JPH03257750A - Scanning electron microscope - Google Patents

Abstract

PURPOSE:To improve the operativeness of a device for transfer of a visual field by transferring the visual field for a distance inputted from an input equipment, by driving a stage on which a sample is placed, when the magnification is lower than an arbitrarily preset magnification. CONSTITUTION:Deflection signals generated in a deflection signal generator 13 are able to vary a scanning range on a sample with a computer 20, and excite deflection coils 3a, 3b with a deflection amplifier 8 to scan an electron beam 2 on a sample 6 two-dimensionally. A magnification is determined by the scanning range. When a distance to be transferred inputted from an input equipment 21 is lower than that of a preset magnification, the computer 20 selects a stage driving circuit 12 to transfer a stage 7, on which the sample 6 is placed. Thereby the operativeness of the device can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scanning electron microscope suitable for moving the field of view to a predetermined position in a scanning electron microscope and similar devices thereof.

[Conventional technology]

Conventional devices include Utility Model Application No. 61-135458 and Utility Model Application No. 6
As described in No. 1-72613, electrical field movement and field movement by stage drive were used independently.

In other words, conventionally, when an operator has observed an image at low magnification based on experience, he or she selects a field-of-view moving means using a stage drive that has a wide field-of-view movement range, and selects a field-of-view moving means using a stage drive that has a wide field-of-field movement range, and selects an image 1 at high magnification! In those cases where the visual field movement range is narrow, electrical visual field movement is selected and used because it allows accurate control of the visual field movement distance. This is because input devices for electric field-of-view movement and field-of-view movement means using stage drive were separately provided.

[Problem to be solved by the invention]

In the above conventional technology, the field of view moving means by stage drive also
Even though the electric field of view moving means is a means of moving the same observation field of view, no consideration was given to effectively combining both means, and there was a problem in terms of operability.

An object of the present invention is to effectively combine two visual field moving means by taking advantage of the features of each visual field moving means, thereby improving the operability of visual field moving.

[Means to solve the problem]

The above object is achieved by driving the stage on which the sample is placed to move the field of view by the amount of field of view movement inputted by the input device when the magnification is below an arbitrary preset magnification.

Regarding claim 2, at a magnification higher than the magnification described in claim 1, while the field of view can be electrically moved by deflecting the electron beam to change the amount of field of view inputted by the input device, The field of view is electrically moved by deflecting the electron beam, and when the field of view exceeds the range that can be moved by the above means, the field of view is moved by driving the stage on which the sample is placed.

[Effect]

When the magnification is below a predetermined magnification, by automatically selecting means for driving the stage on which the sample is placed to move the field of view, it is possible to select a stage drive that can move over a wide range, thereby improving operability.

In addition, at a magnification higher than a predetermined magnification, a means for electrically moving the field of view by deflecting the electron beam is used, while a means for electrically moving the field of view by deflecting the electron beam is used; If the field of view is exceeded, the stage on which the sample is placed is driven and the means for moving the field of view is automatically selected. If the field of view exceeds the range that can be electrically moved,
Operability can be improved because a stage drive that can be moved over a wide range can be selected without manually switching the field of view moving means.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. An electron beam 2 emitted by an electron gun 1 is narrowed by an objective lens 5 and irradiated onto a sample 6 . The objective lens 5 is excited by an objective lens power supply 10.

In addition, the deflection signal generated by the deflection signal generator 13 can change the scanning range on the sample by the computer 20, and the deflection amplifier 8 excites the deflection coils 3a and 3b to cause the electron beam 2 to two-dimensionally scan the sample 6. do. The magnification is determined by this scanning range.

Further, at this time, signals generated by the electron beam 2 incident on the sample 6 (secondary electrons 9 reflected electrons, etc.) are converted into electrical signals by the detector 8, and converted from analog signals to digital signals by the A/D converter 14. Converted image memory 15
is memorized. This image memory 15 is connected to a D/A converter 16
The digital signal is converted into an analog signal and applied to the grid as a luminance signal of the image display CRT.

At this time, the A/D converter 142 image memory 15°D/A
The converter 16 receives a timing signal from the deflection signal generator 13 for performing A/D conversion and displaying an image. Also,
The deflection coil 19 of the image display CRT 18 is excited by the deflection amplifier 17 based on the deflection signal from the deflection signal generator 13.

