JPS61200461A - Ultrasonic microscope - Google Patents

Abstract

PURPOSE:To enhance operability, by matching the surface inclination direction of a specimen with a predetermined direction by rotating the specimen so as to eliminate the inclination of an interference fringe generated by the shift of a scanning direction and the surface inclination direction of the specimen and correcting inclination in the matched state. CONSTITUTION:A specimen 7 is set to a specimen rotary stand 14b to pick up the image of said specimen 7 and the video signal from a receiver 10 and the scanning position data from a specimen stand driving part 13 are inputted to an operational controller 16. The operational controller 16 calculates angle of rotation by the interference fringe appearing in the image displayed on a display apparatus 12 and the line parallel to a scanning plane to rotate the specimen rotary stand 14b. Next, angle of inclination is calculated by the intervals between interference fringes on the image and the height difference and a piezoelectric element 17 is expanded and contracted to correct inclination.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an ultrasonic microscope, and particularly to an ultrasonic microscope that is suitable for highly accurate observation.

[Background of the invention]

The outline of the ultrasonic microscope will be explained with reference to Fig. 7 and Fig. 8@. In recent years, it has become possible to generate and detect ultrahigh-frequency sound waves using the GH2r technology, and a sound wavelength of about 1 μm can be achieved underwater, making it possible to perform imaging with high resolution using the ultrasonic waves. In FIG. 7, ultrasonic waves are focused, transmitted and received by a sonic lens 1.

The structure of the acoustic lens 1 is that one side of a material made of cylindrical fused silica or the like is optically polished +7, and the piezoelectric thin film (for example, Zn0) 2 is provided on the mounting surface in a sandwich structure with upper and lower electrodes 3. The structure is as follows.

The ultrasonic wave 6 is generated by applying the pulse 5 transmitted by the piezoelectric thin film 2# to the pulse oscillator 4#.

The other end of the acoustic lens 1 has an aperture of 0.111 mm.
A concave hemispherical hole of about 1φ to 1.0 m is formed. The distance between the hemispherical hole and the sample 7 is the ultrasonic wave 6
It is filled with a medium (for example, water) 8 for propagating the sample 7v.

In such a configuration 1, the ultrasonic wave 6 generated by the 4 m pressure membrane 2 propagates as a plane wave within the acoustic wave lens. When the plane wave reaches the hemispherical hole, a refraction effect occurs due to the difference in the propagation speed of sound between the quartz forming the sound wave lens 1 and the water acting as the medium 8, so that the upper surface of the sample 7 is reflected. The bundled ultrasonic wave 6 is I! Can shoot 6 shots. On the other hand, the ultrasonic wave emitted from the sample 7 is collected and phased by the sonic lens 1, becomes a plane wave, and reaches the piezoelectric 4 $ 2 r.
Here, the high frequency signal (hereinafter referred to as RF multiplied signal) is converted. This RF signal 9 is received by a receiver 10 and subjected to diode detection and converted into a video signal 11, which is used as an input signal for the display device 1j32. In this way, reflected ultrasonic waves from the sample 7 are obtained. At the same time, this operation is performed by scanning the sample 7 two-dimensionally within the X-Y plane by the sample stage drive unit 13C, for example, a predetermined range of the sample 7. The display device 12 is configured to display the status of 1 on the display device 12.

By the way, the sound waves used in the above-mentioned ultrasonic microscope have an ultra-high frequency of C100 MH8 to IGHz in order to obtain high resolution. Therefore, since the wavelength of the sound waves is extremely different, even if the top surface of the sample 7 is slightly inclined, the sound waves interfere with each other every λ/2 of the change 4D due to the inclination M). Interference fringes occur on the screen of No. 2 due to IF interference. For this reason, there was a problem that effective observation could not be performed due to the interference fringes. In addition, in order to solve the problem, it is necessary to take measures such as changing the shape of the sample 7 or adhering it to the block 15, which is another member.
There was also a comment that the work efficiency was very poor.

Ta.

Therefore, a means for tilting the inclination of the sample surface m in an arbitrary direction r is provided, in other words, a plurality of piezoelectric elements placed on a sample stage, and the plurality of piezoelectric elements are operated to move the sample in a direction that eliminates the interference fringes. A structure in which the angle is tilted is known. (
(For example, Japanese Patent Application Laid-Open No. 15152/1983) However, l!
In the configuration described in IT, the sample tilting means must be operated while checking the image, and no consideration was given to operability.

