JPH0650948A - Ultrasonic probe and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an ultrasonic probe and its manufacturing method which can measure anisotropy of a specimen accurately and can specify an observation surface. CONSTITUTION:Spherical surface shaped curved surfaces 3a and 3b form curved surfaces in 1/4 spherical surface shape and a cylindrical curved surface 4 forms a cylindrical shape running in X-axis direction in figure. An ultrasonic wave 7A which is generated from a position corresponding to an upper electrode 11 by a transmitter reaches from the cylindrical curved surface 4 to a specimen surface 20 and echoes of ultrasonic wave which are reflected by the specimen surface 20 pass through the cylindrical curved surface 4 again, become ultrasonic waves 7B, and are received by the upper electrode 11. On the other hand, an ultrasonic wave 5A which are generated from a position corresponding to an upper electrode 12 reaches the specimen surface 20 from the spherical surface shaped curved surface 3a and generates a leakage acoustic wave 14 on the surface of the specimen surface 20 and then the leakage surface acoustic wave 14 is received as an upper electrode 10 as an ultrasonic wave 6B passing through a spherical surface shaped curved surface 6B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe, and more particularly to an ultrasonic probe suitable for observing the surface and the inside of a sample and further measuring the surface physical properties of the sample, and a method for manufacturing the same. Regarding

[0002]

2. Description of the Related Art An ultrasonic microscope for detecting anisotropy around the Z axis (direction coincident with the emission direction of an ultrasonic beam) of acoustic characteristics of a solid body by using an ultrasonic beam focused linearly, For example, it is disclosed in JP-A-58-9063.
The ultrasonic microscope disclosed in this document, particularly the ultrasonic probe, will be described with reference to FIGS. 13 to 16.

In FIG. 13, the lower electrode 102, the piezoelectric body 103, and the upper electrode 10 are provided on the upper surface of the acoustic lens 101 in the figure.
4 and 4 are arranged in a laminated state. The acoustic lens 101 acts as a solid sound field medium that transmits ultrasonic waves generated by the piezoelectric body 103. When a voltage in a burst or pulse state is applied to the upper electrode 104 by the oscillator 105, a plane wave-shaped ultrasonic wave 106 is generated from the piezoelectric body 103 by the acoustic lens 10.
It is radiated to the inside of 1.

At the lower end of the acoustic lens 101 in the figure, there is provided a lens surface 107 which is optically polished into a cylindrical concave surface, and on which a quarter wavelength antireflection film 108 is formed. The ultrasonic wave 106 is focused on the lens surface 107 and is applied to the sample 110 via the liquid sound field medium 109. The shape of the lens surface 107 and the positional relationship between the lens surface 107 and the main body of the acoustic lens 101 are clear from the bottom view shown in FIG.

The focused beam of the ultrasonic wave 106 obtained by the acoustic lens 101 is a linear focused ultrasonic beam which is narrowed down to about one wavelength in the X direction and not narrowed in the Y direction in FIG. . The X, Y, and Z directions are shown in FIG.

The ultrasonic waves applied to the sample 110 are reflected. This reflected wave again passes through the acoustic lens 101 and is detected by the piezoelectric body 103. The detected signal is sent to the receiver 112 via the circulator 111 and then
Signal processed.

The above-mentioned ultrasonic microscope is used in the apparatus configuration shown in FIG. In this device, a Z-axis direction moving device 113 for arranging the sample 110 is provided for the ultrasonic microscope. The sample 110 is observed with an ultrasonic microscope, and the measurement data is recorded in the recording device 114. At this time, the position of the sample 110 is changed by the moving device 113 so as to approach the acoustic lens 101 side. 115 is a moving device 1
The data relating to the movement amount of 13 is converted and the recording device 114
It is a converter to give to.

By performing the above measurement, between the distance in the Z-axis direction and the measurement output obtained by the acoustic microscope,
As shown in FIG. 16, the measurement curve 116 having periodicity
Can be obtained. This curve is called the V (z) curve. When the period Δz of this curve is obtained, the velocity of the leaky surface acoustic wave in the Y direction of the substance forming the sample can be obtained by calculation using the period Δz. This method
It is effective and widely used for the quantitative measurement of acoustic characteristics of solids, particularly for the quantitative measurement of acoustic characteristics of solids having acoustic anisotropy.

