for each pixel but for each scanning line, so that the data capacity necessary for storing the address information on the memory can be reduced.

1 is a configuration diagram of a scanning electron microscope 100 according to Embodiment 1. FIG. 3 is a diagram showing an internal configuration of an address assigning unit 106. FIG. It is a figure which shows one example of the address allocation signal 110. FIG. It is a figure which shows the structure of the scanning line pixel data 130 which the address provision part 106 outputs. It is a figure explaining the procedure in which the address provision part 106 processes the address allocation signal 110. FIG. It is a figure which shows the data example of the scanning line pixel data 130 in the case of scanning a sample spirally toward a center from a peripheral part. It is a figure which shows the deflector structure of the scanning electron microscope 100 which concerns on Embodiment 3. FIG. It is a figure which shows the structure of the scanning line pixel data 130 in Embodiment 3. FIG. It is a figure which shows the structural example of the scanning line pixel data 130 which the scanning electron microscope 100 which concerns on Embodiment 4 produces | generates. It is a figure which shows a mode that the scanning electron microscope 100 scans the some scanning range 201-203 on a sample. FIG. 10 is a diagram illustrating a configuration of scanning line pixel data in Embodiment 5. It is a figure explaining the method of producing | generating an observation image using the raster scan described in patent document 1. FIG. It is a figure explaining the method which scans a sample using scan types other than a raster scan, and produces | generates an observation image. It is a figure explaining the method of providing the two-dimensional coordinate on a sample for every pixel data, and storing on a memory.

<Conventional image data generation method>
Hereinafter, for comparison with the present invention, first, a conventional method for generating image data will be described. Thereafter, an image data generation method employed by the scanning electron microscope according to the present invention will be described.

  FIG. 12 is a diagram illustrating a method for generating an observation image using a raster scan described in Patent Document 1. In this document, a two-dimensional image is generated by superimposing a vertical synchronization signal and a horizontal synchronization signal on a one-dimensional luminance signal obtained from a detector.

  FIG. 13 is a diagram for explaining a method of scanning a sample using a scan type other than the raster scan and generating an observation image. In the method shown in this figure, a sample is scanned in a spiral shape, and image data of each pixel and a two-dimensional coordinate are paired and temporarily stored in a memory. Thereafter, when scanning for one frame is completed, a two-dimensional image is generated using a vertical synchronization signal or a horizontal synchronization signal.

  In general, in a method of storing image data and two-dimensional coordinates in a memory, the X coordinate and the Y coordinate are connected to form a one-dimensional column, which is used as an address on the memory, and the image data is stored at the address. In this method, since an address is assigned independently for each pixel data, it is necessary to access the memory in units of pixels, and random access is essential. That is, the memory used in this method requires a random access speed that is higher than the speed at which pixel display is updated. This random access rate is given by:

  For example, when one frame is acquired every 20 ms, a random access speed of 200 Gbps or more is required as follows. For this reason, a memory device such as a DRAM (Dynamic Random Access Memory) having a low bit unit price cannot be used, and a more expensive SRAM must be used.

  FIG. 14 is a diagram for explaining a method of storing two-dimensional coordinates on a sample for each pixel data and storing them on a memory. When the scanning speed is 30 frames / s or more, the image rewriting speed that can be identified by humans is exceeded. Therefore, it is not necessary to update the screen display for each image. In this case, the necessity of strictly associating the vertical synchronization signal and horizontal synchronization signal of the display device with the pixel data is reduced.

  Therefore, in the method shown in FIG. 14, the method shown in FIG. 2 is further developed, and two-dimensional coordinates on the sample are assigned to each pixel data and stored in the memory. However, when this method is used, two-dimensional coordinate data is stored in the memory in addition to the pixel data, so that the memory capacity required for generating the observation image increases. This memory capacity can be obtained by the following equation.

