JPH06194157A - Positioning control method, facing method, tunneling microscope using it, and recording/reproducing device - Google Patents

Abstract

PURPOSE:To easily measure the distance between the sample surface and a piezoelectric element by changing the cantilever type piezoelectric element at its natural frequency, and changing the admittance of the piezoelectric element. CONSTITUTION:A cantilever type piezoelectric element 1 formed with a Si substrate 2 and a sample 7 are arranged, and the element 1 is fixed to another expanding piezoelectric element 3. The bimorph type element 1 is driven by an AC power source 5 to make bending movement. The admittance of the element 1 can be measured by a voltmeter 6. The distance between the element 3 and the element 1 can be controlled by a variable DC power source 4. When voltage is applied to the element 3 from the power source 4 and the tip of the element 1 is brought into contact with the sample 7, the natural frequency is changed, and the admittance is changed. The element 3 is adjusted so that the element 1 is kept in no contact with the surface of the sample 7, then the bending movement of the piezoelectric element 1 is performed at the natural frequency by the power source 5. If the applied voltage when the element 1 is brought into contact with the sample 7 and the displacement quantity at the natural frequency are found, the distance between the stationary point at the tip of the element 1 and the surface of the sample 7 can be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cantilever type piezoelectric element driven by a reverse voltage effect, and a position control method for measuring a distance from a measuring object using the same, and further, a method of using the same. The present invention relates to a face-to-face matching method and a recording / reproducing device to which the same is applied.

[0002]

2. Description of the Related Art In recent years, a semiconductor pressure sensor using a semiconductor as a mechanical structure in the background of semiconductor process technology,
Mechanical electrical devices (micromechanics) such as semiconductor acceleration sensors and microactuators have come into the limelight.

Characteristic features of such an element are that it is possible to provide a small-sized and high-precision mechanical mechanism component, and since the semiconductor wafer is used, the element and the electric circuit can be integrated on the Si wafer. Further, by manufacturing the semiconductor process as a base, it can be expected that the productivity is improved by batch processing of the semiconductor process. In particular, there is a cantilever type piezoelectric element using a piezoelectric thin film, which can control extremely fine movements, so
It is applied to a scanning tunneling microscope (hereinafter referred to as STM) that can directly observe the molecular level.

For example, S using a cantilever type piezoelectric element proposed by Kuwait et al. Of Stanford University.
TM probe (IEEE Micro Electro
Mechanical Systems, pl88-
199, Feb, 1990). As shown in FIG. 12, a back surface of the Si wafer 1 is partially removed to form a silicon membrane, thin films of Al4 and ZnO5 are sequentially laminated on the surface, a bimorph cantilever is formed, and then a reaction is performed from the back surface. By removing the silicon membrane and the etching protection layer (silicon nitride film) on the surface of the wafer by dry etching, a bimorph cantilever type piezoelectric element for STM probe displacement is manufactured. At the free end of the upper surface of this cantilever, a probe 1 for detecting a tunnel current is provided.
Is attached to obtain a good STM image.

An atomic force microscope (hereinafter abbreviated as AFM) to which the STM technique is applied has been developed [Binning
et al. , Phys. Rev. Lett. , 5
6, 930 (1986)], and STM, it has become possible to obtain surface irregularity information. The AFM detects the force from the amount of bending by the cantilever (elastic body) that supports the probe that is brought closer to the sample surface to a distance of 1 nanometer or less receives the force acting between the sample and the probe. Then, the three-dimensional shape of the surface is observed with a resolution of nanometer or less by scanning the surface of the sample while controlling the distance between the sample and the probe so as to keep this force constant. A
Unlike the STM, the FM does not require the sample to have electrical conductivity, and an insulating sample, particularly a semiconductor resist surface or a biopolymer, can be observed in the order of atoms and molecules, and thus is expected to be widely applied. .

Further, the information on the atomic force of the AFM is detected and detected from the shift from the natural frequency of the cantilever while the probe and the sample surface are brought close to the distance at which the atomic force can be generated. A method of doing so has also been proposed (Japanese Patent Laid-Open No. 63-309802).

