JP3948370B2 - Electron beam analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention irradiates a sample with a beam of an electron beam such as a scanning electron microscope (SEM), an electron beam microanalyzer (EPMA), etc., and detects characteristic X-rays, reflected electrons, secondary electrons, etc. generated from the sample. The present invention relates to an electron beam analyzer that performs analysis and morphology observation.
[0002]
[Prior art]
Conventionally, in an electron beam analyzer, in addition to scanning the entire observation visual field as a scanning region, it is also required to designate a scanning region within the observation visual field and scan within the designated scanning region.
[0003]
In response to such a request, for example, a binary counter that counts a reference oscillation clock and a register for setting a scanning end point are provided in an electron beam analyzer, and a configuration that designates a scanning area by this is known. Yes. In order to scan the designated scanning area in this configuration, the number of data points corresponding to the scanning area designated in the register is determined in advance, scanning is started from the scanning start position, and the reference oscillation clock is sequentially counted by the binary counter. When the count value reaches the number of data points set in the register, the scanning is terminated. According to this configuration, the scanning area can be determined by the number of data points.
[0004]
[Problems to be solved by the invention]
In the conventional configuration in which the scanning area is specified using the register and the binary counter, the shape of the scanning area depends on the scanning procedure of the electron beam, and thus there is a problem that the scanning area cannot be formed into an arbitrary shape without flexibility. is there.
[0005]
The electron beam scanning procedure is generally performed by performing line scanning in the x direction while sequentially shifting the position in the y direction. In the electron beam scanning according to this scanning procedure, when a scanning area is designated using a register and a binary counter, the shape of the designated scanning area is a quadrangle, and the scanning area cannot be determined to an arbitrary shape. For example, it is not possible to meet the requirement to specify a scanning region in a curved line within the observation field and obtain a scanning observation image.
[0006]
Designation of the scanning region may be determined by an observer by observing an optical image, or an electron beam irradiation region or a non-irradiation region may be determined based on structural features of the sample. For example, when an insulator is present in the sample, the region where the insulator is present and the observation region cannot be irradiated under the same beam setting conditions. If an insulator region is irradiated with an electron beam under the same high acceleration voltage and high current beam setting conditions as those in the observation region, charge-up occurs and detection becomes difficult, and sufficient analysis results cannot be obtained.
[0007]
In a conventional electron beam analyzer, analysis is performed under different beam setting conditions to obtain a plurality of two-dimensional images, and data processing of these two-dimensional image data results in arbitrarily specifying a scanning region. It is possible. However, in this case, a plurality of scans and data processing of image data are required, so that there is a problem that processing time becomes long and observation in real time is impossible.
[0008]
Therefore, the present invention aims to solve the above-mentioned conventional problems and to specify an electron beam scanning region arbitrarily, and to observe a two-dimensional image of the arbitrarily designated electron beam scanning region in real time. The purpose is to be able to.
[0009]
[Means for Solving the Problems]
The present invention provides an electron beam analyzer that performs sample analysis by two-dimensional scanning of an electron beam, and includes a storage unit that stores region designation data and an electron beam control unit that controls electron beam irradiation. By controlling the electron beam irradiation based on the data, it is possible to scan an arbitrarily designated scanning region.
[0010]
The area designation data includes position data for determining the position in the analysis target area and operation parameters for determining the operation of the electron beam at this position. The electron beam control means sequentially reads the position data and the operation parameter from the storage means, and irradiates or non-irradiates the electron beam to the position determined by the position data based on the operation parameter. Thereby, the arbitrarily designated electron beam scanning region is two-dimensionally scanned, and the acquired two-dimensional image is observed in real time.
[0011]
The operation parameter defines a standby parameter for determining a standby operation in which the electron beam is removed from the irradiation position and in a non-irradiation state, and a return operation for returning the electron beam that has been removed from the sample by the standby operation to the irradiation state. Contains return parameters. The control means starts the standby operation with the standby parameter and ends the standby operation with the return parameter.
