JPS6097261A - Ultrasonic microscope - Google Patents

Abstract

PURPOSE:To make it possible to clearly know the positional relation of two images, by displaying the low magnification ultrasonic image over the wide range part of a specimen and displaying a high magnification image of the arbitrary minute region indicated in said image. CONSTITUTION:The low magnification ultrasonic image over the wide range of a specimen 5 is displayed on a first monitor 27. An operator finds out a region further desirous to high magnification observation while observes said low magnification ultrasonic image and brings a light pen 3 into contact with said position to input the coordinates thereof to a central operation processing unit 29. The cental operation processing unit 29 drives X-axis and Y-axis direction feed mechanisms 8, 9 corresponding to the input coordinates through a control circuit and performs the positional determination of the indicated part to a microscopical examination position. In the next step, a voltage applying apparatus 4 and the Y-axis direction feed mechanism 19 are driven to perform the two-dimensional scanning of the indicated region and the image signal thereof is stored in the image memory of a second scanning converter 26 and the high magnification image of a minute region is displayed on a second monitor 28.

Description

[Detailed description of the invention]

Field of the Invention The present invention relates to an ultrasound microscope, and particularly to an ultrasound microscope capable of displaying a low-magnification ultrasound image of a wide area of a sample and a high-magnification ultrasound image of a minute portion within the specimen. be. Ai Mi Soying Conventionally, an ultrasonic head equipped with an acoustic lens and a piezoelectric transducer is vibrated minutely in the X-axis direction using an excitation device, and the sample stage on which the sample is placed is moved in the Y-axis direction to generate a two-dimensional sample. C by projecting an ultrasonic beam while scanning
Ultrasound microscopes that display ultrasound images of a sample on an RT display are known. When using such an ultrasonic microscope to observe a sample with a flat surface, such as an I (11 wafer), a wide area of the sample can be displayed on a low-magnification screen, and minute parts of the sample can be further magnified. It is desirable to display the image as a high-magnification screen.In this case, first attach a low-resolution ultrasound head and display a low-magnification ultrasound image using the Y-axis and Y-transport mechanism. While observing this image, find the area to be observed in more detail, drive the Y-axis and the Y-axis direction feed mechanism to bring the desired area to the microscope position, and set the ultrasonic head to a high-resolution one. In this case, a low-magnification ultrasonic image is observed at a high magnification, and then a high-magnification image is displayed using an excitation device. Since the area to be observed is found using magnification, the positional relationship between the low-magnification image and the high-magnification image cannot be clearly known, and the area to be examined cannot be clearly specified. Positioning the area to be observed at high magnification while looking at the image at the microscope position also requires a considerable amount of troublesome operation, and also has the drawback of requiring considerable skill. If you want to observe at high magnification, after observing one area, you should switch to a low-resolution ultrasonic head again to display a wide area image of the sample, and while observing this, you should perform the next inspection at high magnification. The drawback is that the very troublesome work of searching for the site is required, and the overall inspection time is significantly lengthened.Objective of the InventionThe object of the present invention is to eliminate the above-mentioned drawbacks, and to perform low-magnification inspection of a wide range of parts of the sample. An ultrasonic image and a high-magnification ultrasonic image of any minute part within the ultrasonic image can be displayed with extremely simple operations, and the observer can clearly understand the positional relationship between the two ultrasonic images. The purpose of this project is to provide an ultrasonic microscope that can perform

[! The ultrasonic microscope of the present invention has an X-axis direction feeding mechanism and a Y-axis direction feeding mechanism that relatively move the sample and the ultrasonic head in the X-axis direction and the Y-axis direction, and a microscopic movement of the ultrasonic head in the X-axis direction. An excitation device that vibrates, an image memory that stores at least two screens of image signals obtained by receiving ultrasonic waves reflected by a sample, a coordinate input device that can specify any position in the image, and an After displaying a low-magnification ultrasonic image stored in the image memory by relatively moving the sample and the ultrasonic head using the axial and Y-axis feeding mechanisms to perform wide-range two-dimensional scanning, the low-magnification ultrasonic image is displayed. A high-magnification ultrasonic image obtained by two-dimensionally scanning a minute portion of the sample corresponding to an arbitrary position specified by the coordinate input device in the ultrasonic image using the vibration device and the Y-axis direction feeding mechanism. The present invention is characterized by comprising a display device that displays. The present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an example of an ultrasound microscope according to the present invention. Acoustic lens 1 and piezoelectric transducer 2