Further, the structure for correcting the inclination of the sample surface is usually a combination of inclination means in two directions at right angles to each other, but the inclination of the sample surface is not the same as the inclination direction of each of the above-mentioned inclination means. The correction work becomes even more complicated when there are. As a solution to this problem, there is known a structure in which a rotating means capable of rotating the sample is provided, and the direction of the tilting force on the sample is changed by rotating.

ing. (For example, Japanese Utility Model Application Publication No. 57-194060) However, there is no disclosure regarding the determination of the rotation angle of the sample, and like the above-mentioned one, no consideration was given to the operational aspects.

[Purpose of the invention]

An object of the present invention is to provide an ultrasonic microscope with good operability, in which the angle of the sample surface can be easily corrected when the sample surface is arranged at an angle.

[Summary of the invention]

In most cases, when a sample to be observed is placed on a sample stage, the upper surface of the sample, that is, the sample surface, is tilted and deviated from the scanning direction relative to the sonic lens. Therefore, when imaging is performed in the 1iff state, interference fringes occur in the image. The interference fringes are drawn obliquely due to the above-mentioned scanning direction and tilt direction. If the inclination of the interference fringes is eliminated by rotating the sample and the sample is positioned vertically or horizontally, the inclination direction of the sample coincides with the scanning direction. That is, this can be achieved by tilting the sample surface only in one direction in the scanning direction. The present invention can be seen from the above-mentioned two points, and includes a means for changing the angle of the sample surface, a means for rotating the sample surface while maintaining the angle, and an inclination of interference fringes.
means for calculating the required rotation angle of the sample by
The present invention is characterized in that the sample is rotated so that the inclination direction of the sample surface is forced in a predetermined direction, and the inclination is corrected when the inclination direction of the sample surface is aligned.

[Embodiments of the invention]

An embodiment according to the present invention will be described below with reference to FIGS. 1 to 6. In the figure, the same reference numerals as in the conventional example indicate the same members. Reference numeral 14a denotes a sample tilting table which is supported on the sample table 4 described above via a piezoelectric element 7 and a stator 8.

14b is a sample rotating table installed on the sample tilting table 14a. The planar piezoelectric elements 7 have elastic layers that change in the axial direction depending on the applied voltage, and are arranged facing each other at a predetermined interval as shown in FIG. ] 6 inputs the video signal from the receiver 10 and the scanning position data from the sample stage cooperating section 13;
The elastic layer of the f1 piezoelectric element 17 and the rotation stage of the sample rotating table 14b are calculated, and the piezoelectric element 17 and the sample rotating table 14b are
It is an arithmetic controller that controls the Here, the calculation contents of the calculation controller [6] will be explained in detail.The slope of the upper surface of the sample 7 is often disposed offset with respect to the scanning direction. Therefore, as shown in FIG. 4(a)C, the display device 1
The image displayed at 2 has interference fringes 30a.

30b is towed. At the position of this interference fringe 30a, there is a line connecting point A and point B parallel to the scanning plane, that is, a line segment on one plane on the sample surface. Furthermore, since the distances X and yI from point A to point B on the scanning axis are known, the angle θ between the scanning direction and the interference fringes 30a is θ+= tan
" The state of the sample surface corresponding to the image in this state is as shown in Fig. 4 (cJc).The inclination of the sample surface at this time is only in the scanning direction, and the inclination angle #
This is determined from the distance X between adjacent interference fringes 30a and 30b. That is, since the displacement in the height direction of the interference fringes 30a and 30b is λ/2, the inclination angle # is θ!
Find tan by λ/2・Xs.Also, i
The configuration of the tr arithmetic operation controller 16 will be explained in detail with reference to FIG.
The point A on the scanning line 20 and the point A on the scanning line 21 shown in
a position setter 16b for setting point B having the same brightness as the point; a computing unit 16c for calculating fR of the rotation angle #tortoise; and the computing unit 16c
The sample rotating table 14 is
a rotation control unit consisting of a command controller 16d that controls a;
Point B and 0 have a height difference of half a wavelength on the scanning line 22 shown in 4th FA tb), that is, a difference in two directions.
The position setting device 36e for setting the point calculates the inclination angle θ and converts it into the expansion/contraction 1 of the piezoelectric element]7 (piezoelectric cable placed at the position of dimension l in FIG. 6). In the case of angle #snow, h = lXtana.

and a sample tilt control section consisting of a command controller 162 that outputs an applied voltage that causes the sample to expand or contract by an amount corresponding to sth.

With such a configuration, its control operation will be explained. First, place the sample 7 on the sample rotating table 14b,
In this state, imaging is performed and the arithmetic controller 16 is activated.