[0012]
The standby parameter determines the standby direction of the electron beam with respect to the scanning line, and the control means can control the deflection direction of the electron beam based on the standby direction determined by the standby parameter. In some cases, the electron beam can be moved while avoiding regions that are not desired to be irradiated on the sample.
[0013]
Furthermore, the electron beam analyzer of the present invention includes a setting unit that sets an electron beam scanning region with respect to the analysis target region, and an operation position of a predetermined operation performed in the scanning region based on the scanning region set by the setting unit. Region specifying data generating means for generating position data to be determined and operation parameters for determining the operation content. The storage means stores the position data and operation parameters generated by the area designation data generation means as area designation data.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an example of a command area designated by the electron beam analyzer of the present invention, and FIG. 2 is a diagram for explaining each operation of scanning, retracting, and returning an electron beam with respect to the designated area.
[0015]
In FIG. 1, an analysis target area A indicates an entire area that can be scanned two-dimensionally by the electron beam analyzer, and a hatched portion in the analysis target area A indicates a scanning area B that is scanned by irradiation with an electron beam. A portion in the scanning region B indicates a non-scanning region C where no electron beam is irradiated. In the present invention, the shape of the scanning region B can be arbitrarily determined. The analysis target area A can be represented by a total of 307200 pixels, for example, with 640 points in the x direction and 480 points in the y direction. This number of pixels is an example and can be an arbitrary number. Further, FIG. 1 shows an example in which the non-scanning area C is defined in the scanning area B, but conversely, the scanning area B can be defined in the non-scanning area C.
[0016]
The area designation of the scanning area and the non-scanning area can be performed, for example, by displaying the analysis target area A on the host computer and drawing it on the image. The area designation by drawing can be performed, for example, by curve drawing by mouse dragging.
[0017]
The non-scanning region C can be set, for example, as an insulating region on the sample. The beam setting conditions of the electron beam are different between the portion where the insulator exists and the other portion. If an electron beam with the same beam setting conditions (high acceleration voltage, large current) as that in the scanning area is irradiated to the portion where the insulator exists, the sample will be charged up and detection will be difficult. The beam setting conditions for the electron beam applied to the portion to be irradiated must be a low acceleration voltage and a small current.
[0018]
Therefore, in the electron beam analyzer of the present invention, when the scanning region is scanned, a portion where the insulator exists is designated as the non-scanning region C, and the irradiation of the electron beam is controlled based on this designation, whereby a predetermined region is obtained. Analyze without charging up with electron beam beam setting conditions.
[0019]
FIG. 2 shows electron beam scanning, evacuation, and return operations by the electron beam analyzer of the present invention. 2 sets the same scanning region B and non-scanning region C as in FIG. 1, and two-dimensionally scans the electron beam in the x and y directions on the scanning region B, and the electron beam irradiation direction in the non-scanning region C. Is set to be a non-irradiated state by making the region other than the analysis target region A of the sample. In order to achieve this non-irradiation state, the electron beam is saved and restored at the boundary between the scanning region B and the non-scanning region C. When the electron beam reaches the boundary of the non-scanning region C (XA, XC in FIG. 2) during the scanning of the scanning region B in the x direction ((1), (1) 'in FIG. 2) The electron beam irradiation direction is changed and removed from the scanning line ((2), (2) 'in FIG. 2).
[0020]
In this retracting operation state, when the scanning position of the electron beam reaches the other boundary of the non-scanning region C (XB, XD in FIG. 2), the irradiation direction of the electron beam is returned to the original scanning line by the return operation (FIG. (3), (3) 'in 2). The electron beam returned to the scanning line by the returning operation restarts scanning of the scanning region B ((4), (4) 'in FIG. 2).
[0021]
By repeating the above operation on the boundary line of the non-scanning region C, only the scanning region B except for the non-scanning region C is two-dimensionally scanned even in the non-scanning region C set in an arbitrary shape. Can do. By displaying the detection signal acquired by the two-dimensional scanning as an image signal, a two-dimensional image of the arbitrarily designated electron beam scanning region can be observed in real time.
