JPH07110969A - Face alignment method, position control mechanism and information processor with the mechanism - Google Patents

Abstract

PURPOSE:To obtain a face alignment method in which a scanning face and the surface of a recording medium are made precisely parallel even in a high- speed scanning operation. CONSTITUTION:By using a branching filter 41, a signal indicating a tunneling current is divided into a plurality of frequency bands including an arbitrary frequency region. Out of the plurality of divided frequency bands, a frequency (the natural frequency of a moving part for an X-Y-direction fine and coarse movement mechanism 22) which originates from the inclination of a recording medium 1 is selected, and the inclination of the recording medium 1 is corrected fine by using a second tilt mechanism 21 in such a way that the amplitude of the selected frequency becomes zero as far as possible. Concretely, a prescribed voltage is applied to a piezoelectric element constituting the second tilt mechanism 21, and the inclination of the recording medium 1 is corrected fine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface matching method,
In particular, the present invention relates to a surface alignment method suitable for an information processing apparatus having a plurality of probe electrodes using the principle of a scanning probe microscope or applying the scanning probe microscope.

Further, the present invention relates to a position control mechanism and an information processing apparatus having the mechanism, and particularly to a position control mechanism suitable for an information processing apparatus utilizing a physical phenomenon caused by bringing a probe and a recording medium close to each other. Regarding

[0003]

[Prior Art and Problems to be Solved by the Invention]

A. Regarding the Face-to-Face Method of the Present Invention [Prior Art] In recent years, with the development of the information society, the development of a large-capacity memory technology is in progress, and the principle of the scanning tunnel microscope is used or the scanning tunnel microscope is applied. A recording / reproducing device has been proposed (for example, Japanese Patent Laid-Open No. 61-80636).

A scanning tunneling microscope (G. Binnig et al., Helvetica Physica A developed by G. Binnig et al.
cta, 55, 726, 1982), when a voltage is applied between the metallic probe (probe electrode) and the sample (conductive substance), the probe is brought up to a distance of about 1 nm from the surface of the sample. The surface condition of the sample is observed by utilizing the fact that a tunnel current flows. Since the tunnel current is sensitive to changes in the distance between the probe and the sample, the amount of movement of the probe in the direction perpendicular to the sample surface when the probe is scanned to keep the tunnel current constant The state of the surface of the sample can be known by measuring or by measuring the change in the tunnel current when the probe is scanned while keeping the distance between the probe and the sample constant. Since the resolution of the sample in the in-plane direction is about 0.1 nm, if the principle of the scanning tunneling microscope is used, it is possible to perform high-density recording / reproduction on the atomic order (sub-nanometer) (see, for example, Japanese Patent Laid-Open Publication No. Sho. 63-204531, JP-A-63-1.
61552, JP-A-63-161553).

On the other hand, with the development of the scanning tunneling microscope technique, while detecting various other interactions depending on the distance between the probe and the sample, which are not limited to the tunnel current,
Techniques (scanning probe microscope technique) for measuring the surface state of a sample by scanning the surface of the sample with a probe have been proposed one after another. For example, a scanning atomic force microscope that uses atomic force as an interaction between a probe and a sample, a scanning magnetic force microscope that uses magnetic force as an interaction between a probe and a sample, a probe and a sample. Scanning ion-conducting microscope that uses ion conduction as an interaction between the probe and the sample, Scanning acoustic microscope that uses acoustic as interaction between the probe and the sample, Evanescent as the interaction between the probe and the sample For example, a scanning evanescent light microscope that uses light is used. Even when the principle of such a scanning probe microscope is used, high-density recording / reproducing can be performed as in the case of using the principle of the scanning tunneling microscope.

[Problems to be Solved by the Invention] However, in a recording / reproducing apparatus using the principle of the above-mentioned scanning probe microscope or applying the scanning probe microscope, a plurality of probe electrodes are used for recording and reproducing information. In this case, the surface formed by the probe tips of the plurality of probe electrodes (hereinafter, referred to as “probe tip surface”), the surface of the recording medium, and the scanning surface are aligned in total of three surfaces (the inclination of the recording medium). Correction) is required. Here, the scanning surface refers to the scanning surface generated by the relative movement of the plurality of probe electrodes and the recording medium.

