JPH0510933A - Ultrasonic sensor and ultrasonic spectrum microscope using the same - Google Patents

Abstract

PURPOSE:To obtain an ultrasonic spectrum microscope capable of executing ultrasonic scanning of a body to be inspected, without being accompanied by mechanical scanning. CONSTITUTION:An ultrasonic sensor 1 is a transmission-reception independence type sensor constructed of an array type cylindrical transducer 12 and a planar transducer 14. An input signal to be impressed on each piezoelectric element 24 of a piezoelectric element group 22 of the array type cylindrical transducer 12 from a pulser 38 is given a delay time by an input signal processing circuit 34a. Thereby a time lag is made to occur in the time of generation of an ultrasonic wave by each piezoelectric element 24 of the piezoelectric element group 22. By setting this time lag appropriately, the ultrasonic wave propagated from the array type cylindrical transducer 12 is point-focused at a desired one point on a scanning line 20b on the surface 20a of a body to be inspected. A reflected wave from this focusing point is received by the planar transducer 14, converted into an electric signal and then subjected to a spectrum analysis in FFT 54.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic sensor which transmits a high frequency ultrasonic wave to a subject and outputs a reflected wave output thereof. The present invention also relates to an ultrasonic spectrum microscope for measuring the physical characteristics of a subject, the film thickness, the adhesion, etc. by evaluating the spectrum of the reflected wave output of this ultrasonic sensor.

[0002]

2. Description of the Related Art An ultrasonic spectrum microscope disclosed in, for example, Japanese Unexamined Patent Publication No. 251751/1990 includes a transmission / reception independent ultrasonic sensor including a pair of ultrasonic transducers of a flat transducer and a spherical concave transducer. .

The ultrasonic waves transmitted from the spherical transducer are focused and incident on a minute point of the subject due to the focusing action of the spherical surface. This incident wave is dispersed and reflected while being influenced by the elastic characteristics and structure of the subject, received by the flat transducer, and converted into an electric signal. Such a sensor provides high spatial resolution due to the focusing properties of the spherical transducer. Further, due to phase interference on the piezoelectric surface of the flat transducer, a reflected wave of only a component having a specific incident angle (that is, an angle formed by the normal line of the plane and the normal line of the subject surface) is converted into an electric signal and output. . By evaluating the intensity spectrum and phase spectrum of the reflected wave based on this output signal, the elastic constant, film thickness, anisotropy, etc. of the subject can be quantitatively measured.

[0004]

However, since the incident wave from the spherical transducer is focused on a minute point, it has a high spatial resolution, but can measure only one point at a time. Therefore, in order to perform multipoint measurement, the sensor itself must be mechanically scanned along the surface of the subject, and it is difficult to speed up the measurement.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to perform measurement at many measurement points at high speed, although mechanical scanning is unnecessary. Another object of the present invention is to provide an ultrasonic sensor and a spectrum microscope using the same.

[0006]

In order to achieve the above object, the ultrasonic sensor of the present invention is provided with first and second wave transmitting / receiving means, one of which is used as a wave transmitting side and a high frequency signal is transmitted. When applied, it transmits high-frequency ultrasonic waves to the surface of the subject, and the other side is used as the receiving side to receive reflected ultrasonic waves from the subject and generate an electric signal corresponding to the intensity of the reflected ultrasonic waves. A first transmission / reception independent type ultrasonic sensor for outputting; a first transmission / reception means, wherein a plurality of ultrasonic piezoelectric elements are arrayed at equal intervals so that each piezoelectric element independently produces a piezoelectric effect. While having a piezoelectric element group that is arranged,
In order to make a high frequency ultrasonic wave which this piezoelectric element group emits into a converging wave, it has a cylindrical wave-transmission-and-reception surface which makes the arrangement direction of the above-mentioned array-like arrangement a longitudinal direction; Has a planar ultrasonic piezoelectric element and a planar transmitting / receiving surface.

According to the embodiment of the present invention, the first and second wave transmitting / receiving means are integrally formed.

Each piezoelectric element of the first wave transmitting / receiving means has a piezoelectric body sandwiched between a pair of electrodes, and the surface of the piezoelectric body may be formed into a cylindrical surface or a flat surface. Good.

At least one of the member forming one of the pair of electrodes of each piezoelectric element of the first wave transmitting / receiving means and the member forming the piezoelectric body is a plurality of piezoelectric elements. May be integrally formed.

The piezoelectric element group of the first wave transmitting / receiving means may include a delay member having the cylindrical surface wave transmitting / receiving surface.

In the piezoelectric element of the second wave transmitting / receiving means, a piezoelectric body having a flat piezoelectric surface may be sandwiched between a pair of flat electrodes, and further, the delay having the flat wave transmitting / receiving surface is formed. You may have a material.

The length L of the piezoelectric element of the second transmitting / receiving means in an arbitrary direction is expressed by the following equation: L ≧ (1 / sin β)  (V / ω) (where V is in the ultrasonic wave propagating medium) Sound velocity, ω is the time frequency of the ultrasonic wave transmitted by the ultrasonic sensor, or the frequency of the minimum intensity part in the spectrum intensity distribution of the reflected ultrasonic wave received by the ultrasonic sensor, β is the incident angle selection ability of the ultrasonic sensor Is a value that represents, and the angle formed by the normal of the plane wave transmitting / receiving surface of the second wave transmitting / receiving means and the normal of the subject surface is θ, It is preferable to satisfy a value indicating that the incident angle component of the sound wave is only in the range of θ ± β.

When the first transmitting / receiving means is used on the transmitting side, ultrasonic waves transmitted from arbitrary integer N adjacent piezoelectric elements forming at least a part of the piezoelectric element group become the focal point. It further comprises input signal processing means for applying a predetermined time difference to the high-frequency signals to be applied to the respective piezoelectric elements of the first wave transmitting / receiving means so as to be focused at one point and apply the signals to the respective piezoelectric elements. preferable.

When the first wave transmitting / receiving means is used on the wave receiving side, from an electric signal output from an arbitrary integer N adjacent piezoelectric elements forming at least a part of the piezoelectric element group,
The electric signal output from each piezoelectric element of the first wave transmitting / receiving means is given a predetermined time difference so that an electric signal corresponding to the intensity of the reflected wave reflected from one point serving as the focal point is formed. It is preferable to further include output signal processing means for combining.

