JPH0972889A - Ultrasonic measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the elastic modulus even of a sample having film thickness about one to several times the wavelength of ultrasonic waves used in measurement. SOLUTION: First ultrasonic wave transmitting-receiving means 8, 10 converge ultrasonic waves to a fine spot to allow them to be incident on a sample 12 and sample reflecting waves are converted to a reflection signal to be sent out and second ultrasonic wave transmitting-receiving means 9, 11 allow ultrasonic waves to be incident on the sample 12 as plane waves and sample reflecting waves are converted to a reflection signal. The relative distances of the sample 12 and the first ultrasonic wave transmitting-receiving means 8, 10 are changed to measure complex V(z) data and a surface wave operation means 20c calculates the sound velocity of Rayleigh waves on the basis of the complex V (z) data. The frequencies of high frequency burst waves are changed to measure the intensities of the reflection signals at the respective frequencies and a vertical wave operation means 20d calculates the sound velocity of vertical waves from an interference curve. An elastic constant operation means 20e calculates the elastic constant of the sample 12 from the sound velocity of Reileigh waves and that of vertical waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic measuring apparatus for measuring elastic properties of a sample by using ultrasonic waves, and particularly to a sample whose film thickness is thinner than several times the wavelength of the ultrasonic wave. The present invention relates to an ultrasonic measuring device.

[0002]

2. Description of the Related Art An apparatus for converging an ultrasonic wave to enter a sample, receiving a reflected wave from the sample, and creating an ultrasonic image based on the intensity of the reflected wave, or a convergence point of the ultrasonic wave is Z.
V obtained from the reflected waves of the sample at a plurality of positions displaced in the direction
An ultrasonic microscope is known as an apparatus for measuring the elastic properties of a minute portion of a sample using a (Z) curve. This type of ultrasonic microscope measures only the intensity of the reflected wave from the sample. On the other hand, an ultrasonic measuring device for detecting the intensity and phase of the reflected wave has been developed in order to obtain more information about the elastic properties of the sample. For example, Japanese Patent Laid-Open No. 5-
No. 26854 describes an ultrasonic measuring device that detects the intensity and phase of a reflected wave of a sample and analyzes the elastic properties of the sample.

FIG. 5 is a block diagram of an ultrasonic measuring device configured to detect a phase. The ultrasonic measuring apparatus shown in the figure constantly outputs a continuous wave of a constant frequency from the reference signal oscillator 101, and a control unit 103 that receives a transmission trigger from the computer 102 receives a frequency of several tens of cycles of the frequency of the reference signal oscillator 101. An on / off signal corresponding to the time width is output to the analog switch 104 in synchronization with the transmission trigger. The analog switch 104 switches according to ON / OFF of the ON / OFF signal. When the on / off signal is ON, the analog switch 104 is connected to the terminal a side, and the signal generated by the reference signal oscillator 101 is output to the circulator 105 to generate a transmission burst signal. This transmission burst signal passes through the circulator 105 and is applied to the transducer 106. The transmission burst wave is electroacoustic converted by the transducer 106 and converted into ultrasonic waves. This ultrasonic wave propagates through the acoustic lens 107 and is incident on the sample 109 placed on the sample stage 108. A space between the acoustic lens 107 and the sample 109 is filled with a coupler liquid 110 for the propagation of ultrasonic waves. The ultrasonic wave incident on the sample 109 is reflected by the sample 109, propagates again through the coupler liquid 110 and the acoustic lens 107, and is converted into an electric signal by the transducer 106. Hereinafter, this signal is referred to as a reflection signal.

The reflected signal passes through the circulator 105 and is amplified by the preamplifier 111 to produce two multiplication units 112a and 1a.
Enter in 12b. The multiplier 112a multiplies the continuous wave output from the reference signal oscillator 101 by the reflected signal and outputs an in-phase component. In the multiplication unit 112b, the continuous wave output from the reference signal oscillator 101 is output by 90 ° in the phase shift unit 113.
The quadrature phase component is output by multiplying the phase-changed signal and the reflected signal.

