JPH0233984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for mounting a sample for an ultrasonic microscope.

In recent years, it has become possible to generate and detect ultrahigh frequency sound waves of up to 1 GHz, making it possible to realize sound wavelengths of about 1 μm underwater, and as a result, it has become possible to obtain high-resolution sound wave imaging devices. In other words, a concave lens is used to create a focused acoustic beam, achieving a resolution as high as 1 μm.

By inserting a sample into the beam and detecting the reflected ultrasonic waves from the sample, we can elucidate the elastic properties of minute regions of the sample, or while mechanically scanning the sample in two dimensions, we can measure the intensity of this signal. By displaying this as a brightness signal on a cathode ray tube, it is possible to magnify the fine structure of the sample.

FIG. 1 is a diagram showing the main components of the ultrasound microscope. The focusing, transmission and reception of ultrasonic waves is carried out by a spherical lens 1, whose structure consists of optically polishing one side of a material made of cylindrical fused silica or the like, and then placing a piezoelectric thin film (ZnO) 2 on top of it with upper and lower electrodes 3. A pulse 5 generated from a pulse oscillator 4 is applied to the piezoelectric thin film 2 sandwiched in such a sandwich structure to generate an ultrasonic wave 6. In addition, a concave hemispherical hole with a diameter of about 0.1 mmφ to 1.0 mmφ is formed at the other end, and a medium (for example, Water) 8 is fulfilled.

Ultrasonic waves 6 generated by the piezoelectric thin film 2 propagate in the cylinder as plane waves. When this plane wave reaches the hemispherical hole, quartz (sound wave 6000 m/s) and water (sound speed
1500 m/s) causes a refraction effect, allowing focused ultrasonic waves 6 to be irradiated onto the surface of the sample 7. Conversely, the ultrasonic waves reflected from the sample 7 are collected and phased by a spherical lens, become plane waves, reach the piezoelectric thin film 2, and are converted into an RF signal 9 here. This RF signal 9 is received by a receiver 10,
Here, the signal is detected by a diode and converted into a video signal 11, which is used as an input signal for a CRT display 12.

In the apparatus configured in this way, when the sample 7 is two-dimensionally scanned within the x-y plane by the sample stage drive power supply 13, the intensity of reflection from the sample surface as the sample scans changes two-dimensionally. displayed on screen 12.

Generally speaking, a portion of ultrasound waves is reflected from the surface of an object, but a large portion of the ultrasound waves are reflected within the object, regardless of whether the object is optically transparent or not. It returns as an echo that reflects differences in density, viscosity, and defects. Ultrasonic microscopes can utilize this property to detect aspects inside a sample.

When observing a sample using an ultrasonic microscope with such characteristics, the method of fixing the sample to the sample stage 14 is as shown in FIG. - It is desirable that it be fixed parallel to the y scanning plane B. Because if sample 7
When the observation plane A of is tilted with respect to the scanning plane B of the sample stage 14 as shown in FIG. It becomes impossible to observe a uniform depth.

Furthermore, since the surface of the sample 7 is inclined, the angle of incidence of the ultrasonic waves on the sample may deviate from the normal angle, and the ultrasonic wave may not be focused at a predetermined position from the surface. Furthermore, various problems occur, such as the sound waves incident on the sample surface being converted into surface waves, resulting in interference fringes.

If the sample 7 is a flat plate whose upper and lower surfaces are parallel planes, it is easy to fix the sample 7 as shown in Figure 2 a, but let's observe the A side of the sample 7, which has a shape as shown in Figure 3. In this case, sample stage 1
It is not easy to fix the sample parallel to the A plane, and the current situation is to readjust the fixation several times to find the optimal conditions, and it takes a lot of time to set the sample. Put it away.

The present invention has been made to solve the above-mentioned problems, and is intended to provide an optimal method for mounting a sample when used on a sample stage of an ultrasonic microscope or the like.

FIG. 4 is a diagram showing the configuration of an embodiment of the present invention. A hole 16 for mounting at least one sample is provided in the sample holding plate 15, which is polished into a flat plate with upper and lower surfaces parallel to each other.

The procedure for fixing the sample 7 to the sample holding plate 15 will be described below. As shown in FIG.
Place. In this state, the sample 7 is placed in the hole 16 as shown in FIG.
It is installed so that the surface is in contact with the support stand 17. Next, as shown in FIG. 5c, the sample 7 is attached with adhesive 18,
The sample holding plate 15 is fixed. After the adhesive 18 has hardened, turn the sample holding plate 15 over and the image shown in Fig. 5d
As shown, the sample holding plate 15 and the A side of the sample 7 are fixed on the same plane.

If the sample 7 fixed to the sample holding plate 15 in the above-described manner is attached to the sample stand 14, the scanning plane of the sample stand 14 and the observation plane A of the sample 7 can be easily aligned and fixed.

By using the sample holding plate 15 in this way, the observation surface can be placed parallel to the sample stage regardless of the shape of the back surface of the sample 7.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram of the ultrasonic microscope, Figure 2 is a diagram showing the sample attachment state, Figure 3 is a diagram showing the shape of the sample, Figure 4 is a diagram showing the structure of the sample holding plate, and Figure 5. FIG. 2 is a diagram illustrating the sequence in which a sample is attached to a sample holding plate.

Claims (1)

[Claims] 1. Place a sample holding plate polished into a flat plate with upper and lower surfaces parallel to each other and having at least one hole on the polished surface of a support base having a polished flat surface, and place the observation surface of the sample on the holding plate. Insert into the hole of the plate so as to be in contact with the polishing surface of the support plate to fix the hole of the holding plate and the sample, and in this state, use the holding plate as a back plate,
A method for placing a sample for an ultrasonic microscope, characterized by placing the sample on a sample stage of the ultrasonic microscope.