[0022]
FIG. 3 is a block diagram for explaining the outline of the electron beam analyzer of the present invention. The electron beam analyzer 1 is configured to scan an analysis sample S with an electron beam, a scan generator 2 that generates a counter output as a scanning signal, and an analog signal that performs D / A conversion of the counter output and controls the beam scanning position. A D / A converter 3 for generating the power, a control amplifier / power amplifier 4 for forming a drive current to be supplied to the beam scanning coil, and a beam scanning coil 5 for controlling the irradiation direction of the electron beam.
[0023]
In addition, the electron beam analyzer 1 is configured to acquire a two-dimensional image. The detector 6 detects characteristic X-rays, reflected electrons, secondary electrons, and the like generated from the analysis sample S by scanning the electron beam, and a detector. An amplifier and A / D converter 7 that amplifies the detection signal from signal 6 and converts it into a digital image signal, and an image memory and video D / A converter that stores the acquired image digital data and converts it into a video signal 8, a video capture 9 for capturing a video signal, and an image display means / user interface 13 for displaying the captured image signal.
[0024]
Further, the electron beam analyzer 1 of the present invention is configured to scan an electron beam in an arbitrarily designated scanning region, and an electron beam based on a user interface 13 for designating a region and region designation data designated by the user interface 13. A control CPU / memory 10 that controls the start, stop, and save and return operations of the scan, a preset buffer 11 that stores the start and stop points of the scan, and an electron beam according to a control command that instructs the save and return The beam saving circuit 12 is provided for instructing the control amplifier / power amplifier 4 to perform the beam saving and returning operations.
[0025]
The electron beam analyzer 1 of the present invention first designates a scanning region in order to perform two-dimensional scanning on a scanning region that is arbitrarily designated and display the acquired two-dimensional image.
[0026]
For specifying the scanning area, for example, the image data of the sample is acquired by an optical microscope or the like (not shown) and displayed on the image display means 13, and this display image is observed and scanned into the analysis target area A of the sample. Region B and non-scanning region C are set. This area can be specified by using a video capture function by the user interface 13 such as a mouse provided in the computer, for example.
[0027]
Further, the user interface 13 can set the start point and end point of scanning in the analysis target area A. Note that the scanning area B is set within an area defined by the start and end points of scanning.
[0028]
FIG. 4 is a diagram showing an area designation data format. FIG. 4A shows an example of a data format for area designation, which includes a memory address and memory data, and the area designation data is set for each pixel in the analysis target area.
[0029]
The memory address corresponds to the counter output generated by the scan generator 2, and the memory data is read according to the counter output. Although the number of bits of the memory address depends on the size of the designated area, in FIG. 4A, for example, it is represented by 24 bits A23 to A0 (X = 12 bits, Y = 12 bits). The memory data includes position data and operation parameters, and is linked to a memory address. The position data represents a position in the analysis target area, and indicates a position where an operation specified by the operation parameter (for example, start, end, save, return) is performed. The number of bits of the position data depends on the size of the analysis target area and the positioning accuracy, but in FIG. 4A, for example, it is represented by 12 bits D3 to D14.
[0030]
In addition, the operation parameters specify the data area that specifies the save or return operation, the data area that specifies the direction in which the electron beam is moved during the save or return, and the execution / non-execution of the scan (the beam stops on the spot). Data area to be provided.
[0031]
In the data area for specifying saving / returning, “saving” indicates a saving operation that removes the beam from the irradiation position, and “returning” specifies that the beam removed from the irradiation position by the saving operation is returned to the irradiation position. Represents the action.
[0032]
In the data area for designating the moving direction of the beam, designation of “upper” and “lower” represents in which direction the beam is swung in the save or return operation. In FIG. 2, when the negative direction of y is the upward direction and the positive direction of y is the downward direction, designation of “up” represents an operation of shaking the beam in the negative direction of y, and designation of “down” is This represents an operation of swinging the beam in the positive direction of y.