That is, when this method is used, an extra data amount of at least log ₂ (m · n) is required for each pixel data. Furthermore, since a general computer processes data in units of 8 bits (1 byte), the memory capacity required to store pixel data is a multiple of 8 bits. For this reason, when the amount of data of each pixel data and its two-dimensional coordinates is not a multiple of 8 bits, an extra free area is generated in a portion that cannot be divided by 8, and a larger amount of data is required as a whole. As an example, the data capacity required for storing image data of 16384 pixels in the vertical and horizontal directions is shown below.

<Embodiment 1>
FIG. 1 is a configuration diagram of a scanning electron microscope 100 according to Embodiment 1 of the present invention. The scanning electron microscope 100 includes an irradiation unit 101, a scan engine 102, an X deflector 103, a Y deflector 104, a detector 105, an address assigning unit 106, and an image processing unit 107.

  The irradiation unit 101 irradiates a sample to be observed with a charged particle beam. Examples of the charged particle beam include an electron beam and an ion beam. The X deflector 103 and the Y deflector 104 deflect the charged particle beam in two orthogonal directions (here, the X axis and the Y axis) on the sample, respectively. The scan engine 102 deflects the charged particle beam using the X deflector 103 and the Y deflector 104, and controls the irradiation position of the charged particle beam on the sample. The detector 105 detects electrons generated by irradiating a sample with a charged particle beam, converts the electrons into a detection signal including luminance information, and outputs the detection signal to the address assigning unit 106.

  The address assigning unit 106 receives an address assignment signal 110 described later with reference to FIG. 3 from the scan engine 102, and generates address information indicating two-dimensional coordinates on the sample irradiated with the charged particle beam. The address assigning unit 106 assigns address information to the detection signal 120 received from the detector 105, and outputs the address information to the image processing unit 107 as scanning line pixel data 130.

  The image processing unit 107 converts the luminance information included in the detection signal 120 into a two-dimensional image using the two-dimensional coordinates (address information) included in the scanning line pixel data 130 received from the address assigning unit 106, and An observation image is generated.

  The “deflection control unit” in the present invention corresponds to the scan engine 102. The address assigning unit 106 and the image processing unit 107 can be configured using hardware such as a circuit device that realizes these functions, or a computing device such as a CPU (Central Processing Unit) and software that defines the operation thereof. Can also be used.

  FIG. 2 is a diagram illustrating an internal configuration of the address assigning unit 106. The address assigning unit 106 includes an address assigning internal block 1061 and a data temporary buffer 1062. The address assignment internal block 1061 receives the address assignment signal 110 and executes a processing flow described later with reference to FIG. The temporary data buffer 1062 is a memory device that functions as a buffer that temporarily stores address information being processed. The address assignment signal 110 includes a frame number 111, an X deflector signal 112, a Y deflector signal 113, and a blank signal 114.

  FIG. 3 is a diagram illustrating an example of the address assignment signal 110. The scan engine 102 turns off the blank signal 114 in the section in which the charged particle beam is deflected using the X deflector 103 or the Y deflector 104 to scan the sample. In other sections, the blank signal 114 is turned on.

  The scan engine 102 changes the value of the X deflector signal 112 when scanning the sample in the X axis direction using the X deflector 103, and uses the Y deflector 104 to scan the sample in the Y axis direction. When scanning, the value of the Y deflector signal 113 is changed.

  That is, the direction in which the scan engine 102 scans the sample is switched at the boundary between the X deflector signal 112 and the Y deflector signal 113. In the section where the blank signal 114 is ON, the sample is not scanned.

  FIG. 4 is a diagram illustrating a configuration of the scanning line pixel data 130 output from the address assigning unit 106. The scanning line pixel data 130 is data that holds pixel data obtained from one scanning line when a sample is scanned using a charged particle beam. The scanning line pixel data 130 includes a frame number 131, a Y deflection start point 132, an X deflection start point 133, a Y movement amount 134, an X movement amount 135, and pixel data 136.

  The frame number 131 holds the time series number of the observation image of the sample. An observation image of the sample at a certain point in time is not obtained with only one scanning line, but one observation image is obtained by combining pixel data obtained from a plurality of scanning lines. Therefore, in order to indicate at which point in time each piece of scanning line pixel data 130 holds pixel data, this number is held.

