JPH04184849A - Electron microscope - Google Patents

Abstract

PURPOSE:To photograph joint photos simply and accurately by specifying on a visual field the coordinates of two confronting apexes of a rectangle surrounding the photographing scope, allowing a specimen stage to travel automatically, and performing photographing in synchronization with the traveling. CONSTITUTION:The magnification of enlargement is set low, and the whole photographing scope is displayed on a fluorescent board 6. A specimen stage 9 is moved by operating a rotary encoder 16a so that the left top apex and right bottom apex of the rectangle surrounding the photographing scope lie each in the center of the view field, and the coordinates of the stage 9 at the time are registered in a memory 17. Then an input device 16 is operated to specify the enlargement ratio at the time of photographing and the overlapping amount of view fields adjacent to each other. The X-direction and Y-direction distances of the photographing scope are calculated using a calculating device 18, which also computes the number of copies photographed in the X- and Y-direction on the basis of these values obtained. An MPU 14 moves the stage 9 in matrix direction step by step according to the abovementioned values, and the enlarged image is photographed one by one in synchronization with traveling of the stage 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electron microscope capable of photographing observation images, diffraction images, etc., and particularly relates to an electron microscope suitable for creating stitched photographs. be.

(Prior art) Until now, when creating stitched photographs using an electron microscope, the longest diameter part in the lateral direction of the sample to be photographed was first selected, and then the field of view was adjusted to the longest diameter part by operating the specimen fine movement device. The camera sequentially moves in the horizontal direction from the left end (right end) to the right end (left end) in consideration of the overlapping amount, and determines the approximate number of shots in the horizontal direction.

Next, select the longest diameter part of the sample in the vertical direction, and then operate the sample fine movement device to move the field of view from the top (bottom end) to the bottom end (top end) of the longest diameter part in the vertical direction, taking into account the amount of overlap. Move to determine the approximate number of shots in the vertical direction.

Furthermore, once the approximate number of shots in the vertical and horizontal directions is determined as described above, a test feed is performed to confirm the number of shots.

(Problem 8 to be solved by the invention) In the above-mentioned conventional technology, the approximate number of images to be taken in the vertical and horizontal directions had to be determined while sequentially moving the field of view in the vertical and horizontal directions, making the operation complicated. We were informed that it would take a long time to prepare.

Moreover, while determining the approximate number of shots as described above,
Since the sample is also irradiated with the electron beam during subsequent test feeding, there is a problem in that if the sample is sensitive to electron beams, the sample will be damaged before the imaging is completed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electron microscope that solves the above-mentioned problems of the prior art, allows easy and accurate stitching of photographs, and reduces the adverse effects of electron beams on a sample.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention sequentially moves the sample stage and stitches together a plurality of photographs taken by partially overlapping adjacent magnified fields of view. An electron microscope for creating a single photograph is characterized by the following measures taken.

(1) A means for specifying the coordinates of two mutually opposing vertices of a rectangle enclosing the photographing range, and determining the number of photographs in the matrix direction of the rectangle based on the coordinates of the two vertices, the magnification, and the amount of overlapping. means for sequentially moving the sample stage in the matrix direction according to the apex coordinates, magnification, overlapping amount, and number of images to be photographed; and means for photographing enlarged images in synchronization with the movement of the sample stage. did.

(2) a means for specifying the coordinates of each vertex of a polygon surrounding the photographing range, and a matrix that specifies the coordinates of each vertex of the polygon surrounding the photographing range, and a matrix so that at least the entire area of the i-gon is photographed based on the coordinates of each vertex, the magnification, and the amount of overlapping. a means for determining the number of shots in relation to the direction;
The sample stage was provided with means for sequentially moving the sample stage in the matrix direction according to the vertex coordinates, magnification, overlapping amount, and number of photographed images, and means for photographing enlarged images in synchronization with the movement of the sample stage.

(3) The apparatus further includes means for calculating a photographing start area and driving the sample stage to a position where the enlarged field of view becomes the photographing start area, so that the sample stage is sequentially moved from the photographing start position.

(Function) According to configuration (1) above, the shooting range is determined simply by inputting two vertex coordinates, and the shooting range, magnification and overlapping amount are used to capture the entire shooting range. The number of shots taken can be determined by calculation.

Furthermore, since the movement pattern of the sample stage is calculated based on the photographing range, magnification, overlapping amount, and number of photographed images, it becomes possible to easily take continuous photographs.

According to configuration (2) above, the shooting range is determined simply by inputting the coordinates of each vertex of the polygon, and the shooting range, the magnification, and the overlapping amount are used to determine the shooting range necessary to shoot the entire shooting range. The number of shots is calculated.