The signal output from the reference signal oscillator 101 is s
Let in (ωt). ω is frequency and t is time. Since the phase of the reflected signal is delayed with respect to the transmission due to the elastic properties of the sample, the time required for propagating through the acoustic lens and the coupler liquid, and so on, if this phase delay is φ, then Bsin
It can be written as (ωt-φ). B is the intensity of the reflected signal. Therefore, the in-phase output u ₁ of the multiplication unit 112a and the quadrature phase output u ₂ of the multiplication unit 112b are as follows.

[0006]

[Equation 1]

[0007]

[Equation 2]

Since φ is a constant, sin φ and cos φ are also constants, so that u ₁ and u ₂ have a DC component and a frequency of 2ω. Except for the 2ω component, sin and cos of the phase delay φ of the reflected signal are You can take it out.

The in-phase output of the multiplying unit 112a and the quadrature phase output of the multiplying unit 112b have low-pass filters 114a and 114b respectively removing the 2ω component, leaving only the DC components corresponding to sin φ and cos φ.

The A / D converters 115a and 115b A / D-convert the detection outputs of the in-phase and quadrature phases, respectively, and convert the phase detection output of the sample reflection into a digital signal and store it in the memory of the computer 102. To do. The computer 102 stores the sample reflection si
The phase and the reflection intensity are calculated from the nφ and cosφ components.

The Z scanning unit 116 changes the distance between the acoustic lens and the sample according to a command from the computer 102. The computer 102 causes the Z scanning unit 116 to use the acoustic lens 10.
A complex V (z) curve can be obtained by measuring the phase and intensity of the reflected signal while changing the distance between 7 and the sample 109.
The pupil function of the acoustic lens P (k _z) Tosureba following relationship between V (z) curve and the reflection function of the sample R (k _z).

[0012]

(Equation 3)

K _z is the z component of the ultrasonic wave number k, and θ
Is the incident angle of the ultrasonic wave, k _z = k cos θ, and there is a Fourier transform relationship. The pupil function of the acoustic lens is
Normally, the phase is flat, and the intensity is a curve in which the incident angle of ultrasonic waves is 0 at maximum and gradually decreases. Therefore,
As a result of inverse Fourier transform of the complex V (z) curve, peaks appear at critical angles of longitudinal waves and transverse waves, and phase changes of 360 ° at the critical angle of Rayleigh waves, so the critical angle and Snell's law The sound velocity of longitudinal wave, transverse wave and Rayleigh wave can be calculated from. If the sound velocity v _{1 of} the longitudinal wave and the sound velocity v _{s of} the transverse wave are known and the density ρ of the sample is known, the Young's modulus E, the transverse elastic modulus G, and the Poisson's ratio ν which are elastic constants can be calculated by the following equations.

[0014]

(Equation 4)

[0015]

However, the above-mentioned method of measuring the elastic constant by ultrasonic waves has the following drawbacks. That is, when the thickness of the sample is thinner than about 5 times the wavelength of the ultrasonic wave, or when there is a film of the same thickness on the substrate, when trying to measure the elastic constant of the sample or the film, the Lamb wave is generated in the film. Surface waves of a plate wave, which is called as, are generated at various sound velocities, and the V (z) curve becomes a very complicated shape as shown in FIG. 6 due to the excitation of a large number of plate waves. As a result, the complex V
(Z) The intensity of the inverse Fourier transform of the curve has a valley at the critical angle of each surface wave, and the phase changes by 360 °, so that the critical angle between the longitudinal wave and the transverse wave cannot be detected and the elastic constant cannot be measured. It will be possible.

The present invention has been made in view of the above points,
An object of the present invention is to provide an ultrasonic measuring device capable of measuring an elastic constant even for a sample having a film thickness of about 1 to several times the wavelength of ultrasonic waves used for measurement.