In the ultrasonic spectrum microscope according to the present invention as defined in claim 12, each of the measurement is performed on an object in which a virtual linear scanning line formed by arranging a plurality of measurement points on a straight line extends on the surface. A high-frequency ultrasonic wave is focused on a point to linearly scan the subject along a linear scanning line, and based on the electrical signal obtained from each measurement point, an intensity spectrum showing its intensity as a function of frequency is formed. An ultrasonic spectrum microscope for: a table on which an object is to be placed; a high frequency ultrasonic wave to be transmitted from the first transmitting / receiving means, to be incident on a linear scanning line, and for this incident wave The ultrasonic sensor according to any one of claims 1 to 9, which is arranged so that a reflected wave from the subject is received by the second transmitting / receiving means; and an input signal of the ultrasonic sensor. A high-frequency oscillating means for oscillating a high-frequency signal as; a high-frequency ultrasonic wave to be transmitted from at least a part of the piezoelectric elements of the first transmitting / receiving means of the ultrasonic sensor is linearly focused on each measurement point. An input signal for applying a predetermined time difference to the high-frequency signal of the high-frequency oscillating means and applying it to at least a part of the piezoelectric elements of the first transmitting / receiving means so that the subject is linearly scanned along the scanning line. It is characterized by comprising processing means; and intensity spectrum forming means for forming an intensity spectrum thereof based on the electric signal output from the piezoelectric element of the second wave transmitting / receiving means of the ultrasonic sensor.

According to the ultrasonic spectrum microscope of the present invention as defined in claim 13, a virtual linear scanning line formed by arranging a plurality of measurement points on a straight line is formed on the surface of a subject having a virtual scanning line. A high-frequency ultrasonic wave is transmitted, and based on the reflected wave from the linear scanning line, the subject is linearly scanned by forming the reflected wave output at each measurement point, and the intensity of the reflected wave at each measurement point is measured. An ultrasonic spectrum microscope for forming an intensity spectrum as a function of frequency; a table on which an object is to be placed; a high frequency ultrasonic wave to be transmitted from a second transmitting and receiving means on a linear scanning line. The ultrasonic sound according to any one of claims 1 to 9, wherein the ultrasonic wave is arranged so as to be incident and the reflected wave from the subject with respect to the incident wave is received by the first wave transmitting / receiving means. A sensor; a high-frequency oscillating means for oscillating a high-frequency signal and applying the high-frequency signal to a piezoelectric element of a second wave transmitting / receiving means of the ultrasonic sensor; at least a part of the first wave transmitting / receiving means of the ultrasonic sensor Reflection of the piezoelectric element of at least a part of the first transmitting / receiving means so as to form an electric signal corresponding to the intensity of the reflected wave reflected from each measurement point based on the electric signal output from the piezoelectric element. Output signal processing means for adding a predetermined time difference to the wave output to synthesize the wave output; and intensity spectrum forming means for forming an intensity spectrum of the reflected wave output based on the synthesized reflected wave output. Ultrasonic spectrum microscope.

These ultrasonic spectrum microscopes form a phase spectrum, which forms a phase spectrum whose phase is shown as a function of frequency, based on the electric signal output from the piezoelectric element of the second transmitting / receiving means of the ultrasonic sensor. It is preferable to further comprise means.

The high frequency signal oscillated by the high frequency oscillating means may be a wide band pulse signal so that the high frequency ultrasonic wave emitted by the ultrasonic sensor becomes a wide band pulse wave, or the high frequency ultrasonic wave emitted by the ultrasonic sensor is A burst signal that is oscillated while sweeping the frequency so that it becomes a burst wave may be used.

When the surface direction of the object is the xy direction and the extending direction of the linear scanning line on the surface of the object is the y direction,
A moving means is further provided for mechanically moving at least one of the ultrasonic sensor and the table relative to the other so as to move the linear scanning line in the x direction along the surface of the subject. May be.

In order to make variable the incident angle or the receiving angle defined by the angle formed by the normal line direction of the plane wave transmitting / receiving surface of the second wave transmitting / receiving device and the normal line direction of the object surface, An angle control means for tilting the wave transmitting / receiving means 2 with respect to the normal direction of the surface of the subject may be further provided.

The angle control means may integrally tilt the first and second wave transmitting / receiving means around the tilting central axis which is parallel to the extending direction of the linear scanning line.

The angle control means for tilting the first and second wave transmitting / receiving means integrally so that the focal point of the ultrasonic wave transmitted by the first wave transmitting / receiving means is located on the tilt center axis line. A focus position adjusting means for integrally moving the first and second wave transmitting / receiving means in at least one direction may be provided.

The focus position adjusting means integrally moves the first and second wave transmitting / receiving means in a direction orthogonal to the moving direction and the normal line direction of the surface of the object when the focus is adjusted. A tilting means for tilting may be provided.

[0024]

According to the above ultrasonic sensor, assuming that each piezoelectric element of the piezoelectric element group of the first transmitting / receiving means simultaneously transmits ultrasonic waves, the ultrasonic waves are line-focused by the lens action of the cylindrical surface. . However, by giving an appropriate time difference to the time when each piezoelectric element transmits the ultrasonic wave, the ultrasonic wave can be point-focused at a certain measurement point at a certain time, and this point-focused position is changed. be able to. Therefore, the subject can be scanned without mechanically two-dimensionally scanning the ultrasonic sensor itself.

Further, according to the ultrasonic spectrum microscope using this ultrasonic sensor, by obtaining the reflected wave intensity from each measurement point while scanning the subject as described above,
A spectrum intensity distribution is formed whose intensity is shown as a function of frequency.

[0026]

FIG. 1 schematically shows an ultrasonic spectrum microscope according to an embodiment of the present invention. An ultrasonic spectrum microscope (hereinafter, abbreviated as UMSM) includes a table 110 that can be driven in the X direction. The subject 20 is placed on the table 110. Here, with respect to the driving direction X of the table 110, an XYZ coordinate system in which the normal direction is the Z direction and the direction orthogonal to these X and Z directions is the Y direction is defined. Further, an xyz coordinate system in which the plane formed by the subject surface 20a is the xy plane and the normal direction is the z direction is defined. However, in FIG. 1, it is assumed that the XYZ coordinate system and the xyz coordinate system coincide with each other.

A virtual linear scanning line 20b extending in the y direction is defined on the surface 20a of the subject 20.
A linear scan of the subject 20 is performed by the UMSM along the linear scan line 20b. This linear scanning is executed by electrical signal processing without mechanical scanning of the ultrasonic sensor 1 of the UMSM as described later. U
The ultrasonic sensor 1 of the present invention used in the MSM is a transmission / reception independent sensor including a pair of a focusing transducer 12 and a plane transducer 14.

The focusing transducer 12 has a cylindrical ultrasonic wave transmitting / receiving surface 16, and the plane transducer 14 has a flat ultrasonic wave transmitting / receiving surface 18.

These transducers 12 and 14 are connected to one of the linear scanning lines 20 on the surface 20a of the subject.
It is arranged so that the reflected wave with respect to the ultrasonic wave transmitted to b is received by the other.

Further, the plane 1 of the plane transducer 14
The normal line 8 and the normal line to the surface 20a of the subject form an acute angle θ. This acute angle θ is the incident angle when the plane transducer 14 is used on the transmitting side, and the receiving angle (when the plane transducer 14 is used on the receiving side ( Detection angle).