The operation of the arithmetic controller 16 is as follows: First, the video signal from the receiver 10 and the scanning position data from the sample stage drive g5] are combined to produce an image memo! 116a. Next, point A and point B shown in Fig. 4 La) are set using the arbitrary position setter] 6b as described above, and the dimensions Xs and y are determined from the relative positions of the points, and the rotation angle aI is determined using the calculator 16C. Based on this result, a signal is output to the command controller 16d to rotate the sample rotating table 14b. ! If the operation I'iY is not completed in one go, it is repeated. By this operation, the sample surface of the sample 7 is set so that only one scanning axis thereof is parallel to the scanning plane.

Next, the tilt of the sample surface is corrected with respect to a scanning axis perpendicular to the scanning axis. first,! j& and activates the arithmetic controller 16. Then, the video signal from the receiver 10 and the scanning position data from the sample stage drive section 13 are stored in the image memory 16aC. The image memo! 716a
If two or more interference fringes appear in the image, the difference in spacing and height of each interference fringe on the image (λ/2)
c, the inclination angle #- is determined. At this time, Fig. 4(b)
Arbitrary position setter 16 sets point B and point 0, which are separated by x1 dimension.
Set from eK-, obtain the inclination angle 0 tooth from the calculator 16fC, convert the Xs dimension to the 1st dimension of the 6th factor to obtain the corrected dimension, and output the command controller]6tahe signal, and the command controller 16
The command controller 162c expands and contracts the piezoelectric element 17 to correct the inclination. If two or more interference fringes do not appear in the image, change the distance between the sonic lens 1 and the sample 7 in the Z direction while scanning in the X direction of the scanning axis with an inclination angle as shown in Fig. 6. It is sufficient to obtain the inclination angle of the surface in the so-called X-Z mode of imaging and correct it as described above. @3 The end of the interference fringe of the image shown on the display device 12IC in Figure 3 is the inclination angle and is set to the λ' point by the arbitrary position setting device 16e.

Set point B' and calculate from x/ and y/ dimensions using calculator 1.
Calculate σ' from 6flC, convert the y/dimension to the 7th dimension in Fig. 6 to obtain the corrected dimension, and output a signal to the command controller 162, which expands and contracts the piezoelectric element 17 and tilts it. Correct.

According to such a configuration, the upper surface of the sample 7, that is, the sample surface can be positioned parallel to the scanning plane relative to the sonic lens 1. Therefore, accurate observation can be performed. In the above embodiment, an example was explained in which a pressure element was used as the means for tilting the sample 7, but if the frequency of the ultrasonic wave used is low, a less precise method using a screw mechanism etc. may also be used. Effects can be obtained. In addition, the aforementioned
A similar effect can be obtained by calculating and correcting the inclination angles in the two orthogonal directions in -2 mode. Furthermore, if you want to hold any point on the image at the same position on the display device 12, you can set up a stage that can be positioned in the X and Y directions on the rotation stage J4b, and align the position with the center of rotation. If you do it, there will be no problem. [Effects of the invention] As explained above, Shinta's invention has resulted in 0. For example, even if the sample is placed with the sample surface inclined, the sample surface can be made parallel to the scanning plane and the scanning operation can be performed automatically.
Since the angle of the sample surface can be easily corrected, operability can be improved to a large degree.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the ultrasonic microscope according to the great invention, Fig. 2 is a block diagram showing details of the arithmetic controller in Fig. 1, and Fig. 3 shows an image in the X-Z mode. 4 is a diagram showing an image and the state of the sample surface during tilt correction of the sample surface, FIG. 5 is a side view of the sample support part in the ultrasonic microscope r shown in FIG. 1, and FIG. Fifth
FIG. 7 is a block diagram showing the principle of a conventional ultrasonic microscope, and FIG. 8 is a side view showing a conventional sample support situation. Spear 1 Mouth 5th Mouth Tooth Diagram Off Diagram O8 Ko

Claims (1)

[Claims] 1. A sound wave propagating body, formed at the end of this sound wave propagating body,
and a sonic lens having a predetermined focal point, and in an ultrasonic microscope that images a sample by means of turbulent sound waves from a sample placed near the focal point, a sample rotation means capable of rotating the sample while supporting it. , a sample tilting means capable of tilting the rotating surface of the sample rotation means in one scanning direction, and a sample rotation angle and a sample tilt angle calculated based on the inclination and interval of interference fringes of the imaging information. An ultrasonic microscope characterized in that it has a calculation controller that operates a tilting means.