JPH06241778A - Surface observing method, record reproducing method, surface observing device and record reproducing device using these - Google Patents

Abstract

PURPOSE:To control the relative position not to be affected by the voltage application by detecting the change quantity of a chip tip position and the change quantity of the distance between an elastic body fitting position and a sample surface before and after the application of the voltage. CONSTITUTION:A chip 101 scans a sample 103 in the direction XY, the force applied in the direction Z is detected by a deflection quantity detecting device 106, it is outputted to a position detecting device 107, and the position change quantity in the direction Z at the tip of the chip 101 is obtained. The device 107 detects the position change quantity in the direction Z at the tip of the chip 101 when voltage is applied and outputs it to a differential amplifier 108 as a drift. A Z-direction position control device 110 receives the output of the amplifier 108, outputs it to a Z-direction drive amplifier 111, moves the position of a stage 115 in the direction Z, outputs the control signal to a Z-direction position detecting device 109, and outputs the drift quantity of the position of the sample 103 in the direction Z to the amplifier 108 while voltage is applied. The chip 101 and the sample 103 are approached, and the position of the tip of the chip 101 is determined at an optional position on the surface of the sample 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a tunneling current or force (atomic force) generated between a probe and a sample to observe the sample surface (Scanning Probe Microscopy. SPM), or uses this. The present invention relates to an information processing apparatus for recording / reproducing information on / from a sample surface, and particularly to a probe control mechanism.

[0002]

2. Description of the Related Art In these, the surface of a substance can be observed with atomic resolution, and the surface shape of metals, semiconductors, organic substances, etc. can be observed by using these devices.

More recently, in addition to simply observing the surface shape, it is said that the current-voltage characteristics of a current flowing by applying a voltage to a tip are measured, the electrical characteristics of the surface are changed by applying a voltage, or the surface is mechanically changed. Technology is well developed.

For example, a tip of the AFM is coated with a conductive material, the position of the tip is determined on the nanoscale by the operation of the AFM, and then a voltage is applied between the sample and the tip to measure the current, thereby obtaining a local current voltage. It is disclosed in JP-A-3-210465 that the measurement can be performed.

Further, when an image is obtained by the AFM operation and at the same time the current flowing when a voltage is applied to the tip is imaged at the same time as the AFM image, it is possible to obtain information on the surface shape and the conductivity corresponding thereto. Kaihei 3-27790
It is disclosed in Japanese Patent No.

Further, a method has been devised in which after the position is determined by the AFM operation, information is recorded on the medium by applying a voltage and the recording is read out by the current characteristic there.

[0007]

However, when a voltage is applied using a conductive tip in the AFM, the sample-
The electrostatic force acts between the tips, and the force acting between the tip and the sample is the sum of the atomic force and this electrostatic force. Therefore, the distance between the sample and the tip becomes shorter than the distance before the voltage is applied only by controlling the deflection amount of the elastic body such as the cantilever to be constant. In such a state, it is impossible to measure the correct current-voltage characteristic.

Further, when a voltage is applied to the tip to cause a physical or chemical change to record on the recording medium, or when the recorded information on the recording medium is read by a current flowing through the tip, an electrostatic force is applied. There is a problem that an electric field more than necessary is applied to the recording medium due to the pulling in due to the drawing, or the sample surface is mechanically damaged.

Such a problem generally occurs when an electrode is attached to the tip of an elastic body and an electric field is applied between the electrode and the sample.

The present invention has been made in view of the problems of the above-mentioned conventional technique, and the relative position of the tip end of the tip and the surface of the sample or the recording medium in the vertical direction is not affected by the voltage application. The purpose is to control.

[0011]

The surface observation apparatus of the present invention comprises a tip arranged so as to face a sample, voltage applying means for applying a voltage between the sample and the tip, and an elastic body for supporting the tip. A means for detecting the amount of flexure of the elastic body, a tip end position detecting means for detecting the position of the tip end from the amount of flexure of the elastic body, and a tip end position before and after the voltage application detected by the tip end position detecting means. A tip tip position change amount detecting means for detecting a change amount, a driving means for driving the elastic body mounting portion or the sample to adjust the distance between the elastic body mounting portion and the sample, and an elastic body mounting portion generated by the driving means. Measures the distance change between the sample before and after the voltage is applied and the tip end position change amount detected by the tip end position change amount detection means. A signal output means for outputting a signal for controlling the elastic body mounting portion or the sample driving means based on the change in the distance between the elastic body mounting portion and the sample detected by the outputting means, and a change in the applied voltage of the voltage applying means. And a correction means for correcting the fluctuation of the signal due to.