Each of these transducers 12 and 14 serves both as the ultrasonic wave transmitting side and the ultrasonic wave receiving side, but FIG. 1 shows an example in which the former is the transmitting side and the latter is the receiving side.

Water (not shown) as an ultrasonic wave propagation medium is interposed between the ultrasonic wave transmitting / receiving surfaces 16 and 18 of the transducers 12 and 14 and the subject 20.

The focusing transducer 12 is an array type transducer having a piezoelectric element group 22, particularly as shown in FIG. The piezoelectric element group 22 includes, for example, 100 strip-shaped piezoelectric elements 24, which are parallel to each other in the longitudinal direction of the cylindrical surface 16 so that the piezoelectric elements 24 independently generate each other.
Are arranged in an array along the longitudinal direction, that is, the Y direction. A plurality of piezoelectric elements 24 forming the piezoelectric element group 22
Is a plate-shaped piezoelectric body 30 sandwiched between a plurality of strip-shaped upper electrodes 26 and a plate-shaped lower electrode 28. The upper electrode 26 is formed by, for example, plating, and the lower electrode 28 is formed by, for example, vapor deposition or plating.

Each element 24 of the piezoelectric element group 22 has a longitudinal length of, for example, 50 mm and its width, that is, the upper electrode 26.
Has a width of, for example, 80 μm. Two adjacent elements 2
4, the center distance between the upper electrodes 26, that is, the center distance Δd between the upper electrodes 26.
Are equally spaced, for example 100 μm.

A delay material 32a is attached to the lower surface of the lower electrode 28, and the cylindrical surface 16 is formed at the lower end of the delay material 32a. The focusing radius of this cylindrical surface 16 is, for example, 1
It is 0 mm.

On the other hand, the flat transducer 14 has, for example, a single flat plate-shaped piezoelectric element 40.
In the case of 0, a flat plate-shaped piezoelectric body 46 is sandwiched between a pair of upper and lower flat plate-shaped electrodes 42 and 44. A delay material 32b is attached to the lower surface of the lower electrode 44, and the flat surface 18 is formed at the lower end of the delay material 32b. In the illustrated example, the delay member 32b of the flat transducer 14 and the delay member 32a of the focusing transducer 12 are integrally formed via the intermediate delay member 32c.

Electrode 2 of each transducer 12, 14
6, 28, 42 and 44 are, for example, 5000 Å thick gold foils, and the piezoelectric bodies 30 and 40 are, for example, 30 μm.
Thick P (VDF-TrFE) organic film, delay material 32a, 3
2b and 32c are, for example, fused quartz.

The shapes of the transducers 12 and 14 are not limited to those shown in the figure. For example, delay material 3
2a, 32b and 32c do not necessarily have to be used. If the delay member 32a is not used here, the cylindrical surface 16 of the focusing transducer 12 has the electrodes 26, 28 and the piezoelectric body 30.
Can be formed by bending into a cylindrical shape.

Further, the electrode 2 of the focusing transducer 12
The vertical relationship between 6 and the electrode 28 may be reversed. That is,
A strip electrode 26 may be provided on the side of the cylindrical surface 16. In this case, a holding member (not shown) or 32a, 32b of each of the transducers 12 and 14 may be formed of a conductive member so that they also serve as electrodes.
Further, it is desirable that the portions of the transducers 12 and 14 that come into contact with water be covered with a waterproof film (not shown) made of a non-conductive organic film having a thickness of 1 μm, for example.

Each piezoelectric element 2 of the focusing transducer 12
An output terminal of the input signal processing circuit 34a is connected to 4. This input signal processing circuit 34a is provided for each piezoelectric element 24.
And a control unit 36b that controls a time difference due to the delay elements 36a. Also,
The pulsar 3 is connected to the input terminal of the input signal processing circuit 34a.
8 is connected.

The pulsar 38 generates, for example, a wide band pulse signal as a drive voltage for each band-shaped piezoelectric element 24. This pulse signal is given a time difference in the input signal processing circuit 34a, and then, the pair of electrodes 26, 2 of each strip-shaped piezoelectric element 24.
It is applied between 8 times. As a result, a plane wave is emitted from each band-shaped piezoelectric element 24 to the delay member 32a. This plane wave is made a focused wave by the lens action of the cylindrical surface 16 at the lower end of the delay member 32a and is transmitted from the cylindrical surface 16. This ultrasonic wave is incident on the surface 20a of the subject through water and is focused on the line 20b.

The plane transducer 14 includes an amplifier 5
0, oscilloscope 52, FFT analyzer 54, CR
T56 is connected in order.

Subject 2 from Focusing Transducer 12
The incident wave to 0 is reflected by the subject 20 and received by the wave receiving surface 18 of the flat transducer 14 via water, and converted into an electric signal. This electric signal is amplified by the amplifier 50 and given to the oscilloscope 52. Oscilloscope 5
2 forms a time waveform of the supplied electric signal and supplies it to the FFT analyzer 54. The FFT analyzer 54 forms a spectrum intensity distribution showing the intensity of the reflected wave as a function of frequency by applying a fast Fourier transform to the given time waveform. Further, a spectrum phase distribution in which the phase of the reflected wave is shown as a function of frequency may be formed.
The spectrum intensity distribution and spectrum phase distribution thus formed are displayed on the CRT 56.

Next, the linear scanning by the above UMSM will be described.

As shown in FIG. 3, consider N piezoelectric elements 24 arranged in series in the piezoelectric element group 22 of the focusing transducer 12. For simplification of explanation, it is assumed that the piezoelectric element group 22 shown in FIG. 3 does not have the delay member 32a and that the piezoelectric element group 22 itself is bent so as to form the cylindrical surface 16.

In FIG. 3, the piezoelectric element 24 having a center line at a position of a distance n, which will be described later, is indicated by a symbol E _n . Here, the distance n is a distance along the array arrangement direction between the position and the median of each element E _n , where 0 is the position closest to the focus on the surface _where the piezoelectric elements E _n are formed. . For simplification of description, the distance n between the elements E ₀ having the center line at the position n = 0 on the right side of the figure is sequentially 1, 2, 3, ... Similarly, the 0th element E _0. The distances n of the elements on the left side of the figure are sequentially -1, -2, -3, ... The measurement point closest to each element E _n is indicated by P _n .

When the N elements E simultaneously emit ultrasonic waves, the ultrasonic wave transmitting surface 16 of the N elements E is a cylindrical surface, so the ultrasonic waves of the N elements E are transmitted to the scanning line 20b. Focus. Here, at a certain time, the ultrasonic waves independently emitted from the N elements E of the focusing transducer 12 are focused on only one measurement point on the line 20b, and the reflected wave from this one measurement point is focused. In order to be received by the planar transducer 14, a time difference may be added to the pulse signals to be applied to each of the N elements E _n .