The alignment between the scanning surface and the surface of the recording medium is
The probe electrode and the recording medium are moved relative to each other, and the amplitude of the signal component (the displacement amount of the probe electrode in the Z direction or the tunnel current variation amount) caused by the inclination of the recording medium detected at that time is set to zero or the minimum value. So that
This can be done by correcting the tilt of the recording medium using the tilt mechanism. However, although this surface alignment method is preferably used during low-speed scanning or as preparation before scanning, it has the following problems during high-speed scanning during recording / reproduction of large-capacity information.

During high-speed scanning, the movable part of the fine movement mechanism of the recording medium is driven at high speed, so that minute vibrations or surface wobbling occur in the movable part of the fine movement mechanism of the recording medium. for that reason,
A deviation from the parallel plane that was made at the time of low-speed scanning occurs, and a new plane alignment must be performed. However, in the above-mentioned face-to-face alignment using the feedback signal of the probe electrode, sufficient face-to-face alignment cannot be performed due to the limitation of the operating frequency bandwidth of the feedback control of the probe electrode.

A first object of the present invention is to provide a surface alignment method capable of precisely parallelizing the scanning surface and the surface of the recording medium even during high speed scanning.

B. Regarding Position Control Mechanism of the Present Invention and Information Processing Apparatus Having the Mechanism [Prior Art] In recent years, the use of memory materials has become the core of the electronics industry such as computers and related equipment, and video discs and digital audio discs. Therefore, the development of memory materials is extremely active. The required performance of the memory material depends on the application, but it is essential that the response speed of recording and reproduction is fast. Until now, semiconductor memories and magnetic memories made of semiconductors and magnetic materials were mainly used, but with the recent advances in laser technology, optical memories that use organic thin films such as organic dyes and photopolymers are inexpensive and cost-effective. A dense recording medium has appeared.

On the other hand, recently, a scanning tunneling microscope (STM) has been developed which can directly observe the electronic structure of surface atoms of a conductor (G. Binnig et al., Phys. Rev. Lett, 49, 57, 1
982), regardless of whether it is a single crystal or an amorphous material, it becomes possible to measure a real space image with high resolution, and it has the advantage that it can be observed with low power without damaging the sample with current. Since it operates in the atmosphere and can be used for various materials, it is expected to have a wide range of applications.

The scanning tunneling microscope utilizes that a tunnel current flows when a metal probe (probe electrode) and a conductive substance are brought to a distance of about 1 nm while a voltage is applied between them. is doing. This tunnel current is very sensitive because it responds exponentially to changes in distance between the two. By scanning the probe so as to keep the tunnel current constant, it is possible to read various kinds of information regarding all electron clouds in the real space. At this time, the resolution in the in-plane direction is about 0.1 nm.

Therefore, if the principle of the scanning tunneling microscope is applied, it is possible to sufficiently perform high density recording / reproducing on the atomic order (sub-nanometer). For example, in the information processing apparatus disclosed in Japanese Patent Laid-Open No. 61-80536, writing is performed by removing atomic particles adsorbed on the surface of the medium by an electron beam or the like, and this data is reproduced by a scanning tunneling microscope. ing. In addition, by using a material having a memory effect on the switching characteristics of voltage and current as a recording layer (for example, a thin film layer of an organic compound or a chalcogen compound having a conjugated π electron system), recording and reproduction are performed by a scanning tunneling microscope. A method of carrying out the method has been proposed (JP-A-63-161552 and JP-A-63-161553). According to this method, if the recording bit size is 10 nm, 1
It is possible to record and reproduce a large capacity of Tbit / cm.