  The Y deflection start point 132 and the X deflection start point 133 are data describing the start points in the X and Y axis directions of the scanning line in which the scanning line pixel data 130 holds the pixel data as two-dimensional coordinates of the scanning range on the sample. .

  The Y movement amount 134 and the X movement amount 135 are data indicating the amount by which the scanning position of the scanning line in which the scanning line pixel data 130 holds the pixel data has moved from each starting point. Instead of the movement amount, the end point position in each axial direction may be held. That is, information other than the movement amount may be used as long as the information can identify at which position the scanning line ends.

  The pixel data 136 is data that holds pixel data on a scanning line in which the scanning line pixel data 130 holds pixel data as a luminance value distribution. In the pixel data 136, data obtained by replacing the detection signal 120 obtained from each scanning position on the scanning line with a luminance value is arranged in the scanning direction. That is, the pixel data 136 is obtained by reconstructing the detection signal 120 as pixel data for the purpose of image processing on the computer, and is substantially equivalent to the detection signal 120.

FIG. 5 is a diagram illustrating a procedure in which the address assignment unit 106 processes the address assignment signal 110. Hereinafter, the processing procedure of the address assignment signal 110 will be described with reference to FIG.
(FIG. 5: Step S500)
The address assignment unit 106 executes this operation flow for each scanning line when the scan engine 102 scans the sample.
(FIG. 5: Step S501)
The address assignment unit 106 determines whether or not the blank signal 114 is ON. If it is ON, it is determined that the scan engine 102 is not executing scanning, and this step is continued. If it is OFF, it is determined that the scan engine 102 is executing scanning, and the process proceeds to step S502.

(FIG. 5: Step S502)
The address assigning unit 106 determines whether or not the X deflector signal 112 or the Y deflector signal 113 is changed. If the X deflector signal 112 has changed, the process proceeds to step S503, and if the Y deflector signal 113 has changed, the process proceeds to step S506. If none of the deflector signals have changed, it is treated as an error.
(FIG. 5: Step S503)
The address assigning unit 106 determines that the scan engine 102 is scanning the charged particle beam in the X-axis direction because the blank signal 114 is OFF, the X deflector signal 112 is changed, and the Y deflector signal 113 is not changed. To do. The address assigning unit 106 stores the detection signal 120 from the detector 105 in the data temporary buffer 1062 as a detection signal in the X-axis direction, that is, pixel data 136 in the X-axis direction.
(FIG. 5: Step S503: Supplement)
The capacity of the data temporary buffer 1062 needs to be larger than the maximum linear distance of the required maximum image size, that is, the value obtained by multiplying the maximum number of pixels on the X coordinate side or the Y coordinate side by the number of pixel bits.

(FIG. 5: Step S504)
The address assigning unit 106 counts the amount of movement of the scanning position on the sample in the X-axis direction, and stores it in the data temporary buffer 1062 as the X movement amount 135. The start position of the scanning line on the sample is stored in the data temporary buffer 1062 as the X deflection start point 133.
(FIG. 5: Step S505)
The address assigning unit 106 determines whether the Y deflector signal 113 starts to change or whether the blank signal 114 is ON. That is, it is determined whether the boundary portion between the X signal change block and the Y signal change block in FIG. 3 has been reached or the scanning is stopped. If these are the case, the process proceeds to step S509. If not, the process returns to step S503 and the same processing is repeated.

(FIG. 5: Steps S506 to S508)
The address assigning unit 106 performs the same processing as steps S503 to S505 in the Y-axis direction as well. However, the signals and data fields to be used are the Y deflector signal 113, the Y deflection start point 132, and the Y movement amount 134, which are different from steps S503 to S505.
(FIG. 5: Step S509)
The address assigning unit 106 combines the frame number 131, the Y deflection start point 132, the X deflection start point 133, the Y movement amount 134, and the X movement amount 135 stored in the data temporary buffer 1062, and shapes the address information shown in FIG. .
(FIG. 5: Steps S510 to S511)
The address assigning unit 106 assigns address information to the pixel data 136 corresponding to the scanning line, and shapes it as the scanning line pixel data 130 (S510). The address assignment unit 106 outputs the scanning line pixel data 130 to the image processing unit 107 (S511).