[0009]

However, the above-mentioned known technique has the following problems. Generally, when taking a V (z) curve with a lens having a circular cross section, the number of periodic peaks and valleys shown in FIG. 16 is limited by the radius (correctly, the working distance as a probe). It is necessary to increase the number of peaks and troughs in order to obtain leaky surface acoustic waves with high accuracy when measuring the anisotropy of the acoustic properties of solids. Therefore, it is necessary to increase the lens diameter and increase the working distance. There is. However, even if the diameter of the lens is increased, the angle itself at which the leaky elastic wave is generated does not change. Therefore, the working distance is not extended so much and is limited in order to secure this critical angle.

Further, it is difficult to specify the measurement location of the surface to be observed.

Further, in one measurement, V in a certain direction is used.
Only the (z) curve can be taken, and in order to measure a plurality of directions, for example, the directions of two orthogonal axes, the probe had to be moved and measured again.

An object of the present invention is to provide an ultrasonic probe capable of accurately measuring the anisotropy of a sample and specifying an observation surface, and a method for manufacturing the ultrasonic probe.

Another object of the present invention is to provide an ultrasonic probe capable of simultaneously measuring anisotropy in two orthogonal directions and a method for manufacturing the ultrasonic probe.

[0014]

In order to achieve the above object, the present invention has an acoustic lens having a piezoelectric body arranged at one end and a lens surface formed at the other end. In the ultrasonic probe to obtain information of the sample by applying a voltage to the piezoelectric body by the positioned electrode means to generate an ultrasonic wave, focusing the ultrasonic wave on the lens surface and irradiating the sample to the sample,
The lens surface has at least one pair of opposed spherical curved surfaces and one cylindrical curved surface located between the opposed spherical curved surfaces and having a flat longitudinal cross section. The electrode means is arranged so that the ultrasonic waves reach the positions of the curved surface and the cylindrical curved surface.

Preferably, the electrode means is composed of an upper electrode and a lower electrode, and the upper electrode is provided in a row in the major axis direction and the minor axis direction of the lens surface, and an electrode row in the major axis direction. And the electrode rows in the minor axis direction are arranged so as to be orthogonal to each other on the piezoelectric body.

Further, the present invention has an acoustic lens having a piezoelectric body arranged at one end and a lens surface formed at the other end, and a voltage is applied to the piezoelectric body by electrode means located above and below the piezoelectric body. In the ultrasonic probe, which generates ultrasonic waves and focuses the ultrasonic waves on the lens surface to irradiate the sample to obtain information on the sample, the lens surface includes two cylindrical curved surfaces orthogonal to each other. It is provided at four locations on both ends of a cylindrical curved surface and faces each other.
A pair of spherical curved surfaces, the electrode means is composed of an upper electrode and a lower electrode, and the upper electrodes are arranged in a row in the same direction as the two cylindrical curved surfaces on the piezoelectric body. It is arranged so as to be orthogonal.

Preferably, in the ultrasonic probe,
The acoustic lens is silicon.

Preferably, in the ultrasonic probe, SiO ₂ obtained by thermally oxidizing silicon is used for the acoustic matching layer of the acoustic lens.

Further, in order to achieve the above object, the present invention has an acoustic lens having a piezoelectric body arranged at one end and a lens surface formed at the other end, and a voltage is applied to the piezoelectric body to generate an ultrasonic wave. In the method of manufacturing an ultrasonic probe in which the ultrasonic wave is focused on the lens surface to irradiate the sample to obtain the information of the sample, the acoustic lens 1 is formed by etching using an elliptical etching mask. A lens surface having a pair of opposed spherical curved surfaces and a cylindrical curved surface located between the opposed spherical curved surfaces and having a flat longitudinal cross section is formed.

Further, according to the present invention, there is provided an acoustic lens having a piezoelectric body arranged at one end and a lens surface formed at the other end, and a voltage is applied to the piezoelectric body to generate an ultrasonic wave. In the method of manufacturing an ultrasonic probe, which focuses light on a lens surface and irradiates a sample to obtain information on the sample, the ultrasonic lens is orthogonal to the acoustic lens by etching using an etching mask having two orthogonal oval shapes. Two cylindrical curved surfaces,
A lens surface having two sets of opposing spherical curved surfaces provided at four positions on both ends of the cylindrical curved surface is formed.