In addition, since the movement pattern of the sample stage is determined by calculation based on the photographing range, magnification, overlapping amount, and number of photographed images, it becomes possible to take continuous photographs easily and without waste.

According to the above configuration (3), the sample stage is automatically set to the photographing start position, so that continuous photographs can be automatically photographed.

(Embodiment) FIG. 1 is a block diagram of an electron microscope which is an embodiment of the present invention, and FIG. 72 is a flowchart for explaining its operation.

An electron beam 2 emitted from an electron gun 1 is focused by an irradiation lens system 3 and irradiated onto a sample 4 on a sample stage 9.

The electron beam transmitted through the sample 4 is magnified by an imaging lens system 5 and forms an enlarged image on a fluorescent screen 6.

Further, when photographing an enlarged image, when the fluorescent screen 6 is opened, a film 8 in a camera 7 disposed below the fluorescent screen is exposed to an electron beam, and an enlarged image is recorded.

The sample stage 9 transfers the rotary motion of the motor 12 decelerated by the rotary reducer 11 to the linear actuator 10.
It is moved in the X direction by converting it into linear motion at . A rotary encoder 13 that shares the rotation axis of the motor 12 is connected to the motor 12, and pulse signals output from the rotary encoder 13 in accordance with the rotation of the motor 12 are counted by a microprocessor 14.

The rotation of motor 12 is regulated by power supplied from power supply 15 controlled by microprocessor 14 . The position of the sample stage 9 is detected by a sample position detector 27, and a detection signal is input to the microprocessor 14.

In addition, in order to make the explanation easier to understand, only the configuration for moving the sample stage 9 in the It also has one more set of actuators and the like.

The input device 16 includes a data input section for specifying the enlargement magnification and overlapping amount, and a data input section for specifying the magnification and overlapping amount, and the sample stage 9 according to the operator's operation.
When an operator operates the rotary encoder 16a, a pulse signal corresponding to the operation is sent to the microprocessor 1.
4 is input. Camera-controlled source 19 advances film 8 in response to instructions from microprocessor 14.

In such a configuration, when photographing a linked photograph of the observed images shown in FIG. 3, in step S10, the enlargement magnification is set low to display the entire photographing region 20 on the fluorescent screen 6. In step Sll, in order to specify the imaging range, the operator first operates the rotary encoder 16a to move the sample stage 9 so that the upper left vertex A of the rectangle 21 surrounding the imaging area 2o becomes the center of the field of view. The coordinates (XI, YL) of the sample stage 9 at that time are registered in the memory 17.

Next, the lower right vertex B of the rectangle 21 opposite to the vertex A
The operator operates the rotary encoder 16a to move the sample stage 9 so that the position becomes the center of the field of view, and registers the coordinates (X2, Y2) of the sample stage 9 at that time in the memory 17.

After completing the designation of the imaging range in this way, the operator operates the input device 16 in step S12 to designate the magnification M during imaging, and in step S13, the operator designates the overlapping amount δ between adjacent fields of view. .

In step S14, each coordinate of the sample stage registered in the memory 17 (Xl, Yl), (X2, Y
2), the microprocessor 14 uses the arithmetic unit 18 to calculate the distance LX (-X
2-Xi ) and the distance in the Y direction LY (-Y2-Y
l ) is calculated.

In step 515, the enlargement magnification M1 overlap amount δ,
Based on the distances MLX and LY, the microprocessor 14 uses the arithmetic unit 18 to calculate the number n of images to be taken in the X direction and the number m of images to be taken in the Y direction. That is, in this embodiment, the photographing area 20 is divided into m rows and n columns and photographed.

When the number of shots is determined in this way, the station and knob S1
6, the imaging lens system 5 is controlled so that the magnification becomes the magnification M, and furthermore, the field of view is adjusted to the photographing start position, that is, the third
of said rectangle 21 shown in the figure.

The microprocessor 14 is placed in the upper left area Sll.
controls the power source 15 based on each of the data described above to drive the sample stage 9. It is desirable that the position of the region Sll be set so that the vertex A is located inside by an overlapping amount δ from the upper end and left end of the region Sll.

In step S17, the area Sll is photographed in synchronization with the movement of the sample stage 9, and then the camera control power source 1
9, the photographed film in the camera 7 is advanced and the next film is set.

In step 818, it is determined whether n images have been photographed in the X direction, and if not, step S19
A region 51 whose enlarged field of view is adjacent to the region Sll
The sample stage 9 is moved so that the position becomes 2.

Photographing is performed sequentially in the X direction in this manner, and then, when the photographing of the rectangular upper right area Sin is completed in step S17, n in the X direction is completed in step S18.
It is determined that the shooting of all images has been completed, and the processing is continued in step S.
Proceed to 20.