  FIG. 6 is a diagram illustrating a data example of the scanning line pixel data 130 when a sample is scanned spirally from the peripheral portion toward the center. Here, an example is shown in which an area having a size of 512 pixels on both the XY axes is scanned.

  The address assigning unit 106 starts the first scan from (Y deflection coordinates, X deflection coordinates) = (0, 0). Since the X deflector signal 112 increases in the direction of the X deflection coordinate 140, the address assigning unit 106 determines in step S502 that scanning in the X axis direction is being performed.

  The address assigning unit 106 increments the value of the X movement amount 135 as the X deflector signal 112 increases. Further, the pixel data 136 is acquired from the detection signal 120 and stored in the data temporary buffer 1062.

  When (Y deflection coordinate, X deflection coordinate) changes from (0,511) to (1,511), the address assigning unit 106 determines in step S505 that scanning in the X-axis direction has ended.

  The address assigning unit 106 generates address information by combining the frame number 131, the Y deflection start point 132, the X deflection start point 133, the Y movement amount 134, and the X movement amount 135. In addition, the scanning line pixel data 130 is generated by combining the absolute value of the X movement amount 135 with the pixel data 136 stored in the data temporary buffer 1062 as the pixel data storage amount. Through the above procedure, the first scanning line pixel data 130 in FIG. 6 is generated.

  The address assigning unit 106 starts the next scan from (Y deflection coordinates, X deflection coordinates) = (1,511). The address assigning unit 106 performs scanning in the same manner as described above. In this case, since the Y deflector signal 113 changes, the address assigning unit 106 performs scanning in the Y-axis direction in step S502. The point to judge is different.

  When (Y deflection coordinate, X deflection coordinate) changes from (511,511) to (511,510), the address assigning unit 106 determines in step S505 that scanning in the Y-axis direction has ended. Similarly, the address assigning unit 106 generates the second scanning line pixel data 130 of FIG.

<Embodiment 1: Summary>
As described above, the scanning electron microscope 100 according to the first embodiment scans a sample using a plurality of linear scanning lines, and specifies the start position and the end position of the scanning line for each scanning line. Information to be applied is given to the pixel data 136 as address information. This address information indicates which position on the sample the scanning line is obtained by scanning. That is, since the coordinate information indicating the scanning position on the sample is not held for each pixel but for each scanning line, the data capacity of the memory device such as the data temporary buffer 1062 required for storing the coordinate information is stored. Can be reduced. Further, since the data string is continuous for each scanning line, it is possible to use a non-volatile memory with a low bit unit price such as a DRAM that secures a data band by burst transfer.

  In the first embodiment, the data amount of the scanning line image data 130 can be obtained by the following calculation formula excluding the frame number 131.

  When the frame number 131 is assigned, the corresponding data length (the number of scanning lines × the data length of the frame number 131) is added in parentheses in the second term of the above formula.

<Embodiment 2>
In the first embodiment, after the scanning of one frame is completed, the scanning line pixel data 130 can be generated twice by scanning again for the same scanning position. In this case, the Y deflection start point 132, the X deflection start point 133, the Y movement amount 134, and the X movement amount 135 have the same values as those of the previously performed scan. Therefore, the frame number 131 may be used to identify at which time point the scanning line pixel data 130 is obtained by scanning.

  Further, even when the scan range in each frame is different, if the frame number 131 is described in the scan line pixel data 130, the scan line pixel data 130 acquired by the number of scans can be identified. be able to. If the scanning line pixel data 130 acquired by the number of scans is known, the scanning line pixel data 130 can be detected from which scan range by comparing with a record of which range the scan was performed at that time. Whether it is obtained can be easily identified.

  Alternatively, the same location on the sample may be scanned a plurality of times in time series, and the observation images obtained in each scan may be superimposed. Thereby, a clear observation image can be obtained. The frame number 131 can also be used to identify at which time point each pixel data is obtained.