As a control mechanism of the probe electrode, there is a cantilever type (Japanese Patent Laid-Open No. 62-281138), which has a length of 1 made of SiO ₂ on a silicon substrate.
It is possible to fabricate a plurality of cantilever-type mechanisms each having a size of about 00 μm, a width of 10 to 20 μm, and a thickness of about 0.5 μm, and write / read circuits are integrated on the same substrate.

However, when the recording medium is accessed using the multi-probe array head having a plurality of probe electrodes, it is necessary to dispose the probe head substrate and the recording medium substrate in parallel. The distance between these two substrates is usually set to 1 to 3 μm. Further, the variation amount is required to be ± 0.5 μm or less.
For example, when a probe electrode is formed on a cantilever having a length of 300 μm and the cantilever is displaced in the vertical direction of the substrate by electrostatic force or piezoelectric power, the maximum displacement amount is 3 to 10 μm. And
The tips of all probe electrodes are arranged on the same plane, and in order to maintain the same probe electrode-substrate distance, the distance between the probe head substrate and the recording medium substrate is within the movable range of the cantilever, and Each cantilever must be placed at a distance that can compensate for variations in warpage caused by manufacturing.

As a position detecting method for this arrangement control, S
A device using a TM probe or a capacitance electrode can be considered.

The position detecting method using the STM probe is
The distance between the two substrates is estimated by providing the M probe on the probe head substrate or the recording medium substrate and measuring the tunnel current caused by the tunnel effect caused by bringing the two substrates closer to each other. Further, the position detection method using a capacitance electrode, by detecting the capacitance formed by the electrode surface provided on the probe head substrate and the electrode surface provided on the recording medium substrate facing it, This is a method of measuring the distance between the substrates.

[Problems to be Solved by the Invention] However, the above-described position detecting method using the STM probe and position detecting method using the capacitance electrode have the following problems.

In the position detecting method using the STM probe, since the distance is measured by using the tunnel current, the accuracy is very high, but the distance at which the tunnel current is measured is about several nm at most. It is difficult to control the surface spacing at a distance larger than this distance.

Further, in the position detecting method using the electrostatic capacitance electrode, unlike the one using the tunnel current, several tens to several 1
A signal can be sensed from a distance of 00 μm, and an interval control and a tilt correction control can be performed even at a distance that is somewhat long, but the absolute position accuracy is not depending on the state of each surface and the environment. For example, an adhered matter or an adsorbed matter on the surface of the electrode substrate affects the capacitance between the two electrodes. Therefore, when performing the interval control or the tilt correction control depending on the capacity, the detected capacity may vary depending on each lot or due to the difference in the execution environment, so that both substrates often come into contact or collision during operation. .

A second object of the present invention is to have a position control mechanism which can obtain high accuracy even when the probe head substrate and the recording medium substrate are close to each other and has a wide position detection range, and the mechanism. To provide an information processing device.

[0022]

A surface alignment method of the present invention comprises a recording medium for recording information, and a predetermined voltage applied to the recording medium which is provided so as to face the recording medium. It has a plurality of probe electrodes, a first surface aligning unit having a first tilt mechanism for correcting the tilts of the plurality of probe electrodes, and a second tilt mechanism for correcting the tilt of the recording medium. It includes a second surface aligning unit and a relative moving unit for relatively moving the recording medium and the plurality of probe electrodes, and depends on a distance between the plurality of probe electrodes and the recording medium. A scanning surface generated by relative movement of the plurality of probe electrodes and the recording medium, which is used in an information processing device that relatively scans the plurality of probe electrodes with respect to the recording medium while detecting an interaction; In a surface alignment method for performing surface alignment with the surface of a recording medium, when the relative movement means scans the recording medium with respect to the plurality of probe electrodes at a low speed, it is obtained by detecting the interaction. A rough surface between the scanning surface and the surface of the recording medium is formed by using at least one of the first tilt mechanism and the second tilt mechanism according to a surface state of the recording medium or a signal corresponding to recording information. When performing the alignment and scanning the recording medium with respect to the plurality of probe electrodes at a high speed by the relative moving means, the nth natural frequency (n = n) of the relative moving means obtained by detecting the interaction is obtained. 0, 1,
2 ...), using at least one of the first tilt mechanism and the second tilt mechanism so that the amplitude of the signal component corresponding to It is characterized by performing precise face-to-face contact with the surface.