[0017]

In order to achieve the above object, the present invention takes the following measures. The present invention corresponding to claim 1 relates to a burst wave oscillating means for generating a high frequency burst wave of variable frequency, and a high frequency burst wave applied from the burst wave oscillating means is converted into an ultrasonic wave and converged to a minute spot to form a sample. A first ultrasonic wave transmitting / receiving means for transmitting a reflected signal obtained by converting the reflected wave from the sample into an electric signal again, and a high frequency burst wave applied from the burst wave oscillating means into an ultrasonic wave to generate a plane wave. A second ultrasonic wave transmitting / receiving means for transmitting a reflected signal in which the reflected wave from the sample is converted into an electric signal again, and an ultrasonic wave between the first ultrasonic wave transmitting / receiving means and the sample. A distance changing means for changing the relative distance in the sound wave incident direction, and a distance changing means for changing the distance between the first ultrasonic wave transmitting / receiving means and the sample to obtain the first ultrasonic wave transmitting / receiving means. A complex V (z) measurement means for measuring the complex information of the reflected signals at the respective distances from the output reflected signal,
Interference curve measuring means for changing the frequency of the high frequency burst wave generated by the burst wave oscillating means and measuring intensity information of the reflected signal at each frequency from the reflected signal output from the second ultrasonic wave transmitting / receiving means. , The complex V
(Z) A memory for storing the complex information measured by the measuring means and the intensity information measured by the interference curve measuring means, and a surface for calculating the sound velocity of the Rayleigh wave of the sample based on the complex information stored in the memory. A wave calculation means, a longitudinal wave calculation means for calculating the sound velocity of the longitudinal wave of the sample based on the intensity information stored in the memory, a sound velocity of the Rayleigh wave calculated by the surface wave calculation means, and the longitudinal wave calculation means. An ultrasonic measuring device is constituted by the elastic constant calculating means for calculating the elastic constant of the sample from the sound velocity of the longitudinal wave calculated in step 1.

According to the present invention, in the case of a sample having a film thickness thicker than the wavelength of ultrasonic waves, the phase is 360 when the complex V (z) curve is measured and the inverse Fourier transform is performed on the complex V (z) curve. ° Paying attention that the largest angle among the changing angles is almost equal to the critical angle of Rayleigh wave,
The sound velocity v _{R of the} Rayleigh wave can be obtained from the complex V (z) curve.

When the intensity of the reflected signal from the sample is measured while changing the frequency by injecting a plane ultrasonic wave perpendicular to the surface of the sample, the reflected ultrasonic waves on the upper surface and the lower surface of the sample itself interfere with each other to change the frequency. The change causes strength. Assuming that the frequency interval Δf between the valleys of this interference curve and the sound velocity v ₁ of the longitudinal wave of the sample are d, the thickness of the film thickness of the sample is

[0020]

(Equation 5) Therefore, the sound velocity of longitudinal wave can be obtained. Between the speeds of sound of Rayleigh, longitudinal, and transverse waves

[0021]

(Equation 6) Therefore, we can calculate the shear wave velocity.

As described above, since the acoustic velocities of the longitudinal wave and the transverse wave are obtained, the elastic constant can be calculated from the equation (4). According to the present invention corresponding to claim 2, in the ultrasonic measuring device having the above-mentioned configuration, when measuring complex V (z) data, a high frequency burst wave generated by the burst wave oscillating means is sent to the first ultrasonic transmitting / receiving means. A switch is provided for inputting and inputting the high frequency burst wave generated by the burst wave oscillating means to the second ultrasonic wave transmitting / receiving means when the interference data is measured.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a diagram showing an embodiment in which the present invention is applied to an ultrasonic measuring device. This ultrasonic measuring device is C
The PU 1 notifies the oscillation frequency to the oscillation section 3 via the bus 2, and the oscillation section 3 capable of varying the oscillation frequency generates a continuous wave having a frequency designated by the CPU 1.

