JPS60195860A - Dynamic observation display system - Google Patents

Abstract

PURPOSE:To observe and display an image having a specific phase with a simple device when a stress is applied by applying the desired stress to a sample under observation with stress generating elements, scanning the sample under observation with a probe, and extracting and displaying a signal generated from the sample under observation having a specific phase. CONSTITUTION:A sample 1 under observation is held by being sandwiched by stress generating elements 2 from both sides of a stress applying unit 4, and an optional static stress can be applied as required from outside the vacuum by rotating a static stress applying screw 3. An electron beam probe radiated from an electron gun 5 is image-formed as fine spot on the said sample 1 under observation by an electron lens 6. The electron beam probe scans over the sample 1 under observation by feeding X, Y scanning signals respectively to a scanning coil 7 from a scanning power supply control unit 12. Secondary electrons emitted from the sample 1 under observation while scanning are collected by a scintillation detector 8 and amplified, and the resultant image signal is amplified by a video amplifier 9 and signal-processed, and is fed to a signal processing unit 10.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a dynamic observation and display method, in particular, in which mechanical stress is repeatedly applied to the observed sample itself at high speed, and the observed sample is exposed to an electron beam probe or the like. Dynamic observation and display method that extracts an image of a specific phase from the image signal obtained by scanning and observes and displays it. (Technical background and problems) Observing magnetic domains or regions of dielectric materials is important in understanding the characteristics of various materials.

However, in the past, stress was statically applied sequentially to the front magnetostrictive element, etc., and a scanned image was obtained at rest with the predetermined stress applied. For this reason, the scanned image at the time of application of a specific stress under dynamically changing usage conditions does not necessarily match, and sufficient analysis could not be performed.

Furthermore, dynamic changes caused by vibrations in magnetic materials such as electromagnetic steel sheets, which are often used at commercial frequencies, are too slow to be observed using TV scans, etc., and there is a problem in that it is difficult to observe specific phases.

(Object and Structure of the Invention) An object of the present invention is to solve the above-mentioned problems, by applying stress to a sample to be observed using a stress generating element, and scanning the sample to be observed with a probe. The purpose is to obtain an image of a specific phase when stress is applied by extracting only a signal of a specific phase from among signals generated from a sample and displaying it on a display or the like. Therefore, the dynamic observation display method of the present invention changes the stress applied to the observed sample periodically and at high speed, and generates an image of a specific phase from the image signal obtained by irradiating the observed sample with a probe. A dynamic observation and display device that performs display includes a stress application section that periodically and rapidly changes the stress applied to the sample to be observed 4, and a stress application section that changes the stress periodically and at high speed. a probe scanning unit that synchronously scans the observed sample with a probe; a signal detection unit that detects a signal generated from the observed sample by scanning with the probe scanning unit; and a signal detected by the signal detection unit. The apparatus is characterized in that it includes a specific image extracting section that extracts an image of a predetermined phase from the specific image extracting section, and displays the image signal extracted by the specific image extracting section on a display.

(Example of the invention) The present invention will be described in detail below based on the drawings.

FIG. 1 is a configuration diagram of one embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams illustrating the configuration of one embodiment of the present invention shown in FIG. 1,
FIG. 4 shows a block diagram of another embodiment of the present invention.

In the figure, 1 is a sample to be observed, 2 is a stress generating element, 3 is a static stress applying screw, 4 is a stress applying device, 5 is an electron gun, 5-1 is an electron source, 5-2 is a Wehnelt cylinder, 5-3 is the anode, 6
1 is an electron lens, 7 is a scanning coil (X, Y), 8 is a scintillation detector, 9 is a video amplifier, 10 is a signal processing section, 11 is a display, 12 is a scanning electron microscope control section, 1
3 is a master 0SC114, 17 is a frequency dividing circuit, 15 is a drive signal-I generator 2L generator, 16 is a horizontal scanning signal generator, 18
is a vertical scanning signal generator, 19 is a counter, and 20 is P −
ROM, 21 is a phase switch, and 22 is a blacking control section.