On the other hand, by using the STM method, observation and evaluation of semiconductor or polymer materials in atomic order and molecular order and fine processing (EE Ehrichs, 4th I
international Conference o
n Scanning Tuning Micr
oscopy / spectroscopy, '89, S
13-3) and application of the recording / reproducing apparatus to various fields have been studied. Among them, the application to computer calculation information and the like for which the demand for a recording device having a large capacity is increasing is being studied. This is because the miniaturization of the recording device has been desired along with the progress of the semiconductor process technology and the miniaturization of the microprocessor and the improvement of the calculation capability.

For the purpose of satisfying these requirements, the shape of the surface of the recording medium is changed by applying a voltage from a converter composed of a tunnel current generating probe which is present on a driving means whose distance from the recording medium can be finely adjusted. An information processing apparatus has been proposed in which the minimum recording area is 10 ⁻⁴ μm ² by recording and writing information and reading the information by detecting the change in tunnel current due to the change in shape (U
SP4575822).

The object of the present invention is to
This is to easily measure the distance between the sample surface and the cantilever type piezoelectric element by using M or the cantilever type piezoelectric element used for AFM.

The above is the object of the present invention, and it is an object of the present invention to provide a positioning control method and a surface alignment method and a recording / reproducing apparatus using the same in order to achieve this.

[0010]

According to the positioning control method of the present invention, at least one piezoelectric layer for changing the displacement of the cantilever in a plane orthogonal to the longitudinal direction, and a voltage is applied to the piezoelectric layer. A positioning control method using a cantilever type piezoelectric element having an electrode for
The cantilever is displaced at its natural frequency, and the distance from the sample surface is measured by the admittance change of the piezoelectric element.

Further, it is characterized in that the distance from the sample surface is measured from the frequency characteristic of the admittance of the piezoelectric element.

The face-matching method of the present invention comprises at least one piezoelectric layer for changing the displacement of the cantilever in a plane orthogonal to the longitudinal direction, and an electrode for applying a voltage to the piezoelectric layer. A surface alignment method using a cantilever-type piezoelectric element, wherein at least two or more of the cantilevers are provided on the same substrate, the cantilevers are displaced by the natural frequency, and a sample is obtained by changing the admittance of the piezoelectric element at the natural frequency. It is characterized in that the distance between the substrate and the surface is measured, and the plurality of measured distances are driven so as to approximate or coincide with each other so that the surface of the substrate and the sample are aligned.

A cantilever-type piezoelectric element having at least one piezoelectric layer for changing the displacement in a plane orthogonal to the longitudinal direction of the cantilever and an electrode for applying a voltage to the piezoelectric layer. A surface alignment method used, wherein at least two or more of the cantilevers are provided on the same substrate, the distance from the sample surface is measured from the frequency characteristics of the admittance of the piezoelectric element, and the plurality of measured distances are approximate or coincident. It is characterized in that it is driven in such a manner that the surface of the substrate and the sample are aligned.

In the tunnel microscope and the recording / reproducing apparatus, the above-mentioned positioning control method and surface alignment method are used, respectively.

[0015]

The present invention is characterized in that the cantilever type piezoelectric element is used and the free end is displaced at the natural frequency or a frequency in the vicinity thereof. Since the energy can be minimized by vibrating at the natural frequency, it is possible to move the free end very greatly even with the same energy. However, when the free end comes into contact with the sample surface, the vibration mode changes, so that the admittance of the cantilever piezoelectric element changes. Positioning by the piezoelectric element is performed while measuring this admittance. That is, it is a feature of the present invention that both the purpose of driving the cantilever type piezoelectric element and the purpose of measuring the distance can be compatible.

In the present invention, the distance between the free end of the cantilever type piezoelectric element and the sample can be measured without using optical means or a special sensor. In addition, the distance can be easily measured by simply performing electrical measurement using the same cantilever type piezoelectric element as in the related art, and the device can be easily made into an IC.

[0017]

Embodiments of the present invention will now be described with reference to the drawings.

[Embodiment 1] FIG. 1 shows a cantilever type piezoelectric element 1 formed on a Si substrate 2 and a sample 7. This cantilever type piezoelectric element 1 is fixed to another piezoelectric element 3 which expands and contracts.