[0021]

In the present invention configured as described above, the spherical curved surfaces facing each other on the lens surface are arranged so as to be separated by sandwiching the cylindrical curved surface, so that the distance traveled by the leaky elastic wave is increased to the focal position. The working distance of is increased. Further, since the lens surfaces are the spherical curved surface and the cylindrical curved surface that face each other, the ultrasonic waves are also focused in the minor axis direction of the lens surface.
Therefore, the amount of ultrasonic waves input per unit area increases, the power of ultrasonic waves incident on the sample surface increases, and a strong leaky elastic wave is generated. Further, by using the spherical curved surface of the lens surface to focus the ultrasonic waves in both the long axis and the short axis to form the focal point, image processing is performed based on the measured values of the plural focal points to obtain a two-dimensional image.

Further, by arranging the upper electrodes so that the electrode rows are orthogonal to each other on the piezoelectric body in the major axis direction and the minor axis direction of the lens surface, V ( z) Measure the curve.

Furthermore, in the present invention, by providing a lens surface having two orthogonal curved surfaces and two sets of spherical curved surfaces facing each other at four positions at both ends, the operation up to the focus position in the two orthogonal axis directions is performed. The distance increases. Therefore, the amount of ultrasonic waves input per unit area in the two orthogonal directions becomes large, the power of the ultrasonic waves incident on the sample surface becomes strong, and a strong leaky elastic wave is generated.

[0024]

Embodiments of the present invention will be described below with reference to FIGS. A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of the ultrasonic probe of the present embodiment. In FIG. 1, the ultrasonic probe 50 includes a lens body 1, upper electrodes 10 to 12, a piezoelectric film 9, and one lower electrode 8.

The lens body 1 is made of single crystal silicon and has a lens surface 2 at the bottom. The lens surface 2 is formed by etching a single crystal silicon material.
It is composed of one spherical curved surface 3a and 3b and a cylindrical curved surface 4. The spherical curved surfaces 3a and 3b are curved surfaces having a shape of 1/4 spherical surface and are represented by 1/4 circle in the figure. The cylindrical curved surface 4 is in the shape of a cylinder running in the X-axis direction in the figure, is represented by a straight line in the figure, and the cross section in the direction perpendicular to the X axis, that is, the short-axis cross section forms a U-shape.

On the upper surface of the lens body 1, a lower electrode 8, a piezoelectric film 9 thereon, and an upper electrode 10 to 10 thereon.
12 are formed. Each of the upper electrodes 10 to 12 is connected to an output terminal of an ultrasonic wave oscillator used for measurement and an input terminal of a receiver for receiving an ultrasonic wave echo from the sample surface 20. Furthermore, the receiver is connected to an image processing device that performs two-dimensional imaging based on the measurement data.

Of the upper electrodes 10 to 12, the upper electrode 10
And 12 are ultrasonic waves 6 passing through the spherical curved surfaces 3b and 3a.
The upper electrodes 11 are arranged at positions corresponding to A, 6B and 5A, 5B, and the upper electrodes 11 are arranged at positions corresponding to the ultrasonic waves 7A passing through the cylindrical curved surface 4. That is, the ultrasonic wave 7A generated from the position corresponding to the upper electrode 11 by the transmitter reaches the sample surface 20 from the cylindrical curved surface 4, and the echo of the ultrasonic wave reflected on the sample surface 20 passes through the cylindrical curved surface 4 again. , Ultrasonic waves 7B are received by the upper electrode 11. On the other hand, the ultrasonic wave 5A generated from the position corresponding to the upper electrode 12 reaches the sample surface 20 from the spherical curved surface 3a to generate the leaky surface acoustic wave 14 on the surface of the sample surface 20, and the leaky surface acoustic wave 1
4 is received by the upper electrode 10 as an ultrasonic wave 6B passing through the spherical curved surface 3b. Similarly, the ultrasonic wave 6A generated from the position corresponding to the upper electrode 10 is received as the ultrasonic wave 6B by the upper electrode 12 in the route opposite to the above-described route.

FIG. 2 is a bottom view of the ultrasonic probe 50 seen from the lens surface side. Lens surface 1 having a square shape
There is a flat portion 13 having a circular outer edge portion in the central portion, which is raised from the outer edge portion of, and spherical curved surfaces 3a and 3b and a cylindrical curved surface 4 are provided in a shape cut into the flat portion 13.
The opening 15 has an oval shape.