  On the other hand, when only a single scan is performed in time series for the same scanning position, the frame number 131 can be omitted. The same applies to the following embodiments.

<Embodiment 3>
FIG. 7 is a diagram showing a deflector configuration of the scanning electron microscope 100 according to the third embodiment of the present invention. In the first embodiment, the configuration in which the charged particle beam is deflected in the XY axis direction by using the X deflector 103 and the Y deflector 104 is exemplified. However, a deflector is newly provided in the axial direction other than the XY axis, so You may make it carry out deflection control of the particle beam. Other configurations are the same as those in the first and second embodiments.

  In FIG. 7, an intermediate shaft deflector 150 is provided in an intermediate axis direction facing an intermediate angle between the X axis direction and the Y axis direction (45 ° in the third embodiment, but not limited thereto). Although an example is shown, the present invention is not limited to this, and a deflector that deflects a charged particle beam in an arbitrary direction can be provided. Further, the number of deflectors and deflection directions can be arbitrarily set.

  FIG. 8 is a diagram showing a configuration of the scanning line pixel data 130 in the third embodiment. As illustrated in FIG. 7, when a deflection axis is provided in an axial direction other than the XY axis direction, it is necessary to hold coordinate information on the sample in the axial direction.

  Therefore, in the third embodiment, in addition to the data configuration described in FIG. 4, the intermediate deflection start point 137 and the intermediate movement amount 138 are newly held in the scanning line pixel data 130. Thereby, the scanning position when the charged particle beam is deflected in the intermediate axis direction can be held in the scanning line pixel data 130.

<Embodiment 4>
In general, the image processing unit 107 of the scanning electron microscope 100 is incorporated in the scanning electron microscope 100, but is not necessarily limited thereto, and image processing is performed at a position away from the main body of the scanning electron microscope 100. It is also possible to arrange the unit 107 so as to transmit and receive the scanning line pixel data 130 via a communication network. According to this embodiment, since a high-performance computer or the like can be used as the image processing unit 107, it is advantageous in that the scanning electron microscope 100 can be configured more flexibly.

  However, since the scanning line pixel data 130 is a large amount of data, the communication network may become a bottleneck, and image processing performance may be reduced. Therefore, in Embodiment 4 of the present invention, the scanning line pixel data 130 is shaped into a format suitable for communication.

  FIG. 9 is a diagram illustrating a configuration example of the scanning line pixel data 130 generated by the scanning electron microscope 100 according to the fourth embodiment. In the first to third embodiments, the configuration in which the scanning line pixel data 130 is generated by combining the frame numbers 131 to 136 for each scanning line is described. However, in the fourth embodiment, a plurality of scanning lines are scanned. The frame number 131 to the pixel data 136 are combined to form one data package. Specifically, for example, frame numbers 131 to pixel data 136 for a plurality of scanning lines may be stored as a set in a field that stores a data body portion such as a payload portion of a data packet.

  According to the data configuration shown in FIG. 9, overhead related to communication such as a header portion of a communication packet can be reduced. Therefore, when scanning line pixel data 130 is transmitted and received via a communication network, from the viewpoint of processing performance. It is advantageous.

<Embodiment 5>
FIG. 10 is a diagram showing how the scanning electron microscope 100 scans a plurality of scanning ranges 201 to 203 on the sample. Since the range in which the deflector of the scanning electron microscope 100 can deflect the charged particle beam is limited, in order to scan the entire observation target region on the sample, scanning for one screen is performed a plurality of times. You may have to. In FIG. 10, this state is indicated by scanning ranges 201 to 203.

  When scanning a new scanning range, the two-dimensional coordinates of the scanning position usually start from the initial value again. At this time, if the scanning line pixel data 130 for which scanning range is acquired can be identified later, the scanning line pixel data 130 in an arbitrary scanning range can be read immediately, which is convenient. Therefore, in the fifth embodiment of the present invention, a scanning range identification number is newly held in the scanning line pixel data 130.