The first semiconductor switch 4 cuts off a part of the continuous wave sent from the oscillator 3 to generate a burst wave. The a terminal of the semiconductor switch 4 is connected to the a terminal of the second semiconductor switch 5. Second semiconductor switch 5
The amplifier 6 is connected to the other terminal b. By switching the connection terminal of the second semiconductor switch 5, input / output to / from the changeover switch 7 can be switched. A first transducer 8 for performing electroacoustic conversion is connected to a terminal of the changeover switch 7, and another b
The second transducer 9 is connected to the terminal.

The first transducer 8 is the acoustic lens 1
It is attached to one end surface of 0. The ultrasonic wave incident from one end surface of the acoustic lens 10 is irradiated onto the sample 12 as an ultrasonic wave which converges into a minute spot from the lens surface formed on the other end surface of the lens. The second transducer 9 is the rod 1
1 is attached to one end surface. The rod 11 irradiates the sample 12 with the ultrasonic wave incident from the second transducer 9 as a plane wave.

The sample 12 is placed in a water tank 14 on a sample table 13. The water tank 14 is filled with a coupler liquid 15 for propagating ultrasonic waves. The reflected wave from the sample 12 is received by the acoustic lens 10 and the rod 11,
Are converted into reflected signals by the transducers 8 and 9 and input to the amplifier 6 via the changeover switch 7 and the second semiconductor switch 5.

The output stage of the amplifier 6 has two multiplication units 16
a and 16b are connected in parallel. One of the two continuous waves output from the oscillator 3 is input to the multiplier 16a as the first reference signal. The other output obtained by dividing the continuous wave into two is input to the other multiplication section 16b as a second reference signal with a 90 ° phase delay through a 90 ° phase shift section 17 composed of, for example, a 90 ° hybrid. Multiplication unit 1
Low-pass filters 18a and 18b are connected to the output stages of 6a and 16b, respectively, for removing high-frequency components.

The low-pass filters 18a and 18b are set to have a cutoff frequency that can remove at least twice the frequency of the continuous wave output from the oscillator 3 during measurement.

The reflected signals that have passed through the low-pass filters 18a and 18b are A / D converted by the A / D converters 19a and 19b, and the respective converted outputs are input to the memory 20 through the bus 2.

Connected to the bus 2 are a control unit 21 for controlling the overall timing, a Z scanning unit 22 for changing the distance between the sample 12 and the acoustic lens 10, and a Z distance measuring unit 23 for measuring the moving distance. ing.

Here, in the memory 20, a V (z) measurement program 20a in which the processing content for measuring the complex V (z) curve is defined, and an interference in which the processing content for measuring the interference curve is defined. Measurement program 20b, complex V (z)
Complex V (z) analysis program 20c in which the processing content for determining the Rayleigh wave sound velocity from the curve is defined, Longitudinal wave sound velocity analysis program 20d in which the processing content for determining the sound velocity of the longitudinal wave from the interference curve is defined, Rayleigh wave An elastic constant calculation program 20e in which the processing content for calculating the elastic constant from the longitudinal sound velocity is defined is stored.

Next, the operation of the present embodiment configured as described above will be described with reference to the time chart shown in FIG. First, the V (z) measurement program 20a is activated to measure the complex V (z) curve of the sample 12.

Prior to the measurement, the CPU 1 issues a command to the changeover switch 7 through the bus 2 to connect the changeover switch 7 to the a terminal so that the burst wave is applied to the first transducer 8. On the other hand, the oscillator 3
Outputs a continuous wave of a constant frequency at the oscillation frequency designated by the CPU 1, as shown in FIG.

When the transmission trigger shown in FIG. 2B is input from the CPU 1 to the control unit 21, the control unit 21 synchronizes with the transmission trigger as shown in FIG. The first is an ON / OFF signal with a period width
Output to the semiconductor switch 4 of, and as shown in (d) of FIG.
A switching signal that turns off after several tens of nanoseconds is output to the second semiconductor switch 5.