FIG. 3 is a top view of the ultrasonic probe 50 as seen from the electrode side. A circular lower electrode 8 is arranged on the lens surface 1, a piezoelectric film 9 in the shape of a concentric circle is formed on the lower electrode 8, and small circular upper electrodes 10 to 12 are arranged in the range of an opening 15 indicated by an imaginary line. Are arranged in a line in the X-axis direction.

Next, the operation of this embodiment having the above construction will be described with reference to FIGS. FIGS. 4A and 4B are diagrams showing the generation / detection paths of ultrasonic waves in the present embodiment and the generation / detection paths of ultrasonic waves in the related art in comparison. FIG. 4A shows ultrasonic waves in this embodiment, and FIG. 4B shows ultrasonic waves in the conventional technique.

In FIG. 4A, the ultrasonic wave 6A generated from the position corresponding to the upper electrode 10 reaches the spherical curved surface 3b, and the leak elastic wave 14 is generated on the sample surface 20. The leaky elastic wave 14 reaches the spherical curved surface 3 a and becomes an ultrasonic wave 5 B, which is detected by the upper electrode 12. In this case, the ultrasonic waves generated from the upper electrode may be reversed. Further, the ultrasonic wave 7A generated at the upper electrode 11 in the central portion is directly reflected on the surface of the sample surface 20 and is again converted into the ultrasonic wave 7B by the upper electrode 11A.
Detected in. The V (z) curve is obtained by the interference of the direct reflected wave 7B and the leaked elastic wave 5B.

Comparing FIGS. 4 (a) and 4 (b), when a lens surface having the same diameter is used, the working distance up to the focal position 42 is obtained in the conventional lens surface having a circular cross section in FIG. 4 (b). Although l ₂ is short, the working distance l ₁ to the focal position 41 is long on the lens surface of this embodiment shown in FIG. Therefore, the number of peaks in the V (z) curve becomes large, and accuracy in anisotropy measurement is improved. V in this embodiment
The (z) curve is shown in FIG.

Further, the cross-sectional views of FIGS. 4 (a) and 4 (b) are shown in FIGS. 6 (a) and 6 (b). FIG. 6 (a) is shown in FIG.
6A is a cross-sectional view taken along the line AA of FIG. 6A, and FIG.
It is a B sectional view. Comparing FIGS. 6A and 6B,
In the conventional technique shown in FIG. 6B, only the X-axis side of the cylindrical surface is used for the V (z) curve, and ultrasonic waves are not focused in the Y-axis direction of the cylindrical surface. Therefore, leaky elastic waves are generated with respect to all ultrasonic waves incident on the entire width of the cylindrical surface in the Y-axis direction, and the average value of these leaky elastic waves is used in the measurement of anisotropy. On the other hand, in the present embodiment shown in FIG. 6A, since the spherical curved surfaces 3a and 3b are spherical curved surfaces and the cylindrical curved surface 4 is cylindrical, the ultrasonic waves are also applied to the lens surface in the Y-axis direction. Are focused. Therefore, the amount of ultrasonic waves input per unit area increases, and the ultrasonic waves incident on the sample surface 20 have stronger power and stronger leaky elastic waves than those of the conventional technique.

Further, horizontal sectional views of FIGS. 6 (a) and 6 (b) are shown in FIGS. 7 (a) and 7 (b). FIG. 7 (a) is shown in FIG. 6 (a).
6B is a cross-sectional view taken along line CC of FIG. 7B, and FIG. Comparing FIGS. 7A and 7B, FIG.
In the conventional technique shown in (b), ultrasonic waves are focused only in the X-axis direction, and in the Y-axis direction, each point in the Z-axis direction is measured by taking an average value of a plurality of focus positions 42, and V (z )
Get the curve. However, in this embodiment shown in FIG. 7A, the ultrasonic waves are focused in both the X-axis direction and the Y-axis direction, and the focus position 41 is applied to the ultrasonic waves 6A and 5B passing through the spherical curved surfaces 3a and 3b. The focus position 43 can be connected to other ultrasonic waves passing through the cylindrical curved surface 4. Therefore, not only the above V (z) curve can be obtained, but also X- at a certain position on the Z axis as shown in FIG.
The focal point 41 is moved in the Y plane to move the focal points 4
A sensor is used to measure 1a, b, c, ..., And based on the measured values at these points, an image processing device connected to the receiver performs image processing to obtain a two-dimensional image. At this time, by selecting an arbitrary position in the Z-axis direction with respect to the focal points 41a, b, ... And focusing the ultrasonic wave on the sample surface, the surface can be observed, and by focusing the ultrasonic wave inside the sample, the inside can be observed. Observations can be made.