[0033]
Thus, for example, according to the designation of “up”, in the save {circle over (2)}, the save is performed by swinging the beam upward with respect to the non-scanning region C, and in the return {circle around (3)}, the non-scanning region C is set. Return the saved beam by shaking the beam upward. Further, according to the designation of “down”, in the save {circle over (2)}, the save is performed by swinging the beam downward with respect to the non-scanning region C, and in the return {circle over (3)}, the downward direction with respect to the non-scanning region C. Return the saved beam by shaking the beam.
[0034]
In the data area for specifying execution / non-execution of scanning, “ON” and “OFF” specify whether scanning is performed or not, and “ON” is set at the start point of FIG. Then, the scanning is started, and the scanning is ended by turning OFF at the end point of FIG. A two-dimensional scan is performed in the analysis target region between the start point and the end point, and during the two-dimensional scan, if the evacuation is designated in the region, the beam to be scanned is evacuated to irradiate the sample If the return is specified, the saved beam is returned to resume irradiation of the sample. FIG. 4D shows the time of scanning between the start of scanning and the end of scanning. When there is no saving / returning, the saving / returning and operation designation are performed in the upper / lower data area in the operation parameters. Absent.
[0035]
In the area designation data format representing the start point in FIG. 4C, address data corresponding to the start point is set as the memory address, and position data (Xs, Ys) at which scanning is started is set as the memory data. The In the area designating data format representing the end point in FIG. 4F, address data corresponding to the end point is set for the memory address, and end position data (Xe, Ye) is set for the memory data. The operation parameter “ON / OFF” is set to “OFF”.
[0036]
Also, in the area designation data format representing saving / returning in FIG. 4E, address data corresponding to the position where each operation is performed is set in the memory address, and the position data (XA, YA) of each operation is set in the memory data. , (XB, YB) are set.
[0037]
Further, in the area designation data format representing before the start of FIG. 4B and after the end of FIG. 4G, the operation parameter “ON / OFF” is set to “OFF” and scanning is not performed. By changing the setting of the start point and end point, arbitrary area scanning can be performed.
[0038]
The function of the image display means 13 is to generate position data and operation parameters based on the settings of scan start, scan end, save and return, and store them in the storage means of the control CPU / memory 10.
[0039]
Scanning by the electron beam analyzer 1 is performed as follows. The scan generator 2 is a binary counter that counts a pulse train having a predetermined frequency, and generates a counter output. The counter output is output to the control CPU / memory 10 and the D / A converter 3.
[0040]
The counter output input to the D / A converter 3 is converted into an analog signal, and a scanning signal of a sawtooth wave is formed. FIG. 5B is an example of a sawtooth wave formed by a D / A converter, and shows one scan in the x direction. The formed sawtooth wave is sent to the control amplifier / power amplifier 4 to form a drive current for driving the beam scanning coil 5. The beam scanning coil 5 deflects the electron beam emitted from the electron beam source by this driving current, and scans the beam on the analysis sample S.
[0041]
On the other hand, when the counter output input to the control CPU / memory 10 coincides with the memory address set in the area designation data format, the data set in the memory data is output. The control CPU / memory 10 outputs start and end data, and save and return control commands at a predetermined timing corresponding to the counter output.
[0042]
The start and end data are set in the preset buffer 11 to determine the start and end points of scanning. The preset buffer 11 sends the set start point and end point address data to the D / A converter 3. The D / A converter 3 monitors the counter output from the scan generator 2 and starts forming a sawtooth wave when it coincides with the address data at the start point, and generates a sawtooth wave when coincident with the address data at the end point. Finish formation.
[0043]
Thereby, the sawtooth wave is formed between the start point and the end point, and is not formed before the start point and after the end point. Since scanning is performed by beam deflection using a sawtooth wave, scanning is performed only between the start point and the end point at which the sawtooth wave is formed. Therefore, the range of the scanning region can be arbitrarily set by changing the start point and the end point.