The first semiconductor switch 4 has the ON and O states.
Switching according to the ON / OFF state of the FF signal,
When N, the signal generated by the oscillator 3 is output to the second semiconductor switch 5. In this way, the transmission burst signal shown in FIG. 2 (e) is created.

The second semiconductor switch 5 is connected to the first semiconductor switch 4 when the switching signal from the controller 21 is ON.
When the switching signal is OFF, the amplifier 6 is switched to. The transmission burst signal is the second
Is applied to the first transducer 8 through the changeover switch 7 while the semiconductor switch 5 of FIG.

The transmitted burst wave is electroacoustic converted by the first transducer 8 and converted into ultrasonic waves. This ultrasonic wave propagates through the acoustic lens 10, converges, passes through the coupler liquid 15, and enters the sample 12. The incident ultrasonic wave is the sample 12
Is reflected by the first transducer 8 and is propagated through the coupler liquid 15 and the acoustic lens 10 again, converted into an electric signal by the first transducer 8 and transmitted as a reflected signal. Here, as shown in FIG. 2F, in addition to the sample reflection component, the reflection signal includes transmission leakage, the first lens reflection component, the second lens reflection component, and the like.

When the second semiconductor switch 5 is connected to the b terminal, such a reflected signal is amplified by the amplifier 6 and input to the multiplication units 16a and 16b. Multiplication unit 16a
Then, the continuous wave output from the oscillator 3 is used as a reference signal for multiplication with the reflected signal, and the result is output. On the other hand, the second reference signal obtained by delaying the signal output from the oscillator 3 by 90 degrees in the phase shift section 17 is multiplied by the reflected signal in the multiplication section 16b,
The result is output. Each multiplication unit 16a, 16
The signals multiplied by b are low-pass filters 18a and 18b.
2 times the frequency component of the oscillator 3 is removed by
As shown in, a rectangular wave having a size corresponding to cos φ and sin φ is extracted. The outputs of the low-pass filters 18a and 18b thus phase-detected are A / D converter 1
Input to 9a and 19b. The phase-detected signal contains a large number of rectangular waves because there is internal reflection of the lens in addition to the reflection from the sample.

In the A / D converters 19a and 19b, the sample reflection is extracted from the large number of signals. Therefore,
As shown in (h), the control unit 21 creates an A / D conversion trigger signal whose timing is delayed by Td with respect to the transmission trigger, and inputs it to the A / D conversion units 19a and 19b as a trigger signal. The A / D converters 19a and 19b perform A / D conversion on the respective detection outputs to convert them into digital signals indicating the phase detection outputs of the sample reflection and store them in the memory.

By the above operation, the complex information at one Z position is acquired. Each time complex information at the Z position is acquired, a command is input from the CPU 1 to the Z scanning unit 22 to change the distance in the ultrasonic wave incident direction between the acoustic lens 10 and the sample 12. The above-described processing is repeated at each Z position, and the complex information cosφ and sinφ of the sample reflection are stored in the memory 20 as V (z) data together with the movement amount detected by the Z distance measuring unit 23.

The time delay amount Td from the start of transmission to the generation of the A / D conversion trigger can be set from the CPU 1 to the control unit 21. When the complex V (z) data is measured, the A / D conversion timing Td is first adjusted to the sample reflection position while looking at the oscilloscope or the like. However, the optimum timing of the A / D conversion changes as the distance between the acoustic lens 10 and the sample 12 changes. Therefore, the amount of movement in the Z direction from the measurement start position is ΔZ, the timing shift is ΔTd, and the acoustic velocity of the coupler is v.
Then, the CPU 1 calculates the A / D conversion timing by the following formula and changes the timing.