On the other hand, the stage on which the sample 6 is placed is moved by the stage drive circuit 12 based on an input signal from an input device 21 such as a joystick or trackball, thereby changing the scanning position of the electron beam 2 on the sample 6 and changing the field of view. Moving.

This visual field movement amount is calculated by the computer 20 based on the input signal from the input device 21 and realized by the stage drive circuit 12.

Furthermore, the image shift coils 4a and 4b of the electron beam 2 are excited by the image shift circuit 9 based on an input signal from the input device 21, thereby changing the scanning position of the electron beam 2 on the sample 6 and moving the field of view. The amount of movement of this field of view is calculated by the computer 20 based on input signals from the input device 21 and realized by the image shift circuit 9.

In the above configuration, as an embodiment of claim 1, the movement amount inputted by the input device 21 is
As shown in the figure, if the magnification is less than the preset magnification, the computer 20 selects the stage drive circuit 12 and
This can be done by moving the stage 7 on which it is placed.

Furthermore, as an embodiment of claim 1, the input device 21
As shown in FIG. 2, when the input movement amount returns to a state higher than the preset magnification, the field of view can be moved by switching to the original field of view movement means at the current magnification. For example, if the original field of view moving means at the current magnification is a means of deflecting the electron beam 2 and moving the field of view, the computer 20 selects the image shift circuit 9 as the field of view moving means, and the image shift coils 4a and 4b are activated. This can be implemented by modulating and deflecting the electron beam 2.

As described above, according to the present embodiment, when the magnification is lower than a preset magnification, the field of view moving means by the stage that can move the field of view over a wide range is used, while when the magnification is higher than the preset magnification, the field of view moving means at the current magnification is used. can be used automatically, improving operability.

As an embodiment of claim 2, if the amount of movement inputted by the input device 21 is less than a preset magnification as shown in FIG. This can be done by moving the stage 7 on which it is placed. On the other hand, at a magnification higher than the preset magnification, the image shift circuit 9 is selected by the computer 20 and the image shift 4a is
4b to deflect the electron beam 2. If the field of view exceeds the range that can be electrically moved by deflecting the electron beam, the computer 20 selects the stage drive circuit 12 to move the stage 7 on which the sample is placed. This can be achieved by moving the .

As described above, according to this embodiment, when the magnification is lower than a preset magnification, the field of view moving means by the stage, which can move the field of view over a wide range, is used.On the other hand, when the magnification is higher than the preset magnification, the electron beam is deflected to Electric field of view moving means can quickly and accurately move the field of view in a narrow area within the range where the field of view can be moved electrically.
Operability can be improved because the field of view moving means using the stage can be used automatically.

〔Effect of the invention〕

According to the present invention, it is possible to automatically select an effective field-of-view moving means or a stage-driven field-of-view moving means depending on the magnification value, thereby improving operability.

In addition, in a range exceeding the preset magnification, if the amount of movement input from the input device can be achieved by the electric field of view moving means, then the electric field of view moving means can be used; Since the means for moving the field of view by stage drive can be automatically selected, it has the effect of further improving operability.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a scanning electron microscope showing one embodiment of the present invention, and FIGS. 2 and 3 are flow diagrams of the embodiment of the present invention. 2. Electron beam, 4. Image shift coil, 6. Sample, 7. Stage, 18. CRT, 20. Combination lead 1.

Claims (1)

[Claims] 1. A means for electrically moving a field of view by deflecting an electron beam, a means for moving a field of view by driving a stage on which a sample is placed, and inputting the amount of movement of the two field of view moving means. In a scanning electron microscope that shares an input device, when the magnification is below an arbitrary preset magnification, the field of view movement amount input from the input device is configured to move the field of view by driving the stage on which the sample is mounted. A scanning electron microscope featuring: 2. In the scanning electron microscope described in claim 1,
At a magnification higher than the arbitrary preset magnification, the electron beam is moved while the field of view movement amount inputted from the input device can be moved by the means for electrically moving the field of view by deflecting the electron beam. The field of view is electrically moved by deflecting the sample, and when the field of view moves beyond the range that can be moved by the above means, the field of view is moved by automatically switching to a means for driving the stage on which the sample is placed. A scanning electron microscope characterized by: