JPS6188144A - Ultrasonic microscope - Google Patents

Abstract

PURPOSE:To detect an observing position easily even if a sample is removed from an ultrasonic microscope by forming a means for forming a flaw which is a mark on a part of the sample in a visual field of the microscope. CONSTITUTION:When an ultrasonic wave 6 generated by applying a pulse 5 from a pulse oscillator 4 to a piezoelectric thin film 2 is transmitted through a cylinder of a spherical lens 1 as a plane wave and reached to a semispherical hole, refraction is generated due to the difference between the sound speeds of quartz and water 8 and the covered ultrasonic waves are irradiated on the surface of the sample 7. The reflected ultrasonic wave is reached to a piezoelectric thin film 2 through the spherical lens 1, an RF signal 9 is received by a receiver 10 and the intensity of the reflection from the surface of the sample 7 which may be generated in accordance with scanning by a sample board driving power supply 13 is displayed on a CRT surface 12. On the other hand, a contact stylus 15 fitted to a fitting board 14 is brought into contact with an optional position on the surface of the sample 7 and a high-voltage pulse is applied to a piezoelectric oscillator 17, so that the point of the stylus 15 is oscillated and the mark can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an ultrasonic microscope equipped with a means for mechanically scanning between an acoustic lens and a sample.

[Background of the invention]

In recent years, it has become possible to detect the generation of ultrahigh-frequency sound waves up to I GHz, making it possible to realize sound wavelengths of approximately 1 μm underwater, and as a result, it has become possible to obtain high-resolution sonic imaging devices. Ta. That is, a concave lens is used to create a focused sound wave beam, achieving a high resolution of 1 μm.

By inserting a sample into the beam and detecting the reflected ultrasound waves from the sample, we can elucidate the elastic properties of the microscopic region of the sample.
Alternatively, it was shown in JP-A-50-116058 that by mechanically scanning a sample in two dimensions and displaying the intensity of this signal as a brightness signal on a cathode ray tube, it is possible to enlarge the fine structure of the sample. ing.

FIG. 1 is a diagram showing the main components of the ultrasound microscope. The focusing, transmission and reception of ultrasonic waves is performed by a spherical lens 1, and its structure consists of optically polishing one side of a material made of cylindrical molten stone, etc., and piezoelectric thin films (ZZ○) 2 are placed on top and bottom electrodes. A pulse 5 generated from a pulse oscillator 4 is applied to the piezoelectric thin film 2 sandwiched between the two piezoelectric thin films 2 having a sandwich structure as described above, thereby generating an ultrasonic wave 6. In addition, the other end has a diameter of 0,1 mm mφ~1,0 m
A concave hemispherical hole of about mφ is formed, and a medium (for example, water) 8 for propagating the ultrasonic wave 6 to the sample 7 is filled between the hemispherical hole and the sample.

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 (velocity of sound 6000 m/s) and water (velocity of sound 1500 m/s)
Due to the difference in sound speed with s ), a refraction effect occurs, and the superζ? Wave 6 can be irradiated. 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. The RF signal 9 obtained by the ultrasonic transducer having such a sonic lens is received by the receiver 10, which performs diode detection and generates the video signal 1.
1 and used as an input signal for the CRT display 12. When the sample 7 is scanned two-dimensionally within the x-y plane by the sample stage drive power supply 13, the The intensity of reflection from the sample surface during scanning is displayed two-dimensionally on the CRT surface 12.

This ultrasonic microscope is used in the medical and biological fields to observe the structure and tissue of living cells, as it does not require drying the sample like an electron microscope or dyeing it like an optical microscope. There is. In addition, it is expected to have a wide range of applications in the fields of engineering and science, such as observation of metal structures, identification of substances, and non-destructive inspection of small areas mainly for observation of the subsurface of semiconductor devices.

Such an apparatus is often used to detect defects, inclusions, grain boundaries, etc. present inside a sample whose surface has been optically polished. However, there are many requests to use other observation methods to confirm whether the images depicted by an ultrasonic microscope accurately reflect the information inside the sample.

For example, a case may be made in which a portion thought to be a precipitate is etched using an ultrasonic microscope, then observed using an optical microscope, and the results of the two methods are compared.

In such a case, etching the same area observed with an ultrasonic microscope and then etching it with an optical microscope will waste a lot of time searching for that field of view. Especially when the sample surface is optically polished, it is almost impossible to find the same spot because there are no landmarks on the sample surface.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a means by which the observed position can be found even after removing a sample from an ultrasonic microscope.

[Summary of the invention]

In order to solve this problem, the present invention is characterized in that it is provided with a means for making a mark or the like on a part of the sample within the field of view of the ultrasonic microscope.

The present invention will be described in detail below based on the figures.

[Embodiments of the invention]

Figure 2 shows the configuration of an embodiment of the present invention, in which a mounting base 1 is mounted at a predetermined location on a mechanical scanning sample stage or a spherical lens.
The tip of the stylus 15 attached to the stylus 4 is moved to any desired location on the surface of the sample mounted on the sample stage using the knob 16 or other position adjustment mechanism, and is brought into contact with a predetermined position on the sample surface. It is now possible to do so.

In addition, a piezoelectric vibrator 17 is provided in a part of the stylus, and when the expansion and contraction caused by applying a high voltage pulse to the piezoelectric oscillator 17 is transmitted to the stylus 15, the tip of the stylus 15 vibrates, making the sample hard. You can easily mark things.

Above, we have described the method of making marks on the sample surface using a stylus, but an alternative method is to irradiate a narrowly focused laser beam onto the sample surface from the direction in which the stylus is introduced, and to localize the irradiated area. It is also possible to melt the material and write the mark on it. However, in this case, it is necessary to remove the medium between the spherical lens and the sample.

〔Effect of the invention〕

By providing such a simple mechanism in an ultrasonic microscope, it becomes possible to easily find the same field of view.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a conventional ultrasound microscope, and FIG. 2 is a diagram showing the configuration of an embodiment of the present invention.

Claims (1)

[Claims] 1. An ultrasonic transducer equipped with a sonic lens having a predetermined focus formed at the end of a sound wave propagation body, a sample stage that holds a sample near the focal point, and an upper sample stage that drives and scans. In an ultrasonic microscope that photographs the sample using disturbed sound waves from the sample, inserting a mark on the sample stage at any location within the observation field on the surface of the sample. An ultrasonic microscope characterized by comprising means for