The ultrasonic head 8 having the above is attached to the vibration shaft 4a of the vibration device 4. A sample 5 to be inspected is placed on a sample stage 6, and an ultrasonic propagation medium such as water 7 is interposed between the ultrasonic head 8 and the sample 5. In this example, the sample stage 6 is configured with an XY table, and is configured to be movable in the X and Y axis directions by an X-axis direction feeding mechanism 8 and a Y-axis direction feeding mechanism 9. Vibration device N4 moves the ultrasonic head 3 to
It vibrates at high speed in a minute range in the axial direction, and can be constructed using, for example, a moving coil device. On the other hand, the X and Y axis direction feeding mechanisms 8 and 9
The ultrasonic head 8 is moved over a wide range, and can be constructed using, for example, a linear drive mechanism including a motor and a lead screw. In this example, an X-axis direction moving mechanism 10 is further provided to move the sample stage 6 in two directions, which are the projection directions of the ultrasonic beam, so that the distance between the ultrasonic head 8 and the sample 5 can be adjusted. Configure it as follows. Furthermore, the sample stand 6 is supported by a goose-nose meter, and the inclination of the sample stand can be adjusted by rotating it around the Y-axis and the Y-axis. This mechanism is omitted from the characteristic patent, and will be described in detail later. Next, the electric circuit portion of the ultrasonic microscope of the present invention shown in FIG. 1 will be explained. A nozzle-like high-frequency pulse signal synchronized with the control signal from the control circuit 11 is generated from the high-frequency generator 12, amplified by the buffer amplifier 18, and then added to the piezoelectric transducer 2 of the ultrasonic head 8 via the circulator 14. Then, the burst high-frequency pulse signal is converted into an ultrasonic wave corresponding to the burst frequency. The ultrasonic waves are focused by an acoustic lens 1 to project an ultrasonic beam onto a sample 5, and the reflected waves are collected by the acoustic lens 1 and converted into electrical signals by a piezoelectric transducer 2. This received signal contains illegal unnecessary signals such as ultrasonic waves that have been internally reflected multiple times in the acoustic lens 1 and burst-like high-frequency pulse signals leaking from the circulator 1.
This is guided to the gate 15, and a gate signal having a predetermined timing from a blanking circuit to be described later is used to
Only the received signal corresponding to the direct reflected wave from the is extracted. This signal is amplified by a high frequency amplifier circuit 7 via an attenuator 16, and then introduced to a mixer 18 where it is mixed with a local oscillation frequency signal from a local oscillator 19 and converted into an intermediate frequency signal. This intermediate frequency signal is supplied to a detector 21 via an intermediate frequency amplifier 20, where it undergoes envelope detection, and then
It is input to the blanking circuit 22. The blanking circuit 22 supplies the gate 15 with a gate signal that extracts only the received signal corresponding to the direct reflected wave from the sample 5. The output of the blanking circuit 22 is subjected to peak detection by a peak detection circuit 28, and the detected output signal thus obtained is guided to one of the first and second scan converters 25 and 26 via the limiter 24. These scan converters are supplied with synchronization information signals related to the X-axis scanning period of the vibration device 4 and the synchronization information signals related to the X-axis and Y-axis scanning periods of the sample stage 6 from the control circuit 11. The output image signals from the IJ transmitter 24 are sequentially stored at a predetermined position in the image memory at -0 o'clock. This signal is read out repeatedly according to the television scanning cycle, and all synchronization information is added to it, converted to a television signal, and supplied to the first and second television image monitors 27 and 28 for image reproduction. Acquired sonic microscope images. Furthermore, control circuit 1
1. First and second scan converters 25 and 2
Central processing unit 29 and light pen 80 for controlling 6
and. In the present invention, as described above, the first and second scan converters 25 and 26 are provided so that images for two screens can be stored. That is, a low-magnification image signal is first extracted and stored in the first scan converter 25, and a low-magnification ultrasonic image of a wide area of the sample 5 is extracted and stored in the first scan converter 25.