[0044]
On the other hand, the save and return control commands output from the control CPU / memory 10 are sent to the beam save circuit 12. The beam save circuit 12 receives the save control command, controls the save operation for the control amplifier / power amplifier 4, and receives the return control command to perform the return operation for the control amplifier / power amplifier 4. Take control.
[0045]
FIG. 5 is an example of signals for explaining scanning, saving and returning. 5A shows an example of the counter output, FIG. 5B shows an example of the sawtooth wave, and FIG. 5C shows an example of the save signal formed by the save and return control commands. FIGS. 2D and 2E show an example of the drive current supplied to the beam scanning coil 5. Note that the example shown in FIG. 5 shows a case in which the start, retreat, return, and end of scanning are performed during one scanning in the x direction.
[0046]
In the counter output shown in FIG. 5A, Xs is a counter value at the start point, XA is a counter value for the saving operation, XB is a counter value for the return operation, and Xe is a counter value at the end point.
[0047]
When the counter value reaches Xs, the start point address is set in the preset buffer 11, and the D / A converter 3 starts to form a sawtooth wave with a magnitude corresponding to this address value (FIG. 5B). A) inside. When the counter value reaches Xe, the end point address is set in the preset buffer, and the D / A converter 3 finishes the formation of the sawtooth wave (b in FIG. 5B).
[0048]
While the sawtooth wave is being formed, for example, if a control command for saving is output between the counter value XA and XB-1, a save signal (FIG. 5C) is output from the beam save circuit 12. The The control amplifier / power amplifier 4 combines the sawtooth wave (FIG. 5 (b)) and the save signal ((FIG. 5 (c)) to generate the drive current (FIG. 5 (d) or FIG. 5 (e)). Output.
[0049]
The electron beam is scanned by this drive current. The save signal can remove the beam from the analysis region by increasing the deflection amount of the beam. Further, the save signal indicated by the solid line and the save signal indicated by the broken line in FIG. 5C have different beam deflection directions, and the beam does not pass through the non-irradiated region during the deflection of the beam. Set as follows. The drive current has a waveform shown in FIG. 5D or FIG. 5E, depending on the direction of the save signal in FIG.
[0050]
In FIG. 3, a detector 6 detects characteristic X-rays, secondary electrons, and reflected electrons emitted by scanning a beam on an analysis sample S, and outputs a detection signal. The detection signal is amplified by an amplifier, and image digital data is formed in synchronization with HD (vertical signal), VD (horizontal signal), and dot clock signals from the scan generator 2, and the image memory / video D / Record in A8. The image memory / video D / A 8 sends the video signal formed by converting the recorded image digital data into an analog signal to the video capture of the interface 9 and displays it on the image display means 13. The display of the image data can be performed in real time because it can be performed simultaneously with image acquisition by beam irradiation.
[0051]
FIG. 6 is a circuit diagram showing an example of a configuration for forming a drive current, and FIGS. 7 and 8 are an example of a scanning state diagram and an example of region designation data for explaining the operation of this beam evacuation circuit. 6 includes the scan generator 2, the D / A converter 3, the control amplifier / power amplifier 4, the preset buffer 11, and the beam save circuit 12 shown in FIG. 3, and includes a control CPU / memory 10 (FIG. 6). A control signal is received from (not shown), and the formed drive current is output to the beam scanning coil 5 (not shown in FIG. 6).
[0052]
6, the scan generator 2, the D / A converter 3, the control amplifier / power amplifier 4, and the preset buffer 11 in FIG. 3 are a reference clock 22 and a 12-bit counter (X counter 24, Y counter 25), 12 respectively. The bit D / A converter (26, 27), the amplifier (28, 29), and the preset buffer 23 are supported.