According to this embodiment, since the working distance l1 to the focal position 41 can be increased, the number of peaks on the V (z) curve becomes large. Further, since the ultrasonic waves are also focused in the Y-axis direction on the lens surface, stronger leaky elastic waves are generated. Therefore, the accuracy of the anisotropy measurement of the sample surface 20 can be improved and the anisotropy of a minute portion can be measured.

Further, the focus position 41 is moved to move a plurality of points 4
Since a two-dimensional image can be obtained based on the measured values of 1a, b, c, ..., The observation surface can be specified. Furthermore, surface observation and internal observation of the sample can be performed.

A second embodiment of the present invention will be described with reference to FIG. FIG. 9 is a top view of the ultrasonic probe of the present embodiment viewed from the electrode side. Parts common to the first embodiment are designated by common numbers. The ultrasonic probe 60 has an X-axis on the piezoelectric film 9.
In addition to the upper electrodes 10 to 12 arranged in a line in the axial direction,
The upper electrode 1 also extends in the Y-axis direction so as to be orthogonal to these.
6 and 17 are arranged. Thus, the V (z) curve in the Y-axis direction can be simultaneously measured using the upper electrodes 16, 11, and 17. However, in this case, the working distance is the same as the conventional one. The other points are almost the same as those of the ultrasonic probe 50 of the first embodiment.

According to this embodiment, in addition to the effect obtained in the first embodiment, it is possible to measure the V (z) curve in the Y-axis direction. Therefore, the anisotropy in the directions of two orthogonal axes can be measured simultaneously with one probe without moving the probe.

A third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a top view of the ultrasonic probe of this embodiment as viewed from the electrode side. Parts common to those of the first and second embodiments are designated by common numbers. In the ultrasonic probe 70, the lens body 71 includes a cylinder in the X-axis direction and two 1 /
In addition to the shape obtained by cutting the four spherical surfaces, the same shape is cut in the Y-axis direction, that is, the cylinder has a shape orthogonal to the cross shape. Therefore, the opening 75 also has a cross shape as illustrated. Corresponding to this, upper electrodes 72 and 73 are provided on the piezoelectric film 9 in the Y-axis direction. Other points are the first
This is almost the same as the ultrasonic probe 50 of the above embodiment.

According to this embodiment, in addition to the effect obtained in the first embodiment, it is possible to measure the anisotropy of a minute portion in the Y-axis direction with high accuracy. Therefore, the anisotropy in the directions of two orthogonal axes can be simultaneously measured with a single probe with high accuracy and without movement of the probe.

The above is the embodiment of the ultrasonic probe of the present invention. Next, an embodiment of the method of manufacturing the ultrasonic probe will be described with reference to FIGS. A method of manufacturing the ultrasonic probe 50 shown in FIG. 1 is shown in FIG.
This will be described with reference to (c). The procedure for manufacturing the spherical curved surfaces 3a and 3b and the cylindrical curved surface 4 of the ultrasonic probe 50 will be described below. First, a single crystal silicon 31 (for example, 1
(00 wafer) A mask member 30 serving as an etching mask is provided on the surface. For the mask member 30, for example, gold is added to Cr by a “vacuum deposition method” to form a Cr film thickness of 3000 to 500.
Some of them are vapor-deposited with 0Å and gold film thickness of 4000-6000Å.

Next, a resist is applied on the mask member 30, and a long hole having a predetermined size is formed in the resist. An oval opening 32 is formed in the mask member 30 based on the hole formed in the resist (FIG. 11A).

Then, using this as a mask, the single crystal silicon 31 is etched with a mixed solution of hydrofluoric acid, nitric acid, and acetic acid (FIG. 11B). For example, the mixing ratio HF: HN
O ₃ : CH ₃ COOH = 2: 3: 3, a mixture of 50 ° C. and a depth of 2 from a mask having an opening width of 60 μm in about 60 minutes.
A lens surface of about 50 μm is formed. Since the etching performed in this embodiment is isotropic etching, the shape of the opening 15 of the single crystal silicon 31 is similar to the shape of the opening 32 of the mask member 30 (FIG. 11C). The shape of the single crystal silicon 31 after being etched by the R portion of the elliptical corner becomes a quarter spherical surface to form spherical curved surfaces 3a and 3b (FIG. 11 (b)). The incident ultrasonic waves can be focused. Further, the shape of the single crystal silicon 31 after etching by the straight line portion of the ellipse becomes a cylinder to form the cylindrical curved surface 4 (see FIG. 11).
(b)), the working distance to the focus position can be extended.