  FIG. 11 is a diagram illustrating a configuration of the scanning line pixel data 130 according to the fifth embodiment. In the fifth embodiment, the scanning line pixel data 130 newly holds a scanning range identification number 139 in addition to the configuration described in FIG. 4 or FIG.

  When the scanning line pixel data 130 is generated, the address assigning unit 106 assigns a scanning range identification number 139 for each scanning range on the sample described by the address information. It is not always necessary to assign the scanning range identification number 139 to each maximum scanning range that the address information can describe. It suffices if the scanning line pixel data 130 acquired for which scanning range can be identified.

  The image processing unit 107 uses the address information included in the scanning line pixel data 130 and the scanning range identification number 139 to generate an observation image of the sample. For example, the scanning line pixel data 130 whose scanning range identification number 139 is 0 to 10 is displayed in order from the left to the right in the first row, and the scanning line pixel data 130 whose scanning range identification number 139 is 11 to 20 is two rows. Display rules such as displaying in order from the left to the right of the eyes can be determined in advance. Thereby, even if the two-dimensional coordinates indicated by the address information are the same, it is possible to easily identify the scanning line pixel data 130 obtained from which scanning range.

  The operator of the scanning electron microscope 100 can also instruct the image processing unit 107 to designate the scanning range identification number 139 and display the observation image in the scanning range on the screen. The image processing unit 107 can acquire the scanning line pixel data 130 having the designated scanning range identification number 139, generate an observation image, and display it on the screen.

  DESCRIPTION OF SYMBOLS 100: Scanning electron microscope, 101: Irradiation part, 102: Scan engine, 103: X deflector, 104: Y deflector, 105: Detector, 106: Address assignment part, 1061: Address assignment internal block, 1062: Data Temporary buffer, 107: Image processing unit, 110: Address assignment signal, 111: Frame number, 112: X deflector signal, 113: Y deflector signal, 114: Blank signal, 120: Detection signal, 130: Scan line pixel data 131: Frame number 132: Y deflection start point 133: X deflection start point 134: Y movement amount 135: X movement amount 136: Pixel data 137: Intermediate deflection start point 138: Intermediate movement amount 139: Scanning Range identification number.

Claims (7)

A deflection controller that controls the direction in which the sample is irradiated with the charged particle beam;
A detector that detects electrons emitted from the sample and converts them into detection signals;
An address assigning unit for assigning address information indicating the correspondence between the detection signal and a scanning position on the sample to the detection signal;
An image processing unit that generates an observation image of the sample using the detection signal and the address information;
With
The deflection control unit
Scanning the sample in one or more lines using the charged particle beam;
The address assigning unit
Information for specifying the start position of the scan line on the sample and information for specifying the end position of the scan line on the sample for each scan line scanned by the deflection controller As information, it gives to the said detection signal obtained with the said scanning line. The scanning electron microscope characterized by the above-mentioned. The address assigning unit
The scanning electron microscope according to claim 1, wherein a frame number indicating a time series number of the observation image is given to the detection signal as the address information. The image processing unit
The scanning electron microscope according to claim 2, wherein a plurality of the observation images acquired in time series for the same portion on the sample are superimposed to generate a single observation image. The deflection control unit
Deflecting the charged particle beam in two orthogonal directions on the sample and in an intermediate axial direction facing the direction between the two axes;
The address assigning unit
For each of two orthogonal axes on the sample and an intermediate axis facing the direction between the two axes, the deflection control unit assigns the address information to the detection signal for each scanning line that scans the sample. The scanning electron microscope according to claim 1, wherein: The address assigning unit
The detection signal and the address information for a plurality of the scanning lines are packaged in one data block and transmitted to the outside of the scanning electron microscope via a network line. Scanning electron microscope. The address assigning unit
The scanning electron microscope according to claim 1, wherein an identification number is assigned to each scanning range on the sample described by the address information, and the identification number is given to the detection signal together with the address information. The image processing unit
Receiving an instruction designating the identification number, obtaining the detection signal and the address information corresponding to the identification number, and generating an observation image of a scanning range on the sample designated by the identification number The scanning electron microscope according to claim 6.

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