FIG. 2 shows the piezoelectric cantilever type piezoelectric element 1.
It is a figure which shows the structure of in detail.

This is manufactured on a Si substrate by a normal IC manufacturing process and anisotropic etching of silicon. Insulating layer 8 and lower gold electrode 9, Z on Si substrate 2
nO piezoelectric layer 10, middle metal electrode 11, ZnO piezoelectric layer 1
2. The bimorph cantilever type piezoelectric element is constructed by a structure in which the upper gold electrode 13 is laminated in this order. At this time, when the upper electrode 13 and the lower electrode 9 are short-circuited and a voltage is applied between the middle electrode and the middle electrode, the free end of the cantilever-type piezoelectric element 1 bends due to the inverse piezoelectric effect.

The displacement amount at this time is expressed by the following equation.

ΔZ / ΔV = [3L²d₃₁Y_Z(B²-A²)] / {4 (b−a) [YM (a³-B ³ + C³) + YZ (C³-B³)}} ・ ・ ・ ・ ・ (1) At this time, L is the length to the free end of the cantilever, YM
Is the Young's modulus of the electrode thin film, YZ is the Young's modulus of the piezoelectric thin film,
2 × a is the thickness of the middle electrode, ba is the thickness of the piezoelectric body, and cb is the thickness of the upper and lower electrodes.

Further, the first-order natural frequency Fr at this time is expressed by the following equation.

Fr = 0.162 × (E / ρ) ^1/2 × t / L ² (2) where E is the Young's modulus of the cantilever and ρ is the density of the cantilever. t is the film thickness of the cantilever.

For example, if the length of the cantilever is 300 μ
m, the thickness of the middle electrode is 0.2 μm, and the thickness of the piezoelectric body is 0.3
μm, the thickness of the upper and lower electrodes is 0.1 μm, d ₃₁ = 4.0 pC
/ N, and Young's modulus of gold is 7.8 × 10 ¹⁰ N / m
² , the density ρ of the cantilever is 1.11 × 10 ⁴ Kg / m ³
Then ΔZ / ΔV = 1.59 μm / V Fr = 6470 Hz.

Next, when the bimorph type cantilever type piezoelectric element 1 is driven by the AC power source 5 shown in FIG. 1, the bending movement is started. At this time, the voltmeter 6 can simultaneously measure the admittance of the piezoelectric element. A signal of V0sinωt is output from this alternating current, and the amplitude and frequency can be changed. Further, the piezoelectric element 3 is configured so that the variable DC power source 4 can control the distance in the Z direction of the cantilever type piezoelectric element.

Now, when the cantilever type piezoelectric element is at a distance far enough from the sample 7 (not in contact with the sample), the frequency response of the bending motion displacement is shown in FIG.
As shown in (a). That is, in the frequency band (A in the figure) that is sufficiently lower than the natural frequency, there is a displacement amount calculated by the equation (1). Further, the frequency at which the maximum displacement amount (B in the figure) at this time is obtained matches the frequency calculated by the equation (2). At the same time, when the admittance of the cantilever type piezoelectric element is measured by the circuit shown in FIG. 1, it becomes as shown in FIG.

This is because the energy is minimized when the drive frequency and the natural frequency of the cantilever match, and therefore the maximum point (B in the figure) of the admittance matches the natural frequency described above.

FIG. 4 is a diagram showing the applied voltage amplitude dependency of the tip displacement of the cantilever type piezoelectric element 1 at points A and B, which is calculated by equation (1) at point A lower than the natural frequency. It is the amount of displacement. On the other hand, when driven at the natural frequency (point B), a much higher displacement amount can be obtained. For more information,
It is possible to obtain a displacement amount that is approximately double the mechanical Q value. This mechanical Q value is determined by the shape, material, etc., and reaches several tens to several thousands.

Next, in FIG. 1, a voltage is applied from the DC power source 4 to the piezoelectric element 3 to bring the tip of the cantilever type piezoelectric element into contact with the sample 7. The frequency dependence of the admittance at this time is as shown in FIG. It is not possible to see the local maximum seen at the natural frequency B point described above. This is because, as shown in FIG. 8, the tip of the cantilever-type piezoelectric element 1 contacts and changes from the cantilever state to a state close to a cantilever state, which changes the natural frequency.