For example, consider a case where the ultrasonic waves from the N elements E _n are focused on the measurement point P ₀ on the linear scanning line 20b. In this case, of the N elements E _n , the measurement point P
One element E ₀ immediately above ₀ does not need to give a time difference. Therefore, it suffices to consider the order in which the time difference should be given with reference to the element E ₀ .

When the ultrasonic wave propagation distance from the _0th element E ₀ to the measurement point P ₀ is L ₀ , the element E _n to the measurement point P ₀
The ultrasonic propagation distance L _{n up to} is L _n = {L ₀ ² + n ² } ^1/2 −L ₀ from the right-angled triangle theorem.

The time t _Ln required for the ultrasonic wave emitted from each element E _n to propagate through this ultrasonic wave propagation distance L _n is t
Because it is _Ln = L _n / V, it is given by ^{_{t Ln = [{L 0 2}} + n 2} 1/2 -L 0] / V. Here, V is the speed of sound in the ultrasonic wave propagating medium, and is the speed of sound V _w in water in this embodiment. Therefore, the time difference τ _{n to} be given to each of the N elements E _n is given by the following equation.

[0051]

[Equation 1]

On the other hand, when the focusing transducer 12 has the delay member 32a as shown in FIG. 1, it is necessary to consider the delay of the ultrasonic wave by the delay member 32a.
In this case, the time difference τ _{n to} be given to each of the N elements E _n is given by the following equation.

[0053]

[Equation 2]

However, L _n ′ and D ′ satisfy the following equation.

[0055]

[Equation 3]

Here, V _p is the speed of sound in the delay material 32a, D is the thickness of the delay material, and L _n ′ and D ′ are the paths in which ultrasonic waves can propagate from the element E _n to the measurement point P _n . They are the propagation distance in the ultrasonic propagation medium and the propagation distance in the delay material 32a that have the shortest propagation time.

This delay time τ _n is used as the input signal processing circuit 34.
By adding to the pulse signal by a, the ultrasonic wave can be point-focused to the measurement point P ⁰ without mechanically moving the ultrasonic sensor 1 itself, and the reflected wave at the measurement point P ₀ can be received at an angle of reception. Can be received at Δθ. Further, the point focusing position is moved to each measurement point P _n by setting the element closest to each other measurement point P _n as the 0th element and giving a time difference according to the above formula [i] or [ii]. You can As a result, the spectrum intensity distribution and the spectrum phase distribution at each measurement point can be measured by linearly scanning the subject 20 without requiring the mechanical scanning mechanism of the ultrasonic sensor 1.

Incidentally, instead of the input signal processing circuit 34a, it is also possible to adopt a configuration in which the time difference given by the above formula [i] or [ii] is executed by an appropriate arithmetic unit.

A measurement example using the UMSM of the first embodiment will be described. In UMSM, the thickness of the film formed on the subject is determined by the frequency of the minimum intensity portion on the spectrum intensity distribution or the frequency f of the phase change portion on the spectrum phase distribution, and the elastic properties of the subject and the ultrasonic propagation medium. It can be obtained as a ratio with a constant C determined by

In this measurement example, the object 20 is 42N.
The thickness of the gold film was determined by using a gold thin film formed on the surface of the i-Fe alloy substrate.

The ultrasonic sensor 1 is arranged so that the ultrasonic wave detection angle of the flat transducer 14 is 30 °. The time difference was according to the above formula [ii].

The spectrum intensity distribution and spectrum phase distribution obtained by this measurement example are shown in FIG.
(A) and FIG. 4 (B) are shown.

As is clear from these figures, in the spectrum intensity distribution, an intensity minimum appears at a frequency of 10 MHz,
Even in the spectrum phase distribution, a phase change appears at a frequency of 10 MHz. This indicates that when the ultrasonic wave detection angle (or incident angle) is 30 °, surface acoustic waves are excited on the surface 20a of the object to be inspected by ultrasonic waves having a frequency of 10 MHz. Assuming that the constant C in this measurement example is 300 from known data, the gold film thickness d of the subject 20 is
_g was _calculated as d _g = C / f = 300/10 = 30 [μm].

FIG. 5 schematically shows a UMSM of the second embodiment of the present invention. This UMSM transmission / reception independent ultrasonic sensor 1
The structure of the transducers 12 and 14 is similar to that of the sensor 1 shown in FIG. However, the array-type focusing transducer 12 is used on the receiving side and the plane transducer 14 is used on the transmitting side. According to such a sensor 1, when a wideband pulse wave is used, the array type focusing transducer 12 can be transmitted from an arbitrary measuring point on the subject 20 by only transmitting the ultrasonic wave once from the planar transducer 14. The reflected wave signal of can be output.

In FIG. 5, the planar transducer 14
A pulsar 38 is connected to the. The broadband pulse signal generated by the pulsar 38 is applied between the pair of upper and lower electrodes 42, 44 of the piezoelectric element 40. As a result, an ultrasonic wave is transmitted from the flat transducer 14, is incident on the surface of the subject 20 through water at an incident angle Δθ, and is reflected here.

An amplifier 58 and a delay element 36a of the output signal processing circuit 34b are respectively provided in the respective band-shaped piezoelectric elements 24 of the array type focusing transducer 12 which receives the reflected wave.
Are connected. Further, on the output side of the output signal processing circuit 34b, an oscilloscope 52, an FFT analyzer 54,
The CRT 56 is sequentially connected.

Each piezoelectric element 24 of the array type focusing transducer 12 converts the received reflected wave into an electric signal and outputs the electric signal to the corresponding amplifier 58. The amplifier 58 amplifies the electric signal and delays the delay element 36 of the output signal processing circuit 34b.
give to a. The output signal processing circuit 34b includes the delay control unit 3
By the control of 6b, each time waveform is given the time difference τ _n given by the above equation [ii], and then each time waveform is synthesized, and this synthesized waveform is output.

The combined waveform output from the output signal processing circuit 34b corresponds to the reflected wave output from the measurement point immediately below the 0th element 24. Therefore, the output signal processing circuit 34b
Is the measurement point P depending on the position of the element 24 which should be E _{(n = 0)}
It is possible to output a reflected wave output for an incident wave having an incident angle θ at _n . Based on the output of this reflected wave, a spectrum intensity distribution and a spectrum phase distribution are formed through the oscilloscope 52 and the FFT analyzer 54 as in the example of FIG. 1, and displayed on the CRT 56.

The structure of the output side of the array type focusing transducer 12 in the second embodiment may be replaced with the structure shown in FIG. In this example, the planar transducer 14
The switch 51 sequentially switches the output waveform of each piezoelectric element 24 to the amplifier 53 by the trigger signal from the pulsar 38 that applies the broadband pulse signal to the. This amplifier 53
From the output waveform of each piezoelectric element 24 amplified in step 1, a waveform corresponding to the reflection waveform of each measurement point is formed by the digital oscilloscope 55 and stored in the waveform storage 57.

