JPS6276247A - Scanning type electron microscope - Google Patents

Abstract

PURPOSE:To improve the operationability, when setting an observing position or magnification, by displaying a window frame on a CRT while interlocking the setting of the central position or an observing area with the central position and the fluctuation of a scanning beam at the sample side within a scanning range. CONSTITUTION:At first, a low magnification is set in a magnification controller 2 to open the switches S1, S2 while to close the switch S3 then a variable resistor 7 for setting a frame size and a variable resistor 8 for setting the central position are operated to display a window frame for indicating a desired position and range onto a CRT 9. Thereafter, S3 is opened while S1 and S2 are closed to read out the setting signals of the variable resistors 7, 8 by means of the magnification controller 2 and a bias generator 5 thus to provide a scanning signal applied with D.C. bias to a deflection coil 12 through an adder 3, and to display a fully enlarged image of sample in the window frame onto the CRT 9. Since the window frame and the beam scanning are interlocked, the operationability can be improved considerably.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method for setting the position and magnification of an electron image in a scanning electron microscope.

Conventional technology When observing a sample using a scanning electron microscope, a wide range of the sample surface is observed at low magnification, an observation point is selected, and the selected point is enlarged and viewed.

At this time, since the screen of the observation CRT is fixed, unless the sample is moved so that the desired place is at the center of the observation CRT and the magnification is increased, the desired place will be off the observation CRT screen. Also, even if you position the place you want to view at the center of the observation CRT, the next time you increase the magnification, the observation CRT
There were many cases where the edge of the area I wanted to see on the T's screen went off the screen, or only a part of the area I wanted to see was visible, and I had to set the magnification again.

C0 Problems to be Solved by the Invention When observing a sample with a scanning electron microscope, the sample must be set so that the desired location is in the center of the observation CRT screen, and then magnified. Since the magnification is specified regardless of the size of the area to be observed, it is troublesome to set the magnification so that the area to be viewed fills the screen when the magnification is increased. The present invention aims to improve this operability.

21. Means for Solving Problems The present invention projects a wind frame for specifying the observation area of the sample on the observation CRT display screen, and scans the center position of the window frame in conjunction with the setting of the observation area. An electrical control unit was set up to freely set the center position and amplitude of the scanning range of the scanning beam on the sample side of the electron microscope.

E1 Effect The present invention projects a wind frame on the observation CRT display screen, and in conjunction with the center position of this wind frame and the setting of the observation area, the center position of the scanning beam on the sample side of the scanning electron microscope, Since an electric control unit for freely setting the amplitude of vibration is installed, the observation position double magnification in the scanning electron microscope can be set visually, improving the operability of the scanning electron microscope.

To, Example FIG. 1 is a block diagram of the present invention.

1 is an operation signal generator that sends signals to control the scanning of the observation CRT 9 and the operation beam on the sample side in the X-axis and Y-axis directions;
6 is a window frame signal generator, which generates a signal to display a frame-shaped image on the observation CRT that specifies the range of the enlarged image when the magnification is switched to high magnification;
When the CRT 9 is closed, the video signal sent from the detection section 11 is combined with the video amplifier 10 and displayed as a white frame on the sample image of the observation CRT 9.

7 is a variable resistor for setting the frame size, and CR for observation.
The size of the wind frame on the T is set to 1/1 to 1/20 of the CRT screen size.

2 is a variable gain amplifier that amplifies the scanning signal with a magnification controller, and when switch S1 is closed, the size of the wind frame is read as an electrical signal from the resistance value of the variable resistor mentioned above, and the electrical signal is In correlation, the amplitude of the input signal to the deflection coil 12 is converted so that the range of the sample surrounded by the wind frame matches the scanning range of the scanning beam on the sample side. 8 is a variable resistor for setting the center position, which sets the center position of the wind frame. 5 is a bias generator, and when the switch S2 is closed, the variable resistor 8
The resistance value of the sensor is read as an electrical signal, and a DC bias voltage is generated according to the electrical signal. The DC bias is added to the scanning signal by the adding circuit 3 and applied to the deflection coil 12.

Since a DC bias is applied to the 2d scanning signal applied to the deflection coil 12, the center position of the scanning beam on the sample side is shifted from the optical axis of the electron optical system and is aligned with the center position of the wind frame. In this way, the scanning range of the scanning beam is adjusted by the magnification controller 2, the center position of the scanning range of the scanning beam is adjusted by the addition circuit 3, and the scanning beam on the sample side is deflected by the deflection coil 12, Scan the specified range of . Secondary radiation emitted from the sample is detected by the detector 11 and sent to the video amplifier 10 as a video signal. The same signal is the video amplifier 10
The signal is amplified to become a modulation signal of the intensity of the scanning beam of the observation CRT 9, and a grayscale image is displayed on the observation CRT. The image is scanned in synchronization with the scanning of the sample and observation CRT by a scanning signal sent from a scanning signal generator.

With the above configuration, initially the magnification controller is set to a low magnification, for example 1.
00 times, open the switches SL and S2, and close the switches S3 to display the sample image on the observation CRT, and operate the variable resistor 7 for setting the frame size and the variable resistor 8 for setting the center position. , projects a wind frame displaying the desired position and range on the observation CRT screen, then opens switch S3 and closes Sl and S2, the wind frame disappears from the observation CRT and the window frame that was previously in the window frame disappears. The displayed sample image is enlarged to fill the observation CRT and displayed.

In this way, the image within the specified window frame is enlarged and displayed to fill the raster of the central input circuit of the observation CRT without moving the sample. In addition, the magnification at that time is NX 100 when the initial magnification is 100 times and the size of the wind frame is 1/N. Since the wind frame can be set between 1/1 and 1/20, the screen magnification is 100 to 2000 times more. Also, SL,
Open S2 and specify again with the wind frame, and again ring 81. If S2 is closed, enlarged display can be performed again in the same manner as above. In this way, multi-step enlargement is possible, and the screen can be enlarged one after another, starting from no enlargement, to gradually specifying observation points on the sample in detail.

In FIG. 2, FIG. 44 is an initial low magnification screen. When the wind frame F is specified as shown in Figure A, the range of F is expanded to the full raster like an aperture by the magnification controller 2 and the adder circuit 3. Also, if the wind frame F is designated in the same way at the opening, it will be enlarged as shown in Figure C.

In this way, by deflecting the scanning beam of the scanning electron microscope body according to the settings without moving the sample, it is possible to see the desired area and the desired size.

G. Effects The present invention uses the method described above to eliminate the troublesome setting of observation position and magnification in conventional scanning electron microscopes, and improves the operability of scanning electron microscopes.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention, and FIG. 2 is an operation explanatory diagram. Agent: Hiroshi Agata, Patent Attorney Figure 1 Figure 2

Claims (1)

[Claims] A wind frame is projected on the specimen image of the observation CRT, and the center position of the wind frame and observation area settings are
A scanning electron microscope equipped with an electronic control mechanism that is linked to the center position and amplitude of the scanning beam scanning range on the sample side.