From the above, by monitoring the change in admittance, it can be easily determined whether or not the tip of the cantilever type piezoelectric element 1 contacts the surface of the sample 7.

Next, the positioning control method will be described.

In FIG. 1, a cantilever type piezoelectric element 1
The piezoelectric element 3 is adjusted so as not to contact the surface of the sample 7. After that, the AC power source 5 causes the cantilever to bend at a natural frequency. For example, if the length of the cantilever is 30
0 μm, the thickness of the middle electrode is 0.2 μm, the thickness of the piezoelectric body is 0.3 μm, the thickness of the upper and lower electrodes is 0.1 μm, and d ₃₁ = 4.
When 0 pC / N and the mechanical Q value are 70, ΔZ / ΔV is the following value.

ΔZ / ΔV = 1.59 μm / V (when the natural frequency is below) ΔZ / ΔV = 111 μm / V (when the natural frequency) At this time, when the dependence of the admittance on the applied voltage is measured, As shown in FIG.

Since the admittance changes when the free end of the cantilever comes into contact with the sample surface, the distance between the stationary point at the tip of the cantilever and the sample surface can be obtained by knowing the applied voltage and the amount of displacement at the natural frequency at that time. Can be easily measured.

FIG. 7 is a plot of the frequency at which the maximum value of the admittance is obtained when the cantilever type piezoelectric element 1 is gradually brought closer to the sample 7 using the piezoelectric element. A significant frequency shift is seen when they come into contact. Also by this method, it is possible to accurately confirm whether it is in the contact state or the non-contact state, and it is possible to perform accurate positioning.

As described above, the cantilever-type piezoelectric element is flexed at the natural frequency to perform positioning, and the external force is used to approach the sample surface to determine the natural frequency of the cantilever-type piezoelectric element. With any of the positioning methods, the positioning can be performed accurately.

[Embodiment 2] In the present embodiment, a surface alignment method using the cantilever type piezoelectric element shown in FIG. 1 will be described.

FIG. 9 shows two cantilever type piezoelectric elements 1.
Are formed on the Si substrate 2. The sample 7 is held by a plurality of Z-direction driving elements 102, and the Z axis and the tilt can be changed. These are the support 101
It is fixed at. The plurality of cantilever piezoelectric elements 1 are respectively connected to the actuator drive circuit 103 and the admittance detection circuit 104, and are configured so that the Z direction position control circuit 105 can measure the admittance change at the natural vibration frequency and the natural frequency. ing. Z
The direction drive circuit 106 is for driving the plurality of Z direction drive elements 102, and is feedback-controlled by a signal from the Z direction position control circuit 105.

First, the two cantilever type piezoelectric elements 1 are bent by the actuator drive circuit 103 at the natural frequency. At this time, the distance from the surface of the sample 7 is measured by the admittance detection circuit 104 in the same manner as in the first embodiment. As a result, the Z-direction drive circuit 106 operates the Z-direction drive element 102 so that the Z-direction position control circuit 105 makes the distances between the two cantilevers-type piezoelectric elements 1 and the sample 7 match or approximate. In such a method, the two cantilever piezoelectric elements 1 and the surface of the sample 7 can be equidistant.

It is also possible to measure the frequency dependence of the two admittances and match or approximate the distances. In this way, good alignment can be achieved by both measuring methods. For example, a cantilever type piezoelectric element 1
When there are a plurality (3 or more) of the cantilever type piezoelectric elements, it is possible to perform good surface alignment by adjusting the measurement results of the cantilever type piezoelectric elements of 3 or more points so as to be the same or approximate.

[Embodiment 3] In this embodiment, an STM apparatus using the cantilever type piezoelectric element shown in FIG. 1 will be described.