It is displayed on the monitor 27. While viewing this low-magnification ultrasonic image, the operator searches for a region to be observed at higher magnification, places the light pen 80 on the corresponding region, and inputs its coordinates to the central processing unit 29. The central processing unit drives the X-axis and Y-axis direction feeding mechanisms 8 and 9 via the control circuit 11 according to the input coordinates, and the light pen 8
The region specified by 0 is positioned at the speculum position. Next, the vibrating device 4 and the Y-axis direction feed mechanism 9 are driven to two-dimensionally scan the designated area, and the image signal is stored in the image memory of the second scan converter 26, and the high-magnification ultrasonic wave of the minute area is The image is displayed on the second monitor 28. In this way, it is possible to display an ultrasonic image of a wide area of the sample and an enlarged ultrasonic image of any minute area within it, making it possible to clearly understand the positional relationship between the two observation areas. . Furthermore, by leaving the image signal stored in the first scan converter 25 as it is and specifying another minute region using the light pen 80, a new high-magnification ultrasound image of this region is displayed on the second monitor 28. can do. In this case, the region designated by the light pen 30 may be displayed on the first monitor using, for example, a cursor. As described above, according to the present invention, low-magnification images and high-magnification images can be displayed, which can be mainly controlled by the computer forming the central processing unit 29. Next, the operation of each part will be explained in detail, focusing on the operation of the central processing unit 29. Figure @2 shows a flowchart when obtaining a low-magnification ultrasound image. When obtaining a low-magnification ultrasonic image, the vibrating device 4 is not driven as described above, and the sample stage 6 is moved by the X-axis and Y-axis direction feeding mechanisms 8 and 9.
Dimensional scanning is performed; in this case, first, the position and range of two-dimensional scanning are designated. For example, as shown in FIG. 3, a point P in a range F to be scanned two-dimensionally. and Po coordinates (X6 + YO) and (XI r Yl
), then input these coordinates by operating the keys on the keyboard. At this time, the speculum axis of the ultrasound head a is at point P. (XO, YO), drive the X-axis and Y-axis direction feeding mechanisms 8 and 9 to move the speculum i11+ to point P. (Xo+Y□). When the initial settings are completed in this way, the high-frequency pulse generator 12 is driven to project and emit ultrasonic pulses toward the sample 5, the reflected pulses are received, and the corresponding image signals are sent to the gate 15.
and stores it in the corresponding address position of the image memory of the first scan converter 25. Next, drive the X-axis direction feed mechanism 8 to move the sample stage 6 by one step in the X-axis direction, and perform the same operation to store the image signal at the next address position in the image memory as seen in the X direction. . Repeat this operation until X −X,
Image information for 1 line and 2 minutes is sequentially stored in one line of the image memory of the first scan converter 25. Next, when X-X□ is reached, the X-axis direction feed mechanism 8 is driven to return to the X-Xo position, and the Y-axis direction feed mechanism 9 is driven to move the sample stage 6 one step in the Y-axis direction. After that, the above-described operation is repeated to store the image signal of the second line in the second line of the image memory of the first scan converter 25. By repeating this operation until Y - Y, one screen worth of image signals representing the wide range FL in FIG. 8 is stored in the image memory of the first scan converter 25. - Figure 4 is a flowchart showing the operation when obtaining a high-magnification ultrasound image. While observing the low-magnification image displayed on the first monitor 27 as described above, the user places the tip of the light pen 80 at the center of a desired area and activates the switch provided on the light pen. As a result, as shown in FIG. 8, the coordinates (Xm
, Ym) are input to the central processing unit 29. In this case, the field of view size (DXW) is input in advance by operating keys on the keyboard. That is, the amplitude (scanning width) W in the X-axis direction by the vibration device 4 and the scanning width in the Y-axis direction by the Y-axis direction feed mechanism 9 are input. This size can be switched, for example, in four stages. The central processing unit 29 receives the above-mentioned input data D,
Based on W, Xm, Ym, the point P; , P/,
The coordinates of / and Pm are calculated as follows. Next, the X-axis and Y-axis direction feeding mechanisms 8 and 9 are driven via the control circuit 11 to move the speculum axis of the ultrasound head 8 to the point P.
Match m. After making the initial settings in this way, the vibration device 4 is driven to vibrate the ultrasonic head 3 in the X-axis direction, the ultrasonic head 3 emits an ultrasonic beam to the sample 5, and the reflected wave is received. The image data is converted into an electrical signal, processed appropriately, and stored in the image memory of the second scan converter 26. That is, the vibration device 4 moves the ultrasonic head 8 to an amplitude W.