In Fig. 1, reference numeral 1 indicates a sample to be observed, which is fixed to a stress applying device 4 placed on a sample moving table (not shown) such as a scanning electron microscope (movable in the X and Y directions). It is. The sample 1 to be observed is held in a sandwiched manner through the stress generating elements 2 from both sides of the stress applying device 4, and any static stress can be removed from outside the vacuum by rotating the static stress applying screw 3 shown in the figure. It can be applied as needed.

In addition, the electron beam probe that irradiates the observed sample 1 is an electron beam 1ff15-1 (filament) constituting the electron gun 5.
, is generated in a known manner by Wehnelt tube 5-2 and anode 5-3. The electron beam probe emitted from the electron gun 5 is imaged by an electron lens 6 on the sample 1 to be observed in the form of a minute spot (several thousand to several angstroms).

The electron beam probe is deflected by supplying the x-y scanning signal (sawtooth wave current) from the scanning electron microscope control section 12 to the illustrated scanning coils (X, Y) 7, respectively. This causes the electron beam probe to scan over the sample 1 to be observed. For example, secondary electrons emitted from the observed sample 1 during the scanning are collected and amplified by the illustrated snarration detector 8. The image signal amplified by the scintillation detector 8 is amplified by the video amplifier 9, and is also subjected to signal processing to a predetermined DC level, impedance conversion, etc. The video signal (2) output from the video amplifier 9 is supplied to the signal processing section 10.

The signal processing section 10 extracts a predetermined image signal from the video (No. Based on the synchronization signal ■ supplied from the microcontroller 12, a predetermined CRT scanning signal ■ as described later is supplied to the drive terminals (horizontal and vertical drive terminals) of the display 11. By doing this, the display 11 , a secondary electron image emitted from the sample I to be observed is displayed.

When the scanning electron microscope control unit I2 supplies, for example, an alternating stress application signal (2) to the stress generating element 2, an alternating stress is applied to the observed sample l, and a magnetostrictive effect or an electric current is generated in accordance with the stress. Displacement of the magnetic domain or change of the domain of the dielectric material occurs due to strain effects or the like.

However, in conventional scanning electron microscopy, the observed sample l is displaced along with the stress application signal, so even if a TV scanning device with a high scanning speed is used, the state of the displacement can be observed and
It cannot be displayed.

Therefore, the present invention supplies the stress application signal (2) that changes periodically and at high speed to the stress generating element 2, and extracts an image signal of a predetermined phase from the signal obtained by scanning the sample to be observed N1 to identify the Images during stress application will be observed and displayed. Figure 2 is shown below.

FIG. 2 is an explanatory diagram for explaining the process of sequentially sampling images of a specific phase from the video signal (2) in synchronization with the stress application signal (2) and displaying them on a display (CRT).

FIG. 2(A) shows an example of the waveform of the stress application signal (2), and shows a state in which the stress applied to the sample to be observed (1) changes almost sinusoidally. A luminance signal (2) corresponding to a specific phase shown in the drawing of the stress application signal (2) is sequentially extracted from the video signal (2) and displayed in the form of sequential brightness modulation at the topmost position in the drawing on the display 11. Similarly, the images are displayed at the next stage in the form of sequential brightness modulation.

FIG. 2(B) shows the sampling pulse signal waveform,
FIG. 2(A) shows a method for extracting a luminance signal (2) corresponding to a specific phase of the illustrated stress application signal (2) from a video signal (3). The sampling pulse signal is generated by the signal processing section 10 based on the synchronization signal (2).

FIG. 2(C) shows a signal waveform for horizontal scanning.

The illustrated signal waveform is a sawtooth waveform, and the display 11
This is for displaying an image by scanning a bright spot on the top in the direction of the horizontal line shown in the figure.