The material of the acoustic matching layer of the lens body 1 may be SiO _{2 obtained} by thermally oxidizing silicon.

After the spherical curved surfaces 3a and 3b cylindrical curved surfaces 4 are formed on the lens body 1 by the above procedure, the lower electrode 8, the piezoelectric film 9, and the upper electrodes 10 to 12 are provided on the lens body 1.
Then, the ultrasonic probe 50 is manufactured by sequentially attaching.

Further, in the method of manufacturing the ultrasonic probe 60 shown in FIG. 9, in addition to the upper electrodes 10 to 12, the upper electrode 16,
The method of manufacturing the ultrasonic probe 50 is substantially the same as the method of manufacturing the ultrasonic probe 50, except that 17 is attached.

Further, in the method of manufacturing the ultrasonic probe 70 shown in FIG. 10, when the lens surface is formed on the lens body 71 by etching, the cross-shaped opening 33 is formed in the mask member as shown in FIG. Open and use this as a mask 75
Forming a lens surface having. For other points,
The manufacturing method of the ultrasonic probe 50 is substantially the same.

According to this embodiment, since the mask member 30 is provided with the oval opening 32 or the cross-shaped opening 33, a predetermined lens surface of the ultrasonic probes 50, 60, 70 is formed by etching. can do.

[0049]

According to the present invention, since the working distance to the focal position can be increased, the number of peaks on the V (z) curve becomes large. Further, since ultrasonic waves are focused in both the short axis and long axis directions of the lens surface, stronger leaky elastic waves are generated. Therefore, the accuracy of the anisotropy measurement of the sample can be improved and the anisotropy of a minute portion can be measured. Moreover, since the two-dimensional image can be obtained based on the measurement values of a plurality of points by moving the focal position, the observation surface can be specified. Furthermore, surface observation and internal observation of the sample can be performed. Further, if the working distance is the same, a lens surface having a smaller diameter can be used, so that the etching time can be shortened during manufacturing. Therefore, the manufacturing cost can be reduced and the cost can be reduced.

Since the V (z) curve in the minor axis direction of the lens surface can also be measured, the anisotropy in the biaxial directions orthogonal to each other can be measured with one probe at the same time without moving the probe.

Further, according to the present invention, it is possible to improve the accuracy in measuring the anisotropy of the sample in the directions of two orthogonal axes and to measure the anisotropy of a minute portion. Therefore, the anisotropy in the directions of two orthogonal axes can be accurately measured simultaneously with one probe without moving the probe.

[0052]

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an ultrasonic probe according to a first embodiment of the present invention.

FIG. 2 is a bottom view of the ultrasonic probe.

FIG. 3 is a top view of the ultrasonic probe.

FIG. 4 is a diagram comparing the paths of ultrasonic waves in the first embodiment and the prior art.

FIG. 5 shows V obtained by the ultrasonic probe of the first embodiment.
(Z) Curve.

FIG. 6 is a diagram comparing the focusing of ultrasonic waves in the first example and the prior art.

FIG. 7 is a horizontal sectional view comparing the focusing of ultrasonic waves in the first embodiment and the prior art.

FIG. 8 is a diagram showing the movement of the sensor during measurement at a plurality of focal positions.

FIG. 9 is a top view of the ultrasonic probe according to the second embodiment of the present invention.

FIG. 10 is a top view of the ultrasonic probe.

FIG. 11 is a diagram showing a method for manufacturing an ultrasonic probe.

FIG. 12 is a diagram showing a relationship in shape between the opening of the mask member and the opening of the lens surface.

FIG. 13 is an overall configuration diagram of a conventional ultrasonic probe.

FIG. 14 is a bottom view of a conventional ultrasonic probe.

FIG. 15 is a system configuration diagram of a conventional ultrasonic microscope.

FIG. 16: V obtained by a conventional ultrasonic probe
(Z) Curve.