FIG. 10 is a diagram showing the structure of the STM device of this embodiment. The Z-direction drive element 102 is mounted on the support base 101.
The XY scanning mechanism 110 is installed, and the sample 7, which is an observation object, can move in the XY directions. Further, the cantilever piezoelectric element 1 formed on the Si substrate 2 is fixed to a position facing the sample by a support 101, and a probe 108 is formed at the tip of the cantilever. The XY scanning mechanism 110 is driven by the XY driving circuit 107, and Z
The direction driving element 102 is driven by the Z direction driving circuit 106. A bias voltage is applied between the sample 7 and the probe 108 by the voltage application circuit 113, and the tunnel current flowing between them is detected by the tunnel current detection circuit 109. Further, in the Z direction, feedback control is performed by the actuator drive circuit 103 so that the value of the tunnel current flowing between the sample 7 and the probe 108 becomes constant. All of these circuits are uniformly controlled by the microcomputer 112, and the observation result is displayed. ST configured as above
In the M apparatus, first, the distance between the surface of the sample 7 and the probe 108 is measured by measuring the admittance of the cantilever piezoelectric element 1 using the same method as in the second embodiment. At this time, the displacement amount of the cantilever piezoelectric element 1 used in this example is ΔZ / ΔV = 1.59 μm / V (when the natural frequency is less than or equal to) ΔZ / ΔV = 111 μm / V (when the natural frequency is Therefore, when performing a high-speed STM operation, it is suitable to perform the movement in the Z-axis direction by driving only the cantilever type piezoelectric element 1. In this case, since the cantilever piezoelectric element 1 is driven at a frequency equal to or lower than the natural frequency, the sample 7 and the probe 108 are positioned so that they are not 1 μm apart. After that, Z-axis driving is performed at a frequency equal to or lower than the natural frequency.

When the above driving is performed, the distance between the sample 7 and the probe 108 can be easily measured. That is, by combining the measurement of the distance by detecting the tunnel current (several nm or less) and the measurement of the distance by the admittance of the cantilever piezoelectric element 1 (several tens of μm or less), it is possible to cope with unevenness on the order of tens of μm from the atomic level Information can be obtained, and measurement can be performed with high accuracy over a wide range of distances.

In the STM, a phenomenon in which a tunnel current is difficult to flow due to contamination of the tip of the probe is often seen even though the probe is in contact with the sample. In such a case, erroneous information is often obtained as the STM image, but according to the present invention, it is possible to easily determine whether or not the probe is in contact.
This has the advantage that the state of the probe can be monitored in advance and a more accurate STM image can be obtained.

[Embodiment 4] In this embodiment, a recording / reproducing apparatus to which the above-described positioning method and surface alignment method are applied will be described.

FIG. 11 is a diagram showing the structure of the recording / reproducing apparatus of this embodiment. Since this embodiment uses the STM configuration shown in FIG. 10, the same configurations are assigned the same numbers as in FIG.

Inside the support base 101, a Z-direction driving element 102 and an XY mounted on the Z-direction driving element 102.
A scanning mechanism 110 is provided. A substrate 111 is provided on the XY scanning mechanism 110, and the electrode 1 is provided on the substrate 111.
16 and a recording medium 117 are installed. The XY scanning mechanism 110 is driven by an XY direction drive circuit 107, and a recording voltage is applied to a recording medium 117 by a recording voltage application circuit 114, or a pulse voltage for reproducing comfort or reading a recording bit by a voltage circuit 115. Is applied. The Z-direction driving element 106 is driven by the Z-direction driving circuit 106, and the tilt of the recording medium 117 on the XY scanning mechanism 110 and the Z-axis can be adjusted.

A Si substrate 2 of 10 mm square is used, and a plurality of cantilever type piezoelectric elements 1 are formed on the Si substrate 2.
Are attached to the support 101 in a direction facing the recording medium 117. A probe 108 is provided at the free end of each cantilever type piezoelectric element 1. The tunnel current that individually flows through each probe 108 is detected by the current detection circuit 109. Each cantilever is driven by the actuator drive circuit 103. Also, the admittance is detected by the admittance detection circuit 104 even during driving, and these pieces of information are stored in the Z direction position control circuit 105.
It is used to control the positions of the probe 108 and the recording medium 117 by the. All the above circuits are controlled by the microcomputer 112.