The recording apparatus of the present invention comprises a tip arranged to face the recording medium, a voltage applying means for applying a voltage between the recording medium and the tip, an elastic body for supporting the tip, and an elastic body. A means for detecting the amount of deflection, a tip tip position detecting means for detecting the tip tip position from the amount of deflection of the elastic body, and a change amount of the tip tip position before and after the voltage application detected by the tip tip position detecting means. Tip tip position change amount detection means, drive means for driving the elastic body mounting portion or the recording medium to adjust the distance between the elastic body mounting portion and the recording medium, and between the elastic body mounting portion generated by the driving means and the recording medium Of the distance between the elastic body mounting portion and the recording medium, which is based on the means for detecting the distance change before and after the application of the voltage and the tip end position change amount detected by the tip end position change amount detecting means. Signal output means for outputting a signal for controlling the elastic body mounting portion or the recording medium driving means based on the change in the distance between the elastic body mounting portion and the recording medium detected by the means for detecting And a correction means for correcting the fluctuation of the signal due to the change of the voltage.

The reproducing apparatus of the present invention comprises a tip arranged to face the recording medium, a voltage applying means for applying a voltage between the recording medium and the tip, an elastic body for supporting the tip, and an elastic body for supporting the tip. A means for detecting the amount of deflection, a tip tip position detecting means for detecting the tip tip position from the amount of deflection of the elastic body, and a change amount of the tip tip position before and after the voltage application detected by the tip tip position detecting means. Tip tip position change amount detection means, drive means for driving the elastic body mounting portion or the recording medium to adjust the distance between the elastic body mounting portion and the recording medium, and between the elastic body mounting portion generated by the driving means and the recording medium Of the distance between the elastic body mounting portion and the recording medium, which is based on the means for detecting the distance change before and after the application of the voltage and the tip end position change amount detected by the tip end position change amount detecting means. Signal output means for outputting a signal for controlling the elastic body mounting portion or the recording medium driving means based on the change in the distance between the elastic body mounting portion and the recording medium detected by the means for detecting And a correction means for correcting the fluctuation of the signal due to the change of the voltage.

The recording / reproducing apparatus of the present invention includes a tip arranged to face a recording medium, a voltage applying means for applying a voltage between the recording medium and the tip, an elastic body for supporting the tip, and an elastic body. Deflection amount detecting means, tip tip position detecting means for detecting the tip tip position from the elastic amount of the elastic body, and tip tip position change amount before and after voltage application detected by the tip tip position detecting means Tip tip position change amount detecting means, driving means for driving the elastic body mounting portion or the recording medium to adjust the distance between the elastic body mounting portion and the recording medium, and the elastic body mounting portion and the recording medium generated by the driving means. The distance between the elastic body mounting portion and the recording medium based on the means for detecting the distance change before and after the voltage application and the tip end position change amount detected by the tip end position change amount detecting means. A signal output means for outputting a signal for controlling the elastic body mounting portion or the recording medium driving means based on the change in the distance between the elastic body mounting portion and the recording medium detected by the means for detecting the change; And a correction means for correcting the fluctuation of the signal due to the change of the applied voltage.

The surface observing method of the present invention is a surface observing method performed by a surface observing device in which a tip supported by an elastic body is arranged so as to face a sample, and a voltage is applied between the sample and the tip. When adjusting the distance between the elastic body mounting portion and the sample by detecting the amount of deflection of the elastic body while applying, generate a signal for elastic body mounting portion-sample distance control based on the detected amount, It is characterized in that the fluctuation of the signal due to the change of the applied voltage is corrected.

A recording method and a reproducing method of the present invention are a recording and reproducing method performed by a recording and reproducing device in which a tip supported by an elastic body is arranged so as to face a recording medium. A voltage is applied between the elastic body and the deflection amount of the elastic body is detected, and a signal for controlling the distance between the elastic body mounting portion and the sample is generated based on the detected amount to determine the distance between the elastic body mounting portion and the recording medium. A feature of the present invention is that when adjustment is performed, a change in signal due to a change in applied voltage is corrected.

[0017]

In the above invention, the amount of change in the tip end position before and after the voltage is applied is detected from the amount of flexure of the elastic body before the voltage is applied between the tip and the sample or the recording medium and the amount of flexure of the elastic body before the voltage is applied. it can. Further, the amount of change in the distance between the elastic body mounting position and the sample surface or the recording medium surface before and after the voltage application can be detected from the control signal of the elastic body mounting portion driving device or the sample driving device. The position where the elastic body is attached or the position of the sample or the recording medium is controlled so that the amount of change becomes equal.