When the position xm is detected twice after making one reciprocation with make it go back and forth. The image signal obtained by two-dimensionally scanning the minute portion FH of the sample by sequentially repeating the above-mentioned operation until Y - Y,' can be stored in the image memory of the second scan converter 26. In this case, the second monitor 28
The enlarged image of the minute part FH displayed above is on the first monitor 27.
The light pen 80 can be used to arbitrarily select from among the low magnification images of the wide area FL displayed above.
The positional relationship between both images can be clearly known. Further, if it is desired to display a high magnification image of another minute part within the wide area FL, it is only necessary to newly designate the position using the light pen 30, and the operation is very simple. As mentioned above, it is necessary to use a low-resolution ultrasound head when displaying a low-magnification image of a wide area of the sample, and a high-resolution ultrasound head when displaying a high-magnification image of a minute area. . This can be done by replacing the ultrasound head each time, but in this example the same ultrasound head can be used to display both low and high magnification images. This will be explained below. FIG. 5A shows the positional relationship between the ultrasonic head 8 and the sample 5 when obtaining a low-magnification ultrasonic image. In this case, the ultrasonic beam emitted from the ultrasonic head 8
The distance 10 is adjusted such that it is focused within the sample 5 so that a large diameter ultrasonic spot is projected onto the surface of the sample 5, as shown in FIG. 6A. By selectively extracting the reflected waves from the surface of the sample 5, a low-magnification ultrasonic image can be obtained. On the other hand, when obtaining a high-magnification ultrasonic image, the distance l between the two is set to 6 so that the ultrasonic beam emitted from the ultrasonic head 8 is precisely focused on the surface of the sample 5, as shown in FIG. 5B. Adjust the distance to be longer than the distance 10 shown in Figure A. In this case, as shown in Figure 6B, the ultrasonic beam spot with the smallest diameter is projected onto the sample surface, and high-resolution scanning is performed, resulting in a high-magnification ultrasonic image. will be displayed. The distance between the ultrasonic head 3 and the sample 5 can be adjusted in this way by driving the Y-axis direction feeding mechanism 10 shown in FIG. As described above, in the ultrasonic beam of this example, the sample stage 6 is supported by a goniometer so that the Y-axis and the inclination in the Y-axis direction can be adjusted. That is, as shown in FIG. 7, the goniometer 81 includes an X-axis adjustment motor 32 that rotates the sample stage 6 around the Y-axis to adjust the inclination in the X-axis direction, and an X-axis adjustment motor 32 that rotates the sample stage 6 around the Y-axis. Y-axis direction adjustment motor 3 that adjusts the Y-axis direction inclination by
3 and drive these motors appropriately to move the sample stage 6.
The surface of the sample placed above is perpendicular to the projection direction of the ultrasound beam. The operation will be explained below with reference to FIG. FIG. 8 shows a flowchart for adjusting the inclination in the X-axis direction. First, point P in FIG. (Xo,
Yo) and P, (X, , Y, ) are input, and the Y-axis and Y-axis direction feed mechanisms 8 and 9 are driven to move the sample stage 6 to point P. Move to position (Xo+YQ). Here, ultrasonic waves are emitted and the intensity of the reflected waves from the sample surface is detected. FIG. 9 shows the position 2 of the ultrasonic head 8 in the Z direction on the horizontal axis and the intensity V of the reflected wave on the vertical axis, indicating the focal position where the ultrasonic beam is focused on the sample surface. At 2°, the intensity is the maximum value V. becomes. Therefore, focus adjustment is performed to obtain the maximum intensity V. Remember. Next, the X-axis direction feed mechanism 8 is driven to move one step in the X-axis direction, and the reflection intensity V at that position is measured. This measured intensity V is the maximum intensity V. If the value is smaller than the value obtained by subtracting the preset value α, the sample stage is moved again.