The recording medium 117 used was one in which an organic recording layer was laminated on an Au thin film (2500 Å) epitaxially grown on a mica substrate. As the organic recording layer, an LB film of squarylium-bis-6-octiazulene (1
Layers) were used. As the method for forming the LB film, the method disclosed in JP-A-63-161552 was used.

First, the surface of each cantilever type piezoelectric element 1 is aligned with the recording medium 117 by using the method shown in the second embodiment so that the positions thereof are approximate or equivalent.
At this time, the probes 1 on all the cantilever-type piezoelectric elements 1
It is necessary to adjust so that the distance between the recording medium 107 and the recording medium 107 is within a range of displacement (stroke ± 1 μm) equal to or less than the natural frequency of the cantilever. By adjusting in this way, all the cantilever type piezoelectric elements 1 can detect the tunnel current by following the irregularities of the recording medium 117 by the reverse voltage effect of itself. As described above, the alignment and the face matching are performed.

Next, the recording / reproducing method in this embodiment will be described.

First, one of the probes 108 is placed on the anode side, and the electrode 1
A pulse voltage of 5 V was applied with 16 as the cathode side to generate recorded bits. Next, a voltage of 1 V was applied between the probe 108 and the Au thin film while the distance between the probe 108 and the recording layer was held by the cantilever type piezoelectric element 1, and the tunnel current was measured to be about 0.5 mA. It was confirmed that the current flows and the recording bit is formed.

Next, recording was continuously performed using the recording / reproducing apparatus described above. Recording was performed by sequentially driving a plurality of cantilevers at a speed of 5 msec per bit for one cantilever, and confirming the recorded contents, it was confirmed that an error occurred in each recorded bit by the plurality of cantilever piezoelectric elements 1. I couldn't do it.

[0055]

According to the positioning control method and the surface alignment method of the present invention, the positioning and the surface alignment can be performed with high accuracy. In the tunnel microscope and the recording / reproducing apparatus using these methods, the probe is used. There is an effect that the control can be performed well.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a position control method of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a cantilever type piezoelectric element 1 in FIG.

3A and 3B are diagrams showing a relationship between displacement-frequency change and admittance-frequency in a free state of the cantilever-type piezoelectric element 1.

FIG. 4 is a diagram showing displacement characteristics of the cantilever type piezoelectric element 1.

FIG. 5 is a diagram showing admittance when the cantilever type piezoelectric element 1 is in contact.

FIG. 6 is a diagram showing a change in admittance due to contact of the cantilever type piezoelectric element 1.

FIG. 7 is a diagram showing a change in natural frequency due to contact of the cantilever piezoelectric element 1.

FIG. 8 is a schematic diagram showing a contact state of the cantilever type piezoelectric element 1.

FIG. 9 is a diagram showing a state of face-to-face matching which is an object of the present invention.

FIG. 10 is a diagram showing a configuration of an embodiment of a tunnel microscope according to the present invention.

FIG. 11 is a diagram showing a configuration of an embodiment of a recording / reproducing apparatus according to the present invention.

FIG. 12 is a diagram showing a structure of a probe used in STM.

[Explanation of symbols]

 1 Cantilever Type Piezoelectric Element 2 Si Substrate 3 Piezoelectric Element 4 DC Power Supply 5 AC Power Supply 6 Voltmeter 7 Sample 101 Support 102 Z Direction Drive Element 103 Actuator Drive Circuit 104 Admittance Detection Circuit 105 Z Direction Position Control Circuit 106 Z Direction Drive Circuit 107 XY direction drive circuit 108 Probe 109 Current detection circuit 110 XY scanning mechanism 111 Substrate 112 Microcomputer 113 Voltage application circuit 114 Recording voltage application circuit 115 Reproduction voltage application circuit 116 Electrode 117 Recording medium

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Ryo Kuroda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshiyuki Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Yu Nakayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (8)