According to another aspect of the invention,
At the distance Za between the support of the elastic body and the sample, which is the shape signal or the distance servo signal in the conventional example, the error due to the small displacement Ze due to the deformation of the elastic body is corrected, and the accurate distance Z between the tip of the probe and the sample is used. A means for forming a shape signal or a distance servo signal will be provided (first feature).

[0019]

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

[Embodiment 1] In the following embodiment, a case where a voltage is applied between a sample and a tip by using a control mechanism according to the present invention to an AFM device having a conductive tip at the tip will be described. FIG. 1 is a diagram showing a device configuration of the present invention. In the following description, the in-plane direction parallel to the sample surface is X.
The −Y direction and the direction perpendicular to the sample surface will be described as the Z direction.

In this example, sample 1 to be observed
03 is mounted on the sample stage 115. The sample stage 115 is provided on the piezo element 114,
The piezo element 114 receives the control signals output by the Z-direction position control device 110 and the XY direction position control device 112, respectively, and receives the Z-direction drive amplifier 111 and the X-direction drive amplifier 111.
The sample stage 115 is moved by being displaced by the drive voltage output from the Y-direction drive amplifier 113.

The tip 101 is supported by a cantilever 102 which is an elastic body required to detect a force. In the AFM, the tip 101 is scanned on the sample 103 in the XY directions for observation. At this time, the force applied to the tip 101 in the Z direction is detected by the cantilever deflection amount detection device 106, and the difference between the detected value and a predetermined value to be stored is output. Further, the Z-direction position detecting device 109 detects the upper surface position of the sample 103.

Various methods can be used as the detecting method in the deflection amount detecting device 106.
There is an optical lever method in which the cantilever 102 is irradiated with a laser beam to detect the bending generated in the cantilever 102 by the difference in the reflection angle of the laser beam.

The amount detected by the deflection amount detecting device 106 is the cantilever 1 supporting the tip 101.
The bend angle is 02, and this amount is output to the position detection device 107 that detects the tip position of the tip 101.

When the tip 101 is in contact with the sample 103 and the position of the sample 103 in the Z direction changes, the detection signal generated in the position detecting device 107 by the bending of the cantilever 102 at that time is used to detect the cantilever 102. Tip 10 changed due to bending
It is possible to calibrate the positional relationship between 1 and the sample 103.

From the output of the deflection amount detecting device 106, the amount of positional change in the Z direction at the tip of the tip 101 can be obtained. The position detection device 107 detects the position change amount in the Z direction of the tip end of the tip 101 when a voltage is applied between the tip 101 and the sample 103 by the power supply 104 with the tip position of the tip 101 before voltage application as a reference. Then, this is output to the differential amplifier 108 as the amount of deviation.

The Z-direction position control device 110 receives the output of the differential amplifier 108, generates a Z-direction position control signal for the sample stage 115, and outputs it to the Z-direction drive amplifier 111, so that the Z-direction of the sample stage 115 is controlled. Move the position of.
At this time, the Z direction position control device 110 outputs the control signal to the Z direction position detection device 109. Sample stage Z
The direction position detecting device 109 can detect the positions of the sample stage 115 and the sample 103 in the Z direction from the value indicated by this signal. During the voltage application, the sample stage Z-direction position detection device 109 outputs the amount of deviation of the position of the sample in the Z direction from before the voltage application to the differential amplifier 108.

The tip 101 and the sample 103 are brought close to each other so that an atomic force acts, and the position of the tip of the tip 101 in the XY direction is set at an arbitrary position on the surface of the sample 103 by using the conventional AFM configuration and method. be able to.

The operation of this embodiment will be described in detail.

In FIG. 2, the position in the XY direction is determined and the XY position is determined.
FIG. 3 is a diagram showing the tip end portion of tip 101 and the surface of sample 103 when a voltage is applied between tip 101 and sample 103 after stopping the movement in the direction.