This stored waveform is calculated by the computing unit 59 so that the reflected wave from the intended measurement point can be obtained.
Given _{n, they} are synthesized. Based on this composite waveform,
The calculator 59 forms a spectrum intensity distribution and a spectrum phase distribution, which are displayed on the CRT 56. The configuration of the output side of the array type focusing transducer 12 as shown in FIG. 6 can be simplified as compared with the configuration of FIG.

Further, instead of sampling the waveform from each element 24 by switching the switch 51 while repeatedly oscillating an electric signal, a waveform sampling device such as a digital oscilloscope is arranged in the same number as the number of the elements 24 and each element is arranged. The waveform from 24 may be collected at one time.

An example of measurement using the UMSM according to the second embodiment will be described. In this measurement example, the subject 2
As 0, a substrate in which a gold thin film was formed on the surface of a 42Ni—Fe alloy substrate was used, and the phase velocity of the Rayleigh wave excited on the surface 20a was measured.

First, while changing the incident angle of the ultrasonic wave transmitted from the flat transducer 14 with respect to the surface 20a of the object to be examined, a reflected wave composite waveform for one measurement point on the linear scanning line 20b for the different incident angle is formed. Then, the spectrum intensity distribution and the spectrum phase distribution were formed. Here, the time difference complies with the above equation [ii]. Further, a θ stage 82 (see FIG. 8) described later can be used as a means for changing the incident angle.

Next, when the change in the phase of the frequency 20 MHz component in the measured spectrum phase distribution was plotted against the incident angle, the characteristics shown in FIG. 7 were obtained.

As is apparent from FIG. 7, it is understood that the phase of the reflected wave from the minute measurement point is rotated at the incident angle of 23 degrees. This indicates that the Rayleigh wave, which is a surface acoustic wave, was excited at an incident angle of 23 degrees. As a result, the phase velocity V _phase of the subject 20 is V _phase = 1500 / sin (23) = 3846 [m according to Snell's law, assuming that the speed of sound in the ultrasonic propagation medium (water in this example) is 1500 m / sec. / Sec] was required. The above is an example of measuring the phase velocities of Rayleigh waves at one measurement point on the linear scanning line 20b, but the phase velocities at other measurement points can be measured without the need for another ultrasonic wave transmission. Is. That is, in the above formula [ii], the reflected wave composite waveform of another measurement point is formed by moving the waveform with n = 0 by calculation, and the phase velocity of the other measurement point can be measured based on it.

In the planar transducer 14 in each of the above-mentioned embodiments, the width L in the longitudinal direction is expressed by the following formula: L ≧ (1 / sin β) · (V / ω) (2-1) (where V is The sound velocity in the ultrasonic wave propagation medium, in the above embodiments, the sound velocity V _{W in} water, ω is the time frequency of the ultrasonic wave transmitted by the ultrasonic sensor, or the minimum value of the frequency of the frequency distribution, β Is preferably a value representing the incident angle selection ability of the ultrasonic sensor).

This will be described using the ultrasonic sensor 1 (FIG. 1) in the first embodiment. In FIG. 8, the incident angle θ of the flat transducer 14 defined by the surface 20a of the subject is the angle between the normal N ₁ of the flat transducer 14 and the normal N _{2 of the} surface 20a of the subject. As shown in FIG. 5, the planar transducer 14
It is assumed that the ultrasonic wave to be received by the antenna has an incident angle component deviated from the incident angle θ by an angle α. It is known that the reflected wave output of the ultrasonic sensor 1 in this case is as shown in FIGS. 9 and 10.

When α = 0, the plane transducer 1
This corresponds to the case where an ultrasonic wave is vertically incident on the beam No. 4. When the width L is large, the output of the ultrasonic sensor 1 sharply decreases even if α is small, and generally the output becomes minimum at the angle α = β.
Here, it is clear from FIG. 11 that β satisfies the following equation. β = Sin ⁻¹ (λ / L) (2-2) where λ is the wavelength of the ultrasonic wave, and λ = V / ω, that is, λ = V _W / ω in each of the above embodiments.

The incident angle component of the ultrasonic wave deviated from the incident angle θ by the angle β obtained by the equation (2-2) becomes minimum due to phase interference over the entire width L of the flat transducer 14. That is, β is a parameter indicating that the ultrasonic sensor 1 can output only the incident angle component of the ultrasonic wave in the range of θ ± β with a large intensity. If β is defined as the incident angle selecting ability, the width L of the flat transducer 14 having the incident angle selecting ability β is given by the equation (2-1) by modifying the equation (2-2). The output characteristics of the ultrasonic sensor and the equation (2-1) described here are applicable to the delay members 32a and 32 of one or both of the pair of transducers 12 and 14 even if the flat transducer 14 is used on the transmitting side.
It has been confirmed that it holds regardless of the presence or absence of b.

FIG. 12 shows a UMS according to the third embodiment of the present invention.
1 shows the overall structure of M. This UMSM is provided with means for adjusting the focus of the ultrasonic sensor 1.

In FIG. 12, the same components as those in the first and second embodiments are designated by the same reference numerals.
However, the input signal processing circuit 34a and the output signal processing circuit 34b in this UMSM are the array type cylindrical transducer 12 and the planar transducer 1 of the ultrasonic sensor 1.
It is selectively provided depending on which of 4 and 4 is used on the transmitting side.

In FIG. 12, the UMSM comprises a Z stage 68 and a sensor drive mechanism 80 as focus adjusting means for the ultrasonic sensor 1. When such a focus adjusting means is provided, it is preferable that the array type transducer 12 and the cylindrical planar transducer 14 of the ultrasonic sensor 1 are integrally formed. This is because high frequency ultrasonic waves have a short wavelength and fine adjustment is required for the focus adjustment. Therefore, when adjusting the focus, the transducers 12, 1 are used.
This is because it is desirable to be able to drive 4 integrally.

Further, such a focus adjusting means need not be provided especially when the ultrasonic sensor 1 is used while being fixed to the manufacturing line of the subject 20 such as a circuit board.

The vertical frame 6 is provided on the base 60 of the UMSM.
A frame body 62 composed of four and a horizontal frame 66 is provided upright. The lateral frame 66 has a sensor drive mechanism 8
A Z stage 68 holding 0 is slidably attached. The Z stage 68 is provided on the ultrasonic sensor 1 and the subject 20 in order to adjust the depth of focus of the ultrasonic sensor 1.
The distance in the Z direction between and is changed. The Z stage 68 can be fixed at a desired position by moving the sensor drive mechanism 80 in the Z direction by, for example, the pulse motor 70. The focal depth adjusting means such as the Z stage 68 may be provided on the table 110 on which the subject 20 is placed. Further, each motor including the pulse motor 70 in the following description is controlled by a control means such as a microcomputer.