[0053]
Further, the beam save circuit 12 stores the area designation data, the decoder 30 that decodes the output of the storage means 21 and switches the polarity of the beam save, and the amplifier 29 for Y scanning based on the output of the decoder 30. A evacuation switch 31 for applying an evacuation signal is provided. The retract switch 31 deflects the beam by applying an excessive voltage to the sawtooth wave that becomes the scanning signal, and the retract switch 31 that avoids irradiation of the beam to the non-scanning region switches the polarity of the applied excess voltage between positive and negative voltages. Thus, the deflection direction of the beam can be switched. SW1 is a read / write signal switch, SW2 is a chip select switch, and SW3 is a scanning switch.
[0054]
The scanning area designation data is written into the storage means 21 by closing the addresses A0 to A23 and the data D0 to D14, SW1 and SW2, and opening SW3. After the writing is completed, SW1 and SW2 are opened, and SW3 is closed to set the ground voltage.
[0055]
Scanning in the x direction is performed by a sawtooth wave drive signal formed by the X counter 24, 12-bit D / A 26 and amplifier 28, and scanning in the y direction is performed by the Y counter 25, 12-bit D / A 27, and amplifier. This is performed by a sawtooth wave drive signal formed by the reference numeral 29. Further, the save and return operations are performed by applying an excessive voltage to the sawtooth wave of the y scan by the save switch 31.
[0056]
Next, scanning, retraction operation, and return operation in the electron beam analyzer of the present invention will be described with reference to FIGS.
[0057]
In the example shown in FIG. 7, the position of the end point represented by (Xe, Ye) from the position of the start point represented by (Xs, Ys) in the scanning target area (the entire rectangular area A in the figure). The scanning area is defined as a scanning area, and a scanning operation in which the sample is not irradiated with the beam is performed in the non-scanning area C indicated by the oblique lines in the scanning area. This non-scanning area C is set by the save and return operation parameters in the area designation data. Note that the start point and the end point can be set at an arbitrary position and an arbitrary number of sets in the scanning target region. In addition, an arbitrary position and an arbitrary number of sets can be set for the set of saving and returning.
[0058]
Scanning starts from a position (for example, Xs, Ys) determined by the control CPU / memory, and scanning for one line is completed by scanning to the final position in the x direction at the same position in the y direction (FIG. 7). A) inside. The area designation data indicated by a in FIG. 8 shows an example of data for one line.
[0059]
After the scanning of the one line is completed, the data of the address portion indicated by b in the next FIG. 8 is set to Ys + 1 in the y direction, thereby scanning the next one line (b in FIG. 7).
[0060]
When there is a non-scanning region C in which beam irradiation is not performed in the analysis target region A, operation parameters for saving and returning are set along the boundary of the non-scanning region C. C2 and d2 in FIG. 8 are examples of operating parameters for saving, and c3 and d3 in FIG. 8 are examples of operating parameters for returning. The save operation is an example in which the pixel position on the boundary of the non-scanning region C is set as the set position, and the return operation is performed on the pixel position on the boundary of the non-scanning region C in the scanning direction. ing.
[0061]
In the scanning line represented by c in FIG. 7 and FIG. 8, the scanning is continued to the position where the evacuation is set (c1), and the upward direction on the drawing shown in FIG. 7 at the position (XA, YA) where the evacuation is set. A retracting operation is performed by swaying the beam (c2). Here, the upward direction means a direction in which the beam is shaken so as not to irradiate the non-scanning region C, and any direction can be used as long as it does not irradiate the non-scanning region C. Thereafter, a retracting operation is performed in the same manner until a return operation parameter appears, thereby avoiding irradiation of the beam onto the non-scanning region C. Note that whether the beam swing direction in the retracting operation is set to the upper side or the lower side can be determined by the shape of the non-scanning region C.
[0062]
When reaching the position (XB, YA) where the return is set, the beam is moved downward on the drawing of FIG. 7 to return to the original scanning position (c3). Here, the downward direction means a direction in which the beam swung upward in the previous retreat operation is returned to the original, and the beam is swung so as to irradiate the scanning line. In this case, the return direction at this time is upward. In the scanning line indicated by d in FIG. 7 and FIG.