Even before the voltage is applied due to the interaction with the sample surface, the tip 101 and the cantilever 10
2 is at the positions indicated by 101A and 102A in the figure. Cantilever mounting portion 201 and tip 101 in this state
The distance in the Z direction from the tip of A is t ₀ , and the distance between the cantilever mounting portion 201 and the sample surface 103A in the Z direction is s ₀ . Further, the sample surface 103A and the tip 10 at this time
D ₀ When d ₀ the distance between 1A tip is given by _{d 0 = s 0 -t 0 ······} (1). At this time, the signal indicating the displacement amount of the tip position of the tip 101 of the position detection device 107 and the signal indicating the displacement amount of the sample stage 115 in the Z direction from the Z direction position detection device 109 are set to 0. The output of the differential amplifier 108 here is zero.

Next, in this state, Tip 101-Sample 1
A voltage is applied between 03. At this time, electrostatic force is generated, and the tip of the tip 101 supported by the cantilever 102 is attracted to the surface of the sample 103, and the cantilever 102 is
A bend occurs. The output of the position detection device 107 and the output of the operation amplifier 108 deviate from 0 due to the occurrence of the bending, and the Z-direction position control device 110 moves the position of the sample stage 115. Along with this movement, the sample 10 before the voltage is applied from the sample stage Z direction position detector 109
The signal of the displacement amount from the position of 3 is shifted from 0 and output to the differential amplifier 108.

In FIG. 2, the tip 101 is being applied with voltage.
And the position of the cantilever 102 is 101
B, 102B. The distance in the Z direction between the cantilever mounting portion 201 and the tip of the chip 101B is t, and the distance between the cantilever mounting portion 201 and the sample surface 103B in the Z direction is s. Further, at this time, the sample surface 103B and the tip 10
The distance from the 1B tip is d. At this time, the output of the position detection device 107 is t-t ₀ , and the output of the Z direction position detection device 109 is s-s ₀ . If the former is larger than the latter, the sample stage Z direction position control device 110 lowers the sample stage 115. If the latter is larger, the sample stage 115 is raised. By repeating this operation, tip 1
The positions of 01 and the cantilever 102 are stabilized at positions where the relationship of s−s ₀ = t−t ₀ (2) is satisfied. On the other hand, d is given by d = s-t (3), and when the change in the distance between the tip of the tip 101 and the surface of the sample 102 due to voltage application is Δd, Δd is Δd = D−d ₀ is given by (4). From equations (1) to (4), Δd = 0, and there is no change in the distance between the tip of the tip 101 and the sample 103 even when a voltage is applied.

By using the method as described above, it becomes possible to make the distance between the surface of the sample 103 and the tip of the tip 101 the same as that before the voltage application even by applying the voltage.

[Embodiment 2] FIG. 3 is a diagram showing the structure of a second embodiment of the recording / reproducing apparatus.

In this embodiment, the recording medium stage 315 (sample stage 11 in FIG. 1 has a structure similar to that of the first embodiment.
(Corresponding to No. 5), the writing and reading operations are performed on the recording medium 303 (corresponding to the sample 103 in FIG. 1) fixed on the recording medium 303. The writing and reading operations are controlled by the microcomputer 324.

Tip 301 and cantilever 30 in the figure
2, power supply 304, current detection device 305, deflection amount detection device 306, position detection device 307, differential amplifier 308, Z
Direction position detection device 309, Z direction position control device 310,
Z-direction drive amplifier 311, XY direction position control device 3
12, except that the XY drive amplifier 313 and the piezo element 314 are each controlled by the microcomputer 324, the tip 1 shown in FIG.
01, cantilever 102, power supply 104, current detection device 105, deflection amount detection device 106, position detection device 10
7, differential amplifier 108, Z direction position detection device 109, Z
Directional position control device 110, Z-direction drive amplifier 111,
The description is omitted because it is the same as the XY direction position control device 112, the XY direction drive amplifier 113, and the piezo element 114.

The microcomputer 324 inputs the detection results of the current detecting device 305, the position detecting device 307 and the Z direction position detecting device 309, and the power source 304, the Z direction position controlling device 310 and the XY direction position controlling device 31.
2 controls each output state. Microcomputer 32
4 sends information about the writing position and the reading position to the recording medium stage XY direction position control device 312 to determine the position of the recording medium in the XY direction. Further, the distance between the recording medium 303 and the tip of the tip 301 is determined by a signal from the position detection device 307 and is output to the Z direction position control device 310. In this way, the position of the tip 301 is determined.

The writing and reading operations for the recording medium 303 in this embodiment will be described in detail.