[Claims] 1. A cantilever-type piezoelectric element comprising at least one piezoelectric layer for changing displacement in a plane orthogonal to the longitudinal direction of the cantilever, and an electrode for applying a voltage to the piezoelectric layer. The positioning control method used is characterized by displacing the cantilever at its natural frequency and measuring the distance from the sample surface by changing the admittance of the piezoelectric element. 2. The positioning control method according to claim 1, wherein the distance from the sample surface is measured from the frequency characteristic of the admittance of the piezoelectric element. 3. A cantilever-type piezoelectric element comprising at least one piezoelectric layer for changing a displacement in a plane orthogonal to the longitudinal direction of the cantilever, and an electrode for applying a voltage to the piezoelectric layer. A surface alignment method used, wherein at least two or more of the cantilevers are provided on the same substrate, each cantilever is displaced at its natural frequency, and the distance from the sample surface is changed by the admittance change of the piezoelectric element at the natural frequency. A face-to-face aligning method, characterized in that each substrate is measured and driven so that the plurality of measurement distances are approximated or coincident with each other, and the substrate and the sample are aligned. 4. A cantilever-type piezoelectric element comprising at least one piezoelectric layer for changing a displacement in a plane orthogonal to the longitudinal direction of the cantilever, and an electrode for applying a voltage to the piezoelectric layer. A surface alignment method using, wherein at least two or more of the cantilevers are provided on the same substrate, the distance from the sample surface is measured based on the frequency characteristic of the admittance of the piezoelectric element, and the plurality of measured distances are approximate or coincident. The surface alignment method is characterized in that the substrate and the sample are surface-aligned by being driven as described above. 5. A cantilever-type piezoelectric element comprising at least one piezoelectric layer for changing a displacement in a plane orthogonal to the longitudinal direction of the cantilever, and an electrode for applying a voltage to the piezoelectric layer. A tunnel having a probe attached to the free end of the cantilever-type piezoelectric element, the sample being arranged at a position facing the cantilever-type piezoelectric element, and outputting information on the unevenness of the sample surface through the probe. In a current microscope, the distance between the cantilever type piezoelectric element and the sample surface is measured using the method according to claim 1 or 2, and the sample surface is scanned by the cantilever type piezoelectric element based on the measurement result. Tunnel microscope characterized by. 6. A cantilever-type piezoelectric element comprising at least one piezoelectric layer for changing displacement in a plane orthogonal to the longitudinal direction of the cantilever, and an electrode for applying a voltage to the piezoelectric layer. A substrate provided with at least a plurality of the cantilevers, and a probe attached to each free end of the cantilever-type piezoelectric element, a sample is arranged at a position facing the cantilever-type piezoelectric element, and the probe is interposed. In a tunnel current microscope that outputs information on unevenness of a sample surface by using a method according to claim 3 or 4, the cantilever-type piezoelectric element and the sample are surface-aligned, and then the sample surface is cantilever-type. A tunnel microscope characterized by scanning with a piezoelectric element. 7. A cantilever-type piezoelectric element comprising at least one piezoelectric layer for changing displacement in a plane orthogonal to the longitudinal direction of the cantilever, and an electrode for applying a voltage to the piezoelectric layer, A recording medium having a probe attached to the free end of a cantilever-type piezoelectric element, a recording medium disposed at a position facing the cantilever-type piezoelectric element, and recording or reproducing on or from the recording medium surface via the probe. In the apparatus, the distance between the cantilever type piezoelectric element and the recording medium surface is measured by using the method according to claim 1 or 2, and the recording medium surface is scanned by the cantilever type piezoelectric element based on the measurement result. A recording / reproducing apparatus characterized by the above. 8. A cantilever-type piezoelectric element comprising at least one piezoelectric layer for changing displacement in a plane orthogonal to the longitudinal direction of the cantilever, and an electrode for applying a voltage to the piezoelectric layer, A substrate provided with at least a plurality of cantilevers, and a probe attached to each free end of the cantilever-type piezoelectric element, a recording medium is disposed at a position facing the cantilever-type piezoelectric element, In a recording / reproducing apparatus for performing recording or reproduction on the surface of a recording medium by using the method according to claim 3 or 4, the surface of the recording medium is cantilevered after the cantilever-type piezoelectric element and the recording medium are face-aligned with each other. Type recording / reproducing apparatus characterized by scanning with a piezoelectric element.