[Explanation of symbols]

1 Lens Main Body 2 Lens Surface 3a Spherical Curved Surface 3b Spherical Curved Surface 4 Cylindrical Curved Surface 5A, 5B Ultrasonic Wave 6A, 6B Ultrasonic Wave 7A, 7B Ultrasonic Wave 10 Upper Electrode 11 Upper Electrode 12 Upper Electrode 14 Leaky Elastic Wave 15 Opening 16 Upper electrode 17 Upper electrode 20 Sample surface 30 Mask member 31 Single crystal silicon 32 Aperture 33 Aperture 41 Focus position 41a, b, c, ... Focus position 43 Focus position 50 Ultrasonic probe 60 Ultrasonic probe 70 Ultra Sound wave probe 71 Lens body 72 Upper electrode 73 Upper electrode 75 Opening l ₁ Working distance

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Morio Tamura, Inoue, Tsuchiura-shi, Ibaraki, 650, Kuchidachi-machi, Hitachi Construction Machinery Co., Ltd. (72) Inventor, Kiyoshi Ishikawa 2-6-2 Otemachi, Chiyoda-ku, Tokyo Nitto Construction Machinery Co., Ltd.

Claims (7)

[Claims] 1. An ultrasonic lens, comprising an acoustic lens having a piezoelectric body arranged at one end and a lens surface formed at the other end, wherein a voltage is applied to the piezoelectric body by electrode means located above and below the piezoelectric body. In the ultrasonic probe for generating the laser beam and focusing the ultrasonic wave on the lens surface to irradiate the sample to obtain information of the sample, the lens surface includes at least one pair of facing spherical curved surfaces and the facing surface. And one cylindrical curved surface having a flat cross section in the major axis direction, which is located between the spherical curved surfaces, and the ultrasonic wave reaches the positions of the curved surface and the cylindrical curved surface facing each other. The ultrasonic probe is characterized in that. 2. The ultrasonic probe according to claim 1, wherein:
The electrode means is composed of an upper electrode and a lower electrode, and the upper electrode is provided in a row in the major axis direction and the minor axis direction of the lens surface, and the electrode row in the major axis direction and the minor axis direction are provided in the major axis direction. An ultrasonic probe, wherein the electrode array is arranged so as to be orthogonal to the piezoelectric body. 3. An ultrasonic lens, comprising an acoustic lens having a piezoelectric body arranged at one end and a lens surface formed at the other end, wherein a voltage is applied to the piezoelectric body by electrode means located above and below the piezoelectric body. In the ultrasonic probe for focusing the ultrasonic wave on the lens surface and irradiating the sample to obtain information on the sample, the lens surface includes two cylindrical curved surfaces orthogonal to each other, and the cylindrical surface. Two sets of spherical curved surfaces that are provided at both ends of the curved surface and that oppose each other are provided. The electrode means is composed of an upper electrode and a lower electrode, and the upper electrode is the same as the two cylindrical curved surfaces. An ultrasonic probe, wherein the ultrasonic probes are arranged in a line in each direction so as to be orthogonal to each other on the piezoelectric body. 4. The ultrasonic probe according to claim 1, wherein the acoustic lens is silicon. 5. The ultrasonic probe according to claim 1, wherein the acoustic matching layer of the acoustic lens is made of SiO ₂ obtained by thermally oxidizing silicon. Tentacles. 6. An acoustic lens having a piezoelectric body disposed at one end and a lens surface formed at the other end, wherein a voltage is applied to the piezoelectric body to generate ultrasonic waves, and the ultrasonic waves are transmitted to the lens surface. In the method for manufacturing an ultrasonic probe, which is focused on, irradiates a sample, and obtains information on the sample, by etching using an elliptical etching mask,
The acoustic lens is characterized in that a lens surface having a pair of opposed spherical curved surfaces and a cylindrical curved surface located between the opposed spherical curved surfaces and having a flat longitudinal cross section is formed. Manufacturing method of ultrasonic probe. 7. An acoustic lens having a piezoelectric body disposed at one end and a lens surface formed at the other end, wherein a voltage is applied to the piezoelectric body to generate ultrasonic waves, and the ultrasonic waves are transmitted to the lens surface. In the method of manufacturing an ultrasonic probe, which focuses light on a sample and irradiates the sample to obtain information on the sample, two cylinders orthogonal to the acoustic lens are formed by etching using etching masks having two elliptical shapes that are orthogonal to each other. A method of manufacturing an ultrasonic probe, comprising forming a lens surface having a curved surface and two pairs of spherical curved surfaces facing each other provided at four positions on both ends of the cylindrical curved surface.