First, it is time to write on the recording medium 303. At this time, the power supply 304 gives an appropriate voltage from the state of the voltage or a specific bias voltage 0 according to the instruction of the microcomputer 324.
Apply between 01. At this time, by performing the same control as that described in the first embodiment, the tip 301-recording medium 303
Is kept at the same interval as before the application of the recording voltage. In the conventional recording / reproducing apparatus, the tip 301
In some cases, the distance between the recording media 303 changes and an appropriate electric field cannot be applied between the tips 301 and the recording media 303, or the tips 301 get stuck in the recording media 303 and the recording media 303 is destroyed. According to the present invention, an appropriate electric field can be applied between the tip 301 and the recording medium 303, and a good recording bit can be formed.

When reading from the recording medium 303, the microcomputer 32 is also started from the state of zero voltage.
According to the instruction of 4, the power supply 304 sets an appropriate voltage to the tip 30.
1-Applied between recording media 303. At this time, by performing the same control as described in the first embodiment, the tip 301
A space equal to that before the voltage application is maintained between the recording media 303. The current flowing in this state is measured by the current detection device 305 and the information is sent to the microcomputer 324. Also in this case, since the distance between the tip 301 and the recording medium 303 is appropriately maintained, correct reading can be performed, and the recording medium 303 can be prevented from being destroyed.

In each of the embodiments described above, Z
The signal for performing the directional position control is the position detection device 10
7 (307), the output of the Z-direction position detecting device 108 (308) is input according to the output of the differential amplifier 108 (308).
Since 08 has a configuration in which the output state is changed according to the result of comparing the respective inputs, the present invention can be configured by a simple comparison circuit, and it is natural that such a configuration is also possible.

[0043]

Since the present invention is constructed as described above, it has the following effects.

Even if a voltage is applied, by keeping the position of the tip end and the sample surface the same as before the voltage application, correct measurement can be performed even when measuring the current-voltage characteristic, and the medium can be measured. A correct electric field can be applied even when a voltage is applied. When a voltage is applied to the insulating thin film on the conductive substrate, it is possible to prevent the tip of the tip from penetrating into the thin film and destroying the thin film. Further, according to the present invention, when the voltage between the tip and the sample or the recording medium is determined after a certain voltage is applied and then the voltage is changed, the distance between the tip and the sample medium before the voltage change is changed by the voltage change. It is possible to keep the same condition as before.

[Brief description of drawings]

FIG. 1 is a diagram showing a device configuration of an embodiment of the present invention.

FIG. 2 is a tip portion of a tip 101 when a voltage is applied between the tip 101 and the sample 103 after the position in the XY direction of the embodiment shown in FIG. 1 is determined and the movement in the XY direction is stopped. 3 is a diagram showing the surface of a sample 103. FIG.

FIG. 3 is a diagram showing a configuration of a second embodiment of a recording / reproducing apparatus.

[Explanation of symbols]

 101, 301 Tip 102, 302 Cantilever 103, 402 Sample 104, 304 Power supply 105, 305 Current detection device 106, 306 Deflection detection device 107, 307 Position detection device 108, 308 Differential amplifier 109, 309 Z direction position detection device 110 , 310 Z direction position control device 111, 311 Z direction drive amplifier 112, 312 XY direction position control device 113, 313 XY direction drive amplifier 114, 314 Piezo element 115 Sample stage 201 Cantilever mounting part 303 Recording medium 315 recording medium stage 324 microcomputer

Front Page Continuation (72) Inventor Etsuro Takashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (7)