[0063]
When the end point position (Xe, Ye) for ending the scan is set in the analysis target region, the scan can be stopped based on the “OFF” operation parameter set at this position. Scanning can be stopped by, for example, inputting an “OFF” signal to the input enable of the 12-bit D / A converters 26 and 27 without stopping the output of the counter value. FIG. 8E shows an example of area designation data for setting the end position.
[0064]
According to the configuration of the electron beam analyzer of the present invention, when observing a sample having a structure that is damaged by electron beam beam irradiation, beam irradiation and non-irradiation are selectively set along the structure and beam irradiation is performed. As a result, an accurate analysis result can be obtained.
[0065]
In addition, according to the form of the electron beam analyzer of the present invention, in the observation and analysis of the vicinity of the sample where charge-up occurs due to electron beam irradiation, analysis can be performed under conditions of high acceleration voltage and large current. Analysis accuracy is improved.
[0066]
【The invention's effect】
As described above, according to the electron beam analyzer of the present invention, the scanning region of the electron beam can be arbitrarily designated. In addition, a two-dimensional image of an arbitrarily designated electron beam scanning region can be observed in real time.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a command area designated by an electron beam analyzer of the present invention.
FIG. 2 is a diagram for explaining each operation of scanning, retracting, and returning an electron beam with respect to a designated area.
FIG. 3 is a block diagram for explaining the outline of the electron beam analyzer of the present invention.
FIG. 4 is a diagram showing a data format for area designation according to the present invention.
FIG. 5 is an example of signals for explaining scanning, evacuation and return according to the present invention.
FIG. 6 is a circuit diagram showing a configuration example for forming a drive current according to the present invention.
FIG. 7 is a scanning state diagram for explaining the operation of the beam withdrawal circuit of the present invention.
FIG. 8 is a scanning state diagram and an example of region designation data for explaining the operation of the beam save circuit of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electron beam analyzer, 2 ... Scan generator, 3 ... D / A converter, 4 ... Control amplifier / power amplifier, 5 ... Beam scanning coil, 6 ... Detector, 7 ... Amplifier / A / D converter, 8 Image memory / video D / A converter, 9 User interface, 10 Control CPU / memory, 11 Preset buffer, 12 Beam save circuit, 21 Storage means, 22 Reference clock, 23 Preset buffer, 24 ... X counter, 25 ... Y counter, 26, 27 ... 12-bit D / A converter, 28, 29 ... Control amplifier / power amplifier, 30 ... Decoder, A ... Analysis target area, B ... Scanning area, C ... Non-scanning Area, S ... sample.

Claims (4)

In an electron beam analyzer that performs sample analysis by two-dimensional scanning of an electron beam,
Storage means for storing, for an analysis target area represented by a plurality of pixels, area designation data including position data for determining the position of each pixel in the area and operation parameters for determining an operation of an electron beam at the pixel position When,
An electron beam control means for controlling electron beam irradiation,
The electron beam control means sequentially reads position data and operation parameters from the storage means, and irradiates or non-irradiates an electron beam on the sample based on the operation parameters with respect to the position determined by the position data. An electron beam analyzer characterized by two-dimensional scanning. The operation parameter includes a standby parameter for determining a standby operation in which the electron beam is removed from the irradiation position to be in a non-irradiation state, and an electron beam that has been removed from the sample by the standby operation is returned to the sample to be in an irradiation state. Includes return parameters that define the action,
The electron beam analyzer according to claim 1, wherein the control unit starts a standby operation by a standby parameter and ends the standby operation by a return parameter. The standby parameter defines a standby direction of the electron beam with respect to the scanning line,
The electron beam analyzer according to claim 2, wherein the control unit controls the deflection direction of the electron beam based on a saving direction defined by a waiting parameter. Setting means for setting the scanning region of the electron beam with respect to the analysis target region;
Based on the set scanning area, the position specifying data generating means for generating position data for determining an operation position of a predetermined operation performed in the scanning area, and an operation parameter for determining the operation content,
The electron beam analyzer according to claim 1, wherein the storage unit stores the position data and operation parameters as region designation data.

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