In step S20, it is determined whether or not imaging has ended in the Y direction. If not, in step S21, the sample stage 9 is moved so that the magnified field of view is in the first row.
is driven, and further, in step S22, the sample stage 9 is moved by one line in the Y direction, and the enlarged field of view is moved to the area 521.

Thereafter, in steps 817 to S19, the second row is sequentially photographed in the X direction in the same manner as described above.

Thereafter, when the photographing of the lower right area 5Iln of the rectangle 21 is completed, it is determined in step S20 that the photographing in the Y direction has been completed, and the process ends.

In the above-described embodiment, when registering the coordinates of two locations for specifying the shooting range, the magnification is lowered to display the entire shooting area, but the present invention is not limited to this. The present invention is not limited to this, and the coordinates of two locations may be registered while keeping the high magnification.

According to this embodiment, by simply specifying the coordinates of two mutually opposing vertices of a rectangle surrounding the imaging range in the field of view, the sample stage 9 is automatically moved sequentially from the imaging start position, and the sample stage 9 is also moved. Since photos are taken in synchronization with , it becomes possible to easily and accurately take stitched photos.

Moreover, since there is no need for test feeding, the time for irradiating the sample with the electron beam can be shortened, and damage to the sample caused by the electron beam can be suppressed.

By the way, in the above embodiment, since the photographing area 20 is not included in the lower left area Sml and the upper right area Sln of the rectangle 21, the film is wasted in these areas. Therefore, an embodiment for preventing such wasteful photographing will be described below.

FIG. 4 is a diagram for explaining a second embodiment of the present invention, and the same reference numerals as above represent the same or equivalent parts.

In this embodiment, a polygon 22 that surrounds the imaging area 20 without waste is used.
The vertices ASC, D%B, E, and F are registered in the same manner as in the first embodiment, and the number of images is set so that each part of the hexagon ACDBEF is photographed without omission. There are characteristics.

In this embodiment, the imaging area 20 is described as being surrounded by a hexagon, but it may be surrounded by any polygon depending on the shape of the imaging area.

According to this embodiment, since the photographing of a portion that does not include the photographing area is prevented, the film is not wasted.

(Effects of the Invention) As is clear from the above description, according to the present invention, the following effects are achieved.

(1) Simply by registering the coordinates of two mutually opposing vertices of a rectangle surrounding the photographing area, each stitched photo can be taken automatically, making it possible to take stitched photos easily and accurately.

Moreover, since there is no need for test feeding, the time for irradiating the sample with the electron beam can be shortened, and damage to the sample caused by the electron beam can be suppressed.

(2) By registering the coordinates of each vertex of a polygon surrounding the photographing area, it is possible to prevent parts that do not include the photographing area from being photographed, so that film is not wasted.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the first embodiment of the present invention, FIG. 2 is a flowchart for explaining the operation of FIG. 1, FIG. 3 is a diagram for explaining the operation of the first embodiment, and FIG. Figure 4 is the second
FIG. 3 is a diagram for explaining the operation of the embodiment.

Claims (3)

[Claims] (1) In an electron microscope that sequentially moves the sample stage and stitches together multiple photographs taken by partially overlapping adjacent magnified fields of view, a rectangular shape surrounding the photographed area is used. , a photographing area specifying means for specifying coordinates of two vertices facing each other; a magnification specifying means for specifying an enlargement magnification; an overlapping amount specifying means for specifying an overlapping amount; a number calculation means for calculating the number of images to be taken in the matrix direction of the rectangle based on the overlapping amount; and a sample stage that is sequentially moved in the matrix direction according to the vertex coordinates, magnification, overlapping amount, and number of images to be taken. An electron microscope comprising: a sample stage control means; and a photographing means for photographing an enlarged image in synchronization with the movement of the sample stage. (2) In an electron microscope that sequentially moves the sample stage and stitches together multiple photographs taken by partially overlapping adjacent magnified fields of view to create a single photograph, a polygon that surrounds the photographed area is used. a photographing area specifying means for specifying the coordinates of each vertex, a magnification specifying means for specifying an enlargement magnification, an overlapping amount specifying means for specifying an overlapping amount, and a number-of-photography calculation means for calculating the number of images to be taken in the matrix direction so that at least the entire area of the polygon is photographed; 1. An electron microscope comprising: a sample stage control means that sequentially moves in a matrix direction; and a photographing means that takes an enlarged image in synchronization with the movement of the sample stage. (3) further comprising means for calculating a photographing start area based on the respective vertex coordinates, magnification magnification, and overlapping amount, and driving the sample stage to a position where the magnified field of view is the photographing start area, sample stage control; 3. The electron microscope according to claim 1, wherein the means sequentially moves the sample stage from the imaging start position.