[0042]

(Equation 7)

Next, the interference measurement program 20b is activated to measure the interference data of the sample 12. First, the changeover switch 7 is turned on by a command from the CPU 1.
It connects with a terminal and it switches to the 2nd transducer 9 side. As a result, the transmission burst wave can be supplied to the second transducer 9.

Next, the control unit 21 to which the transmission trigger is inputted from the CPU 1 to the control unit 21 controls the first semiconductor switch 4 to generate a transmission burst signal, and the switch 7 switches the transmission burst signal to the second switch. Apply to the transducer 9. The second transducer 9 converts the transmitted burst wave into ultrasonic waves, and the planar ultrasonic waves perpendicular to the sample 12 are incident from the rod 11.

When the sample 12 is thinner than several times the wavelength of the ultrasonic wave, the reflected ultrasonic waves on the upper and lower surfaces of the sample itself interfere with each other. When the intensity of the reflected signal from the sample is measured while changing the frequency of the ultrasonic wave (transmission burst signal), the change in frequency causes strong and weak interference.

Therefore, while the interference data is being measured, the oscillation frequency of the oscillator 3 is continuously changed by the instruction from the CPU 1 to change the frequency of the ultrasonic wave. In such a state, the intensities of the reflected signals converted into the electric signals by the second transducer 9 are used as the multiplication units 16a, 16 in the subsequent stage.
The phase detection is performed in b, and the phase detection output is loaded into the memory 20 as interference data together with the frequency value.

The Z scanning unit 22 does not move while the interference data is being measured. When the measurement of the complex V (z) data is completed as described above, the complex V (z) analysis program 20c is activated. The CPU 1 operates based on the complex V (z) analysis program 20c, performs an inverse Fourier transform on the complex V (z) data that has already been measured and stored in the memory, and then performs an inverse Fourier transform curve as shown in FIG. To get. The phase is 3 as shown by the arrow in FIG.
The largest angle is selected from the incident angles of the ultrasonic waves that are changed by 60 °, and the sound velocity v _{R of the} Rayleigh wave is calculated by Snell's law by the following formula.

[0048]

(Equation 8)

When the measurement of the interference data is completed, the longitudinal wave analysis program 20d is activated. The longitudinal wave analysis program 20d recognizes the interference curve as shown in FIG. 4 from the interference data indicating the relationship between the signal intensity and the frequency of the reflected signal stored in the memory 20, and detects the arrow A, from the interference curve. The average value Δf of the intervals of the valleys shown by B, C, and D is obtained, and this Δf is substituted into the above-mentioned equation (5) to calculate the sound velocity v _{1 of the} longitudinal wave.

After the sound velocity v _{R of the} Rayleigh wave and the sound velocity v _{1 of the} longitudinal wave are obtained in this way, the elastic constant calculation program 20e is started to calculate the elastic constant. That is,
The transverse wave sound velocity v _S is obtained from the Rayleigh wave sound velocity v _R and the longitudinal wave sound velocity v ₁ from the formula (6), and the longitudinal wave sound velocity v _l and the transverse wave sound velocity v _S are substituted into the formula (4) to calculate the elastic constant. To do.

If the thickness of the sample 12 is thicker than about 5 times the wavelength of the ultrasonic wave, the acoustic constants of the longitudinal wave and the transverse wave are calculated only by the complex V (z) curve, and the elastic constant is calculated, as in the conventional case. .
As described above, according to the present embodiment, the complex V (z) curve is measured and the interference curve of the reflected signal due to the plane wave is measured, the Rayleigh wave sound velocity is obtained from the former, the longitudinal wave sound velocity is obtained from the latter, and the Rayleigh wave sound velocity is obtained. Also, since the elastic constant of the sample 12 is calculated from the longitudinal sound velocity, the elastic constant of a film having a thickness of several times the wavelength (about several tens of μm) can be measured.

In this embodiment, the phase detection is used for measuring the interference curve, but the measurement of the reflected signal strength is not limited to this. Since only the intensity data is used for the longitudinal wave sound velocity measurement, the interference curve may be acquired by intensity detection.

Further, the two devices of the acoustic lens and the rod are switched by a changeover switch, but it is also conceivable to connect and replace them by making them connectors. The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0054]

As described above in detail, according to the present invention, the Rayleigh wave sound velocity is obtained from the complex V (z) curve, the longitudinal wave sound velocity is obtained from the interference curve, and the elasticity of the sample is calculated from the Rayleigh wave sound velocity and the longitudinal wave sound velocity. Since the constant is calculated, it is possible to provide an ultrasonic measuring device capable of measuring the elastic constant even for a sample having a film thickness of about 1 to several times the wavelength of the ultrasonic wave used for measurement.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an ultrasonic measurement device according to an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the ultrasonic measurement device shown in FIG.

FIG. 3 is a diagram showing an inverse Fourier transform waveform of a complex V (z) curve.

FIG. 4 is a diagram showing an interference curve.

FIG. 5 is a configuration diagram of a conventional ultrasonic measurement device.

FIG. 6 is a diagram showing an inverse Fourier transform waveform of a complex V (z) curve.

[Explanation of symbols]

1 ... CPU, 2 ... Bus, 3 ... Oscillator, 4 ... First semiconductor switch, 5 ... Second semiconductor switch, 6 ... Amplifier, 7
… Changeover switch, 8… First transducer, 9
... second transducer, 10 ... acoustic lens, 11 ...
Rod, 12 ... Sample, 16a, 16b ... Multiplying section, 17 ...
Phase shift section, 18a, 18b ... Low-pass filter, 19a,
19b ... A / D converter, 20 ... Memory.

Claims (2)

[Claims] 1. A burst wave oscillating means for generating a variable frequency high frequency burst wave, and a high frequency burst wave applied from the burst wave oscillating means converted into ultrasonic waves, converged into a minute spot and made incident on a sample, A first ultrasonic wave transmitting / receiving means for transmitting a reflected signal obtained by converting the reflected wave from the sample into an electric signal again, and a high frequency burst wave applied from the burst wave oscillating means is converted into an ultrasonic wave and incident on the sample as a plane wave. Let
A second ultrasonic transmission / reception means for transmitting a reflection signal obtained by converting a reflected wave from the sample into an electric signal again, and a relative distance in the ultrasonic wave incident direction between the first ultrasonic transmission / reception means and the sample are shown. The distance changing means for changing the distance, and the distance changing means for changing the distance between the first ultrasonic wave transmitting / receiving means and the sample, and changing the distance at each distance from the reflection signal output from the first ultrasonic wave transmitting / receiving means. Complex V (z) measuring means for measuring the complex information of the reflected signal, and the reflected signal output from the second ultrasonic wave transmitting / receiving means by changing the frequency of the high frequency burst wave generated by the burst wave oscillating means, respectively. Interference curve measuring means for measuring the intensity information of the reflected signal at the frequency, the complex information measured by the complex V (z) measuring means, and the intensity information measured by the interference curve measuring means. Memory, a surface wave calculation means for calculating the sound velocity of the Rayleigh wave of the sample based on the complex information stored in the memory, and a sound velocity of the longitudinal wave of the sample based on the intensity information stored in the memory. Longitudinal wave calculation means, and elastic constant calculation means for calculating the elastic constant of the sample from the sound velocity of the Rayleigh wave calculated by the surface wave calculation means and the sound velocity of the longitudinal wave calculated by the longitudinal wave calculation means. An ultrasonic measuring device characterized by the above. 2. The ultrasonic measuring device according to claim 1, wherein when the complex V (z) data is measured, a high frequency burst wave generated by the burst wave oscillating means is input to the first ultrasonic wave transmitting / receiving means, An ultrasonic measurement device comprising a switch for inputting a high frequency burst wave generated by the burst wave oscillating means into the second ultrasonic wave transmitting / receiving means during measurement of interference data.