If optical observation of the specimen 20 is desired, an optical microscope 72 for optically observing the specimen 20 and a photographing device 74 for taking a photomicrograph thereof may be attached to the horizontal frame 66. Good.

A multistage sensor drive mechanism 80 is attached below the Z stage 68, as shown in FIG. This sensor drive mechanism 80 is
The θ-axis goniometer 82 for setting the incident angle, the thickness absorbing spencer 84 of the sensor drive mechanism 80, the θ-axis goniometer 8
2, a ψ-axis goniometer 86 for fine adjustment for adjusting the inclination of the ultrasonic sensor 1 in a direction perpendicular to the swing center axis C ₀ , and an x for correcting the focal position of the ultrasonic sensor 1 in the x-axis direction.
An axial stage 88 and a z-axis spencer 90 for correcting the focal position of the ultrasonic sensor 1 in the z-axis direction are sequentially stacked and attached.

A holder 78 of the ultrasonic sensor 1 is attached to the lowermost z-axis spencer 90 of the sensor drive mechanism 80 via an adapter 76. Adapter 76
The holder 78 can be attached and detached by, for example, screwing in or fixing the screw.

The θ-axis goniometer 82 tilts the ultrasonic sensor 1 in the θ direction in order to set the ultrasonic wave incident angle, and includes a drive mechanism section 92 and a tilting table 94. The θ-axis goniometer 82 is preferably driven by a stepping motor 96. When the main shaft (not shown) of the θ-axis goniometer 82 is rotated by the driving of the stepping motor 96, a worm gear (not shown) provided on the main shaft is moved inside the drive mechanism section 92.
The tilt table 9 is meshed with a worm wheel (not shown) formed along the curved surface 94a of the tilt table 94.
4 is tilted in the θ direction. As a result, the tilt table 94
The ultrasonic sensor 1 is tilted in the θ direction through the respective components attached to the lower horizontal surface 94b of and is stopped at an appropriate incident angle according to various measurements.

When setting the incident angle by the θ-axis goniometer 82, it is preferable that the reflected wave from the surface 20a of the subject be efficiently received by the ultrasonic sensor 1. Specifically, it is preferable that the plane formed by the incident wave and the reflected wave between the subject surface 20a and the ultrasonic sensor 1 be perpendicular to the subject surface 20a.

Therefore, in the present embodiment, the Ψ-axis goniometer 86 is attached to the lower horizontal surface 94b of the tilt table 94 of the θ-axis goniometer 82 via the spencer 84. The Ψ-axis goniometer 86 is for tilting the ultrasonic sensor 1 in the Ψ direction, and includes a drive mechanism section 98 and a tilt table 100 similar to the drive mechanism section 92 and the tilt table 94 of the θ-axis goniometer 82. There is.
However, a main shaft (not shown) in the drive mechanism unit 98 is manually driven by a knob 102 connected to the main shaft. Then, the tilt table 100 is manually operated by the knob 102.
The ultrasonic sensor 1 is tilted in the Ψ direction through the respective components attached to the lower horizontal surface 100a of the and is stopped at an appropriate tilt angle.

Further, when the ultrasonic sensor 1 is tilted in the θ direction by the θ-axis goniometer 82, it is preferable to position the focal point of the ultrasonic sensor 1 on the central axis of the tilt. This is because the subject 12
This is because the focus is always kept at a fixed position. For this purpose, in this embodiment, the Ψ-axis goniometer 8 is used.
An x-axis stage 88 and a z-axis spencer 90 are provided below 6. Here, the x-axis stage 88 is for correcting the focal position of the ultrasonic sensor 1 in the x-axis direction,
The Ψ-axis goniometer 86 is attached to the lower horizontal surface 100a of the tilt table 100 so as to be slidable in the x direction. By manually sliding the x-axis stage 88 in the x-direction, the focal position of the ultrasonic sensor 1 is adjusted in the x-axis direction.

The z-axis spencer 90 attached to the x-axis stage 88 is for aligning the focal position of the ultrasonic sensor 1 in the z-axis direction with the swing center axis C ₀ of the θ-axis goniometer 82. Yes, it is manually expanded and contracted in the z-axis direction. These x-axis stage 88 and z-axis spencer 90
The focal position of the ultrasonic sensor 1 by the θ-axis goniometer 8
It is located on the rocking center axis of the No. 2.

On the other hand, the base 60 of the UMSM is provided with a multi-stage table generally designated by reference numeral 110, as shown in FIG.

In this multi-stage table 110, an X stage 112 for aligning the subject 20 under the sensor 1 and a dual type goniometer 114 for adjusting the inclination of the subject 20 are sequentially stacked from the lower stage. Installed.

The positioning X stage 112 is preferably driven in the X direction by a stepping motor 116. As a result, the entire multi-stage table 110 is driven in the X direction, and the multi-stage table 110 is positioned.

It is preferable that the surface 20a of the subject placed on the upper surface of the multi-stage table 110 is horizontal with respect to the driving direction X of the multi-stage table 110. Therefore, in this embodiment, the multi-stage table 110 is provided with the dual-type goniometer 114. This dual type goniometer 114
Is an object mounting table 118 as an upper structure thereof.
And a goniometer 120 as a lower structure. The goniometer 120 has a tilt table 122, and the lower surface of the subject mounting table 118 is fixed to the upper plane of the tilt table 122.

When the knob 126 connected to the main shaft 124 of the goniometer 120 is manually rotated, the goniometer 1
A worm gear (not shown) provided on the main shaft 124 inside the gear 20 meshes with a worm wheel (not shown) formed along the curved surface 122a of the tilt table 122 to tilt the tilt table 122. Along with this, the subject mounting table 118 is also tilted, so that the knob 126
The surface 20a of the subject can be kept horizontal in the driving direction X of the multi-stage table 110 by appropriate rotation.

When the UMSM is provided with the optical microscope 72 and the photographing device 74, an X moving mechanism 128 and a Y moving mechanism for moving the multistage table 110 below the optical microscope 72 are provided below the multistage table 110. Moving mechanism 1
Place 30. These XY movement mechanisms 128, 130
Are preferably driven by stepping motors 132 and 134 to move the multi-stage table 110 in the XY directions.

According to the UMSM of the third embodiment, the ultrasonic sensor 1 can be accurately focused and the reliability of measurement can be improved.

Although the three embodiments of the present invention have been described above, the present invention is not limited to these. For example, the piezoelectric element group 2 of the array type cylindrical transducer 12
In No. 2, it is not always necessary to give a delay time to all the piezoelectric elements 24. For example, when scanning an extremely small area on the subject surface 20a, it is not necessary to give a delay time to the piezoelectric element 24 sufficiently separated from the area.
On the other hand, the piezoelectric element 40 of the planar transducer 14 does not necessarily have to be one. For example, when the area of the wave transmitting / receiving surface 18 is relatively large, the piezoelectric element 40 may be divided into a plurality of parts so that only the piezoelectric element at a position corresponding to the ultrasonic wave incident region on the subject surface 20a is driven. Good.