As explained above, according to the sampling method shown in FIG. 2, it is possible to sequentially and repeatedly sample images when any stress is applied to the sample to be observed 1 and display them on the ζ display 11.

In addition, in FIG. 3, the image when a specific stress is applied is displayed on the display 11 using the sampling method shown in FIG.・It can also be called a sampling method. This will be explained below.

FIG. 3(A) shows an example of the waveform of the stress application signal ■ similar to FIG. 2(A). Luminance signals (2) corresponding to substantially the same phase portions of the respective waveforms of the stress application signal (2) are sampled from the video signal (2) and are mapped to one horizontal scanning line on the display (1) from top to bottom as shown in the figure. will be displayed. In this way, a so-called line sampling method is adopted in which approximately the same phase portions of each waveform of the stress application signal (■) are sequentially displayed line by line from top to bottom on the display 11. Compared to the so-called point sampling method shown in FIG. 2, it is possible to display at an extremely high speed.

For example, using the point sampling method shown in Figure 2,
When obtaining 1000×IO00 pixels on display 11 using a repetition period of commercial frequency (50H2), 2×10′ seconds−5 hours, 33 minutes, and 20 seconds are also required. On the other hand, according to the line summing method shown in FIG. 3, it takes 20 seconds, and it is possible to display an image of a specific phase when stress is applied in an extremely short time.

FIG. 3(B) shows a pulse signal waveform for line sampling. Using the line sampling pulse signal, the first
As shown in the figure, the signal processing unit 1o extracts the luminance signal ■ at a predetermined phase (when a predetermined stress is applied) from the video signal ■, and displays it on the display 11 in association with one horizontal scanning line as shown in FIG. .

FIG. 3(C) shows an example of the horizontal scanning signal waveform. The horizontal scanning signal example is for horizontally scanning the luminance signal (■) extracted from the video signal (■) using the line sampling pulse signal shown in FIG. 3(B) so as to correspond to one horizontal scanning line on the display II. be.

FIG. 3(D) shows an example of a vertical scanning signal waveform of a sawtooth wave.

The sawtooth wave signal is used to cause the display 11 to sequentially scan horizontal scanning lines in the horizontal direction from top to bottom.

In Fig. 4, EO3 is the electron optical system of the scanning electron microscope, and the electrons emitted from the electron gun (~25K
It serves to reduce the electron beam V) using a magnetic field type lens and image the reduced minute electron beam spot on the sample 1 to be observed. In the figure, 7-1.7-2 and 7-3.7-4 indicate a vertical scanning coil and a horizontal scanning coil, respectively. This will be explained below.

The clock signal (2) generated by the mask 05C13 is supplied to the frequency dividing circuit 14, frequency-divided by l/N, and then supplied to the drive signal generator 15.

The drive signal generator 15 supplies the stress generating element 2 with a drive signal [phase] such as the sine wave shown in FIG. is applied to the sample to be observed 1. At this time, a triangular wave, a rectangular wave, etc. may be applied instead of a sine wave, if necessary.

On the other hand, the observed sample 1 is irradiated by the minute electron beam spot emitted from the EO3 mentioned above, and various signals such as secondary electrons, backscattered electrons, and X-rays are generated from the irradiated observed sample 1. ing. The generated radio waves, for example secondary electrons, are collected and amplified by the illustrated scintillation detector 8. The amplified signal is sent to a video amplifier 9
After being amplified and signal-processed by the CRT, the signal is supplied to a brightness modulation terminal of a display (CRT) 11.

Note that it is also possible to perform so-called amplitude modulation by superimposing it on the vertical scanning signal as necessary.

Further, the clock signal (2) is supplied to the horizontal scanning signal generator 16, and after being frequency-divided to 17M by the frequency dividing circuit 17, it is supplied to the vertical scanning signal generator 18. The horizontal scanning output signal and vertical scanning output signal respectively generated by the C1 horizontal scanning signal generator 16 and the vertical scanning signal generator 18 are transmitted to each horizontal scanning coil 7-3, 7-4 and each vertical scanning coil of the EO 5 and display 11. Scanning coil 7-1
7-2.