Move the step. In this way, detection is performed sequentially, and the point (Xn
+ YO), the reflection intensity vn is V. If it becomes smaller than -α, it is determined that there is an unacceptable inclination, and the position Mzn in the Z-axis direction at this position is determined. From these values, the tilt angle α is tilted by the angle α in the opposite direction by driving the rotor 32. The inclination in the X-axis direction can be corrected by sequentially performing the above-described operations until X-X□. Next, set the adjustment table 6 to point P. Move it to (Xo, Yo),
Y about the Y-axis direction. By performing similar operations in the range from Yl to Yl, the Y-axis adjustment motor 88 can be driven to correct the Y-axis tilt. In this way, the tilt can be corrected in both the X-axis and Y-axis directions, and a more accurate ultrasound image can be displayed. The present invention is not limited to the embodiments described above, and can be modified and modified in many ways. For example, in the example described above, the first and second monitors were provided to display a low-magnification ultrasound image and a high-magnification ultrasound image, respectively. Alternatively, a low magnification image may be displayed on one side, and a high magnification image may be displayed on the other side. Also, in the example above,
Although a light pen was used as a means for inputting the coordinates of a minute site, it is also possible to input the coordinates using a cursor displayed on the monitor screen. Furthermore, by increasing the number of scan converters and monitors, it is also possible to display ultrasound images of two or more minute regions. Further, in the above-mentioned example, the X-axis and Y-axis direction feeding mechanisms move the sample stage, but either or both of these may move the ultrasonic head. According to the present invention, a low-magnification ultrasonic image of a wide area of a sample is displayed, the position of an arbitrary minute part therein is specified by an input device, and a high-magnification image of this minute part is displayed. , the positional relationship between the two images can always be clearly known, and accurate and quick observation can be performed. Furthermore, simply by newly specifying the position of a minute part, a high-magnification image of that part can be displayed, making the operation extremely simple.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of an example of the ultrasound microscope of the present invention, Figure 2 is a flowchart showing the operation when displaying a low-magnification ultrasound image, and Figure 8 is a low-magnification image and a high-magnification image. Figure 4 is a flowchart showing the operation when displaying a high-magnification ultrasound image, and Figures 5A and B are low-magnification and high-magnification ultrasound images using the same ultrasound head. Figure 6A and B are diagrams showing the positional relationship between the ultrasound head and the sample when displaying a sound wave image, and Figure 76 is a diagram showing the spot of the ultrasound beam projected onto the sample surface in that case. is a perspective view showing the goniometer mechanism that adjusts the inclination of the sample stage, Fig. 8 is a flowchart showing the operation of inclination adjustment, and Fig. 9 shows the relationship between the position of the ultrasonic head and the reflection intensity when adjusting the inclination. This is a graph showing. 1... Acoustic lens 2... Piezoelectric transducer 8... Ultrasonic head 4... Vibration device 5... Sample 6... Sample stage 8... X-axis direction feeding mechanism 9... Y-axis direction feeding mechanism 10... Z-axis direction simultaneous feeding mechanism, 11... Control circuit 25
．． 26...@1. 2nd scan converter 27.28
...First. Second monitor 29...Central processing unit 80...Light pen. Patent Applicant: Olympus Optical Industry Co., Ltd. Figure 2 Figure 3 Figure A 5 Figure 9 Procedural Amendment May 8, 1982 1. Indication of the Case 1988 Patent Application No. 204719 2. Title of the Invention Ultrasonic Microscope 3, Relationship with the Corrector Case Patent Applicant (037) Olympus Optical Industry Co., Ltd. Telephone (581)
No. 2241 (representative), ``Blanking circuit to be described later'' on page 7, line 19 of 1 specification is corrected to ``control circuit 1''. 2, page 8, lines 8-10, “This-m-supply.”
A control signal is supplied from the control circuit 11 to the blanking circuit 22 to block unnecessary signals leaking from the gate 15 and extract only the received signal corresponding to the direct reflected wave from the sample 5. Of the 8 drawings to be corrected, Figures 1, 2, and 4 are corrected as shown in the attached corrected drawings. Figure 2 □ Figure 4

Claims (1)

[Claims] L An X-axis direction feeding mechanism and a Y-axis direction feeding mechanism that move the sample and the ultrasonic head in pairs in the X-axis direction and the Y-axis direction by 4' fl, and an excitation that causes minute vibrations of the ultrasonic head in the X-axis direction. an image memory that stores image signals obtained by receiving ultrasonic waves reflected by a sample for at least two screens; a coordinate input device that can specify any position in the image; The sample and the ultrasonic head are moved relative to each other by the feeding mechanism in the Y-axis direction, a wide range of two-dimensional scanning is performed, and a low-magnification ultrasonic image stored in the image memory is displayed. A high-magnification ultrasonic image obtained by two-dimensionally scanning a minute portion of the sample corresponding to an arbitrary position specified by the coordinate input device in the image using the vibration device and the Y-axis direction feeding mechanism is displayed. An ultrasound microscope characterized by comprising a display device.