Further, in order to form the spectrum intensity distribution and the spectrum phase distribution, various measuring instruments generally used for spectrum analysis may be used instead of the FFT analyzer 54 and the calculator 59. For example, when the signal emitted by the pulsar 38 is a burst signal, a measuring instrument combining a spectrum analyzer and a tracking generator may be used instead of the FFT analyzer 54.

When a burst signal of a specific frequency is used as described above, it is necessary to sweep the frequency, and therefore it is necessary to transmit ultrasonic waves a plurality of times during measurement. However, also in this case, since the mechanical two-dimensional scanning of the ultrasonic sensor 1 is not required, the measurement can be performed at a higher speed than the conventional technique.

Furthermore, the ultrasonic sensor 1 of the present invention used for the UMSM is not limited to the UMSM having the configuration in the above-mentioned embodiment, but can be used as a sensor for an apparatus for executing ultrasonic spectroscopy.

[0104]

As described above, according to the ultrasonic sensor of the present invention and the ultrasonic spectrum microscope using the ultrasonic sensor, it is possible to linearly scan an object without mechanically scanning the ultrasonic sensor. It is possible to perform multi-point measurement by transmitting ultrasonic waves once for a short time. Therefore, the time required for measurement is significantly reduced, and high-speed measurement is possible.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an ultrasonic sensor according to a first embodiment of the present invention and an ultrasonic spectrum microscope using the same, and is a conceptual diagram in which an array type cylindrical transducer is used on a transmitting side. .

FIG. 2 is a perspective view showing an array type cylindrical transducer in FIG.

FIG. 3 is an explanatory diagram for explaining transmission / reception of ultrasonic waves of an array type cylindrical transducer by an input signal processing circuit or an output signal processing circuit.

FIG. 4 is a diagram showing an example of film thickness measurement by the ultrasonic spectrum microscope of FIG. 1, including (A) and (B);
Is a diagram showing a spectrum intensity distribution, and (B) is a diagram showing a spectrum phase distribution.

FIG. 5 is a diagram schematically showing an ultrasonic sensor according to a second embodiment of the present invention and an ultrasonic spectrum microscope using the ultrasonic sensor, and is a conceptual diagram in which an array type cylindrical transducer is used on a receiving side. .

6 is a block diagram showing a circuit configuration example on the output side of the ultrasonic sensor in FIG.

7 is a diagram showing an example of measuring the phase velocity by the ultrasonic spectrum microscope of FIG. 5, and is a diagram showing the relationship between the incident angle and the phase.

FIG. 8 is an explanatory diagram showing the relationship between the width in the longitudinal direction of the planar transducer of the ultrasonic sensor of the present invention and the incident angle component.

9 is a diagram showing the output characteristics of the ultrasonic sensor with respect to the incident angle component in FIG.

10 is a diagram showing the output characteristics of the ultrasonic sensor with respect to the incident angle component in FIG.

FIG. 11 is an explanatory diagram for explaining the incident angle selection ability of the ultrasonic sensor of the present invention.

FIG. 12 is a front view showing the overall configuration of the ultrasonic spectrum microscope of the present invention.

FIG. 13 is an enlarged view showing the sensor drive mechanism and the multistage stage in FIG. 9 in an enlarged manner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic sensor, 12 ... Array type cylindrical transducer (1st wave transmission / reception means), 14 ... Planar transducer (2nd wave transmission / reception means), 16 ... Cylindrical planar wave transmission / reception surface, 18
... planar wave transmitting / receiving surface, 20 ... object, 20a ... object surface, 20b ... linear scanning line, 22 ... piezoelectric element group, 2
4 ... Piezoelectric element, 26, 28 ... Electrode, 30 ... Piezoelectric body, 32
a, 32b, 32c ... Delay material, 34a ... Input signal processing circuit (input signal processing means), 34b ... Output signal processing circuit (output signal processing means), 38 ... Pulsar (high frequency oscillation means), 54 ... FFT (intensity spectrum) Forming means, phase spectrum forming means), 82 ... θ stage (angle control means), 86 ... Ψ stage (tilting means), 88 ... x-axis stage (focus position adjusting means) 110
... table, 112 ... X stage (moving means).

Claims (21)