Further, the clock signal (2) is supplied to a counter 19 to generate an unblanking signal (2). The counter 19 is counted seven times each time by the drive start signal (2) supplied from the drive signal generator 15, and then starts counting the clock signal (6).
It is used as an address in the ROM (20) and generates various data written in advance at a location corresponding to the address in the form of an unblacking signal. Among the various unblanking signals generated, one having a desired phase is selected by the phase switch 21 and supplied to the blanking control section 22 . Then, the unblanking signal (2) output from the blanking control section 22 is supplied to the unblanking terminal of the display (CRT) 11. As a result, the bright spots on the display (CRT) 11 are unblended and 7-king is performed.

According to the above circuit configuration, when the frequency of the clock signal (2) generated by the mask 03C13 is f, stress is applied to the observed sample l in synchronization with the frequency of f/H. On the other hand, the horizontal scanning of the EO3 and the display 11 is performed at high speed in synchronization with r, and the vertical scanning of the EO3 and the display 11 is performed in synchronization with r/M. And unblanking of display 11 is f
/N with the same 1υ1, and the image of the specific phase is displayed on the display 11. As explained above, one period of the drive signal [phase] is divided into N on the display 11, and only the image signal of one of the divided phases is selected by the phase switch 21 and displayed on the display 11. . The embodiment shown in FIG. 4 relates to a device that obtains an image of a specific phase when a line scan is possible at high speed compared to a repetitive phenomenon, and is applicable not only to scanning electron microscopes but also to particle beams and photon beams. , a scanning device using an ultrasonic beam, etc., and an "I" V imaging device.

(Effects of the Invention) As explained above, according to the present invention, a desired stress is applied to a sample to be observed using a stress generating element, the sample to be observed is scanned with a probe, and a signal generated from the sample to be observed is generated. Since the specific phase of the stress is extracted and displayed on a display or the like, it is possible to observe and display an image of the specific phase when stress is applied using a simple device.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of one embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams illustrating the configuration of one embodiment of the present invention shown in FIG. 1,
FIG. 4 shows a block diagram of another embodiment of the present invention. In the figure, ■ is a sample to be observed, 2 is a stress generating element, 3 is a static stress applying screw, 4 is a stress applying device, 5 is an electron gun, 5-1 is an electron source, 5-2 is a Wehnelt cylinder, 5-3 is the anode, 6
is an electron lens, 7 is a scanning coil (X, Y), 8 is a scintillation detector, 9 is a video amplifier, ]O is a signal processing unit, 11 is a display, 12 is a scanning electron microscope control unit, 1
3 is a master O3C, 14 and 17 are frequency dividing circuits, 15 is a drive signal generator, 16 is a horizontal scanning signal generator, 18 is a vertical scanning signal generator, 19 is a counter, and 20 is a P-ROM.
, 21 represents a phase switch, and 22 represents a blacking control section. Patent applicant New Technology Development Corporation Patent attorney Matahiro Hase 1st Zen 2nd Sen 3rd Sen

Claims (1)

[Claims] In a dynamic observation display device that displays an image of a specific phase from an image signal obtained by periodically and rapidly changing the stress applied to the observed sample and irradiating the observed sample with a probe, A stress applying unit that changes the stress applied to the observation sample periodically and at high speed, and probe scanning that synchronously scans with a probe the observed sample whose stress is changed periodically and at high speed by the stress applying unit. a signal detection section that detects a signal generated from the observed sample by scanning with the probe scanning section; and a specific image extraction section that extracts an image of a predetermined phase from the signal detected by the signal detection section. A dynamic observation display method, characterized in that the image signal extracted by the specific image extraction section is displayed on a display.