[Claims] 1. A tip arranged to face a sample, a voltage applying means for applying a voltage between the sample and the tip, an elastic body supporting the tip, and a deflection amount of the elastic body. Means for detecting, tip tip position detecting means for detecting the tip tip position from the amount of deflection of the elastic body, and tip for detecting the amount of change in tip tip position before and after voltage application detected by the tip tip position detecting means. Tip position change amount detecting means, driving means for driving the elastic body mounting portion or the sample to adjust the distance between the elastic body mounting portion and the sample, and voltage application between the elastic body mounting portion and the sample generated by the driving means. A means for detecting a change in the front-rear distance, a change amount in the tip end position detected by the tip end position change amount detecting means, and a change in the distance between the elastic body mounting portion and the sample. Elastic mounting portion detected by means of detecting -
A signal output unit that outputs a signal for controlling the elastic body mounting unit or the sample driving unit based on a change in the distance between the samples, and a correction that corrects the fluctuation of the signal due to the change of the applied voltage of the voltage applying unit. And a surface observation device. 2. A tip arranged to face a recording medium, a voltage applying means for applying a voltage between the recording medium and the tip, an elastic body supporting the tip, and a flexure of the elastic body. Means for detecting the amount, a tip end position detecting means for detecting the position of the tip end from the deflection amount of the elastic body, and a change amount of the tip end position before and after the voltage application detected by the tip end position detecting means. Tip tip position change amount detecting means, driving means for driving the elastic body mounting portion or the recording medium in order to adjust the distance between the elastic body mounting portion and the recording medium, and the elastic body mounting portion generated by the driving means and recording. Means for detecting a change in distance between before and after applying a voltage between media, tip tip position change amount detected by the tip tip position change amount detecting means, and the elastic body attachment And a signal output for outputting a signal for controlling the elastic body attaching portion or the recording medium drive means based on the change in the distance between the elastic body attaching portion and the recording medium detected by the means for detecting the change in distance between the recording medium and the recording medium. A recording apparatus, comprising: a recording unit and a correction unit that corrects a change in the signal due to a change in an applied voltage of the voltage applying unit. 3. A tip arranged to face a recording medium, a voltage applying means for applying a voltage between the recording medium and the tip, an elastic body supporting the tip, and a deflection of the elastic body. Means for detecting the amount, a tip end position detecting means for detecting the position of the tip end from the deflection amount of the elastic body, and a change amount of the tip end position before and after the voltage application detected by the tip end position detecting means. Tip tip position change amount detecting means, driving means for driving the elastic body mounting portion or the recording medium in order to adjust the distance between the elastic body mounting portion and the recording medium, and the elastic body mounting portion generated by the driving means and recording. Means for detecting a change in distance between before and after applying a voltage between media, tip tip position change amount detected by the tip tip position change amount detecting means, and the elastic body attachment And a signal output for outputting a signal for controlling the elastic body attaching portion or the recording medium drive means based on the change in the distance between the elastic body attaching portion and the recording medium detected by the means for detecting the change in distance between the recording medium and the recording medium. A reproducing apparatus comprising: means and a correcting means for correcting the fluctuation of the signal due to the change of the applied voltage of the voltage applying means. 4. A tip arranged to face a recording medium, a voltage applying means for applying a voltage between the recording medium and the tip, an elastic body supporting the tip, and a flexure of the elastic body. Means for detecting the amount, a tip end position detecting means for detecting the position of the tip end from the deflection amount of the elastic body, and a change amount of the tip end position before and after the voltage application detected by the tip end position detecting means. Tip tip position change amount detecting means, driving means for driving the elastic body mounting portion or the recording medium in order to adjust the distance between the elastic body mounting portion and the recording medium, and the elastic body mounting portion generated by the driving means and recording. Means for detecting a change in distance between before and after applying a voltage between media, tip tip position change amount detected by the tip tip position change amount detecting means, and the elastic body attachment And a signal output for outputting a signal for controlling the elastic body attaching portion or the recording medium drive means based on the change in the distance between the elastic body attaching portion and the recording medium detected by the means for detecting the change in distance between the recording medium and the recording medium. A recording / reproducing apparatus comprising: a means and a correcting means for correcting the fluctuation of the signal due to the change of the applied voltage of the voltage applying means. 5. A surface observation method performed by a surface observation device in which a tip supported by an elastic body is arranged so as to face a sample, wherein a voltage is applied between the sample and the tip and the elastic body When the amount of deflection is detected and a signal for controlling the distance between the elastic body mounting portion and the sample is generated based on the detected amount to adjust the distance between the elastic body mounting portion and the sample, A method for observing a surface, which comprises correcting the fluctuation of the signal. 6. A recording method performed by a recording / reproducing apparatus in which a tip supported by an elastic body is arranged so as to face a recording medium, wherein a voltage is applied between the recording medium and the tip and the elastic body is used. Of the applied voltage when detecting the amount of flexure of the elastic body and generating a signal for controlling the distance between the elastic body mounting portion and the sample based on the detected amount to adjust the distance between the elastic body mounting portion and the recording medium. A recording method, wherein the fluctuation of the signal due to a change is corrected. 7. A reproducing method performed by a recording / reproducing apparatus in which a tip supported by an elastic body is arranged to face a recording medium, wherein a voltage is applied between the recording medium and the tip and the elastic body is used. Of the applied voltage when detecting the amount of flexure of the elastic body and generating a signal for controlling the distance between the elastic body mounting portion and the sample based on the detected amount to adjust the distance between the elastic body mounting portion and the recording medium. A reproducing method characterized in that the fluctuation of the signal due to a change is corrected.