[Claims] 1. A first and a second wave transmitting / receiving means, one of which is used as a wave transmitting side to transmit a high frequency ultrasonic wave to a surface of a subject by applying a high frequency signal, and the other receives the same. A transmission / reception-independent ultrasonic sensor used as a wave side, which receives reflected ultrasonic waves from a subject and outputs an electric signal corresponding to the intensity of the reflected ultrasonic waves; , A plurality of ultrasonic piezoelectric elements, each of which has a piezoelectric element group arranged in an array at equal intervals so as to independently generate a piezoelectric effect, and a high frequency ultrasonic wave to be emitted by the piezoelectric element group. In order to make a sound wave a focused wave, it has a cylindrical wave transmitting / receiving surface whose longitudinal direction is the array direction of the arrayed array; the second wave transmitting / receiving means is an ultrasonic piezoelectric element having a flat piezoelectric surface, and Having a plane wave transmitting / receiving surface; Nsa. 2. The ultrasonic sensor according to claim 1, wherein the first and second transmitting / receiving means are integrally formed. 3. The piezoelectric element of the first wave transmitting / receiving means has a piezoelectric body sandwiched between a pair of electrodes, and the surface of the piezoelectric body is formed into a cylindrical surface. Alternatively, the ultrasonic sensor described in 2. 4. The piezoelectric element of the first wave transmitting / receiving means has a piezoelectric body sandwiched between a pair of electrodes, and the surface of the piezoelectric body is formed in a planar shape. The ultrasonic sensor described. 5. A member forming at least one of a pair of electrodes of each piezoelectric element of the first wave transmitting / receiving means and a member forming a piezoelectric body is composed of a plurality of members. The ultrasonic sensor according to claim 3 or 4, wherein the piezoelectric element is integrally formed. 6. The super element according to claim 1, wherein the piezoelectric element group of the first wave transmitting / receiving means has a delay member having the cylindrical surface wave transmitting / receiving surface. Sound wave sensor. 7. The piezoelectric element of the second wave transmitting / receiving means is formed by sandwiching a piezoelectric body having a planar piezoelectric surface between a pair of planar electrodes. The ultrasonic sensor according to item 1. 8. The ultrasonic sensor according to claim 1, wherein the piezoelectric element of the second wave transmitting / receiving means has a delay member having the planar wave transmitting / receiving surface. . 9. The length L of the piezoelectric element of the second wave transmitting / receiving means in an arbitrary direction is expressed by the following formula: L ≧ (1 / sin β) · (V / ω) (where V is an ultrasonic wave propagation medium). Inside sound velocity, ω is the time frequency of the ultrasonic wave transmitted by the ultrasonic sensor, or the frequency of the minimum intensity part in the spectrum intensity distribution of the reflected ultrasonic wave received by the ultrasonic sensor, β is the incident angle of the ultrasonic sensor When the angle between the normal of the plane wave transmitting / receiving surface of the second wave transmitting / receiving means and the normal of the surface of the subject is θ, the second wave transmitting / receiving means receives a wave. The ultrasonic sensor according to any one of claims 1 to 8, wherein the incident angle component of the ultrasonic wave is a value indicating that it is only in the range of θ ± β. 10. A first transmitting / receiving wave so that ultrasonic waves transmitted from arbitrary integer N number of adjacent piezoelectric elements forming at least a part of the piezoelectric element group are focused at one focal point. 2. An input signal processing means for applying a predetermined time difference to a high frequency signal to be applied to each piezoelectric element of the means and applying it to each piezoelectric element.
10. The ultrasonic sensor according to any one of 1 to 9. 11. An electric signal corresponding to the intensity of a reflected wave reflected from a focal point from electric signals output from arbitrary integer N adjacent piezoelectric elements forming at least a part of the piezoelectric element group. 2. The output signal processing means for synthesizing the electric signals output from the respective piezoelectric elements of the first wave transmitting / receiving means by giving a predetermined time difference so that the above is formed. 10. The ultrasonic sensor according to any one of 1 to 9. 12. A linear scanning line by focusing a high frequency ultrasonic wave on each measuring point with respect to an object in which a virtual linear scanning line formed by arranging a plurality of measuring points on a straight line extends on the surface. An ultrasonic spectrum microscope that linearly scans a subject along a line and forms an intensity spectrum whose intensity is shown as a function of frequency based on an electric signal obtained from each measurement point; A table to be placed so that the high frequency ultrasonic waves to be transmitted from the first transmitting / receiving means are incident on the linear scanning line, and the reflected wave from the subject for this incident wave is the second transmitting / receiving means. 10. The ultrasonic sensor according to any one of claims 1 to 9, which is arranged so as to be received by an ultrasonic wave; a high-frequency oscillating means for oscillating a high-frequency signal as an input signal of the ultrasonic sensor; A high-frequency ultrasonic wave to be transmitted from at least a part of the piezoelectric elements of the first transmitting / receiving means of the ultrasonic sensor is focused on each measurement point while linearly scanning the subject along the linear scanning line. Input signal processing means for applying a predetermined time difference to the high frequency signal of the high frequency oscillating means and applying it to at least a part of piezoelectric elements of the first wave transmitting / receiving means; second wave transmitting / receiving of the ultrasonic sensor An ultrasonic spectrum microscope, comprising: an intensity spectrum forming means for forming an intensity spectrum of the electric signal output from the piezoelectric element of the means. 13. A high-frequency ultrasonic wave is transmitted to a linear scanning line with respect to an object having a virtual linear scanning line extending on the surface, in which a plurality of measurement points are arranged in a straight line, and the linear scanning line is transmitted. The object is linearly scanned by forming the reflected wave output for each measurement point based on the reflected wave from, and an intensity spectrum showing the intensity of the reflected wave for each measurement point as a function of frequency is formed. An acoustic wave spectrum microscope; a table on which an object is to be placed; a high frequency ultrasonic wave to be transmitted from the second wave transmitting / receiving means to be incident on a linear scanning line, and the object to be incident on this incident wave The ultrasonic sensor according to any one of claims 1 to 9, wherein the reflected wave from the ultrasonic wave sensor is arranged to be received by the first wave transmitting / receiving means;
High-frequency oscillating means for applying this high-frequency signal to the piezoelectric element of the second transmitting / receiving means of the ultrasonic sensor; and an electric signal output from at least a part of the piezoelectric element of the first transmitting / receiving means of the ultrasonic sensor. Based on the output of the reflected wave of at least a part of the piezoelectric element of the first wave transmitting / receiving means, a predetermined electric wave is formed so as to form an electric signal corresponding to the intensity of the reflected wave reflected from each measurement point. An ultrasonic spectrum microscope, comprising: an output signal processing means for giving a time difference and synthesizing; an intensity spectrum forming means for forming an intensity spectrum thereof based on the synthesized reflected wave output. 14. A phase spectrum forming means for forming a phase spectrum, the phase of which is shown as a function of frequency, based on the electric signal output from the piezoelectric element of the second wave transmitting / receiving means of the ultrasonic sensor. The ultrasonic spectrum microscope according to claim 12 or 13, characterized in that. 15. The high frequency signal oscillated by the high frequency oscillating means is a wide band pulse signal so that the high frequency ultrasonic wave to be emitted from the ultrasonic sensor is a wide band pulse wave. The ultrasonic spectrum microscope according to item 1. 16. The high frequency signal oscillated by the high frequency oscillating means is a burst signal oscillated while sweeping the frequency so that the high frequency ultrasonic wave to be emitted from the ultrasonic sensor becomes a burst wave. Item 15. The ultrasonic spectrum microscope according to any one of items 12 to 14. 17. The linear scanning line is moved along the surface of the object in the x direction when the direction of the surface of the object is the xy direction and the extending direction of the linear scanning line on the surface of the object is the y direction. 17. The apparatus according to claim 12, further comprising a moving unit that mechanically moves at least one of the ultrasonic sensor and the table relative to the other. The described ultrasonic spectrum microscope. 18. An incident angle or a reception angle defined by an angle formed by a normal line direction of the planar wave transmission / reception surface of the second wave transmission / reception unit and a normal line direction of the surface of the subject is made variable. The ultrasonic spectrum microscope according to any one of claims 12 to 17, further comprising: angle control means for tilting the second transmitting / receiving means with respect to a normal line direction of the surface of the subject. 19. The angle control means tilts the first and second wave transmitting / receiving means integrally about a central axis of the tilt parallel to the extending direction of the linear scanning line. The ultrasonic spectrum microscope according to claim 18. 20. The angle control means for integrally tilting the first and second wave transmitting / receiving means positions the focal point of the ultrasonic wave transmitted by the first wave transmitting / receiving means on the tilt center axis line. 20. The ultrasonic spectrum microscope according to claim 19, further comprising focus position adjusting means for integrally moving the first and second transmitting / receiving means in at least one direction. 21. The focus position adjusting means integrates the first and second transmitting / receiving means in a direction orthogonal to the moving direction and the normal direction of the surface of the subject at the time of aligning the focus. 21. The ultrasonic spectrum microscope according to claim 20, further comprising tilting means for tilting the lens.