Here, of the signal components of the signal corresponding to the surface condition of the recording medium or the recording information, the amplitude of the signal component corresponding to the scanning frequency of the relative moving means is set to zero or the minimum value. Rough surface alignment between the scanning surface and the surface of the recording medium may be performed.

The position control mechanism of the present invention comprises a first substrate,
A first flat plate electrode arranged on the first substrate, a second substrate provided opposite to the first substrate, and a second flat plate arranged on the second substrate. An electrode and the first
Of the capacitance value formed by the first flat plate electrode and the second flat plate electrode, including an AC power supply for applying a predetermined AC voltage between the flat plate electrode and the second flat plate electrode. A position control mechanism that measures the change in the potential difference between the first plate electrode and the second plate electrode from the change and controls the distance between the first substrate and the second substrate. And further includes an electrically grounded microprojection projectingly provided on the surface of the first plate electrode, a part of the microprojection electrically connecting to a part of the second plate electrode. The distance between the first substrate and the second substrate is adjusted to the distance at which a voltage drop occurs between the first plate electrode and the second plate electrode when the first plate electrode and the second plate electrode are brought into contact with each other. And

Here, the voltage between the first plate electrode and the second plate electrode, which is generated when a part of the minute convex portion electrically contacts a part of the second plate electrode. From the drop, the distance between the first substrate and the second substrate is determined, and the potential difference between the first plate electrode and the second plate electrode is corrected according to the determined distance. You may further include the correction means to do.

In the information processing apparatus of the present invention, the probe, the recording medium provided so as to face the probe, the probe and the recording medium are brought close to each other, and the probe and the recording medium are provided. A scanning mechanism that relatively scans the recording medium, and a recording unit that records information in the minute region by causing a physical change in the minute region of the recording medium by the probe during scanning by the scanning mechanism. Detecting means for detecting a minute signal obtained from interaction between the probe and the recording medium during scanning by the scanning mechanism, and reproducing information recorded on the recording medium from an output signal of the detecting means. In the information processing apparatus including the reproducing means, the substrate further includes a substrate on which the plurality of probes are arranged, and a position control mechanism of the present invention for controlling a distance between the substrate and the recording medium. And

[0027]

In the surface aligning method of the present invention, the surface alignment of the scanning surface and the surface of the recording medium is roughly performed at low speed according to the surface state of the recording medium or a signal corresponding to the recording information, and at the high speed. At the time of scanning, it is precisely performed from the signal component corresponding to the parasitic vibration of the relative movement mechanism. Accordingly, it is possible to prevent contact between the plurality of probe electrodes and the recording medium during high-speed scanning. More specifically, by using the above-described surface alignment during low-speed scanning and surface alignment during high-speed scanning together, the distance between the plurality of probe electrodes and the recording medium during high-speed scanning can be adjusted with sub-micron accuracy. Can be controlled by.

In the position control mechanism of the present invention, a portion between the first flat plate electrode and the second flat plate electrode, which is generated when a part of the minute convex portion electrically contacts a part of the second flat plate electrode, is provided. By detecting the voltage drop, the first in capacitance detection
The absolute distance between the substrate and the second substrate can be measured with high accuracy. Further, since the potential difference between the first plate electrode and the second plate electrode can be corrected by using the interval between the minute convex portion and the second plate electrode as a reference interval, the detection system is based on capacitance detection. Therefore, highly accurate interval control can be performed.

Since the information processing apparatus of the present invention is equipped with the position control mechanism of the present invention, it is possible to record information on a recording medium and reproduce recorded information from the recording medium with high accuracy.

[0030]

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

A. Regarding the Surface Aligning Method of the Present Invention FIG. 1 is a schematic block diagram showing the structure of a recording / reproducing apparatus capable of realizing the first embodiment of the surface aligning method of the present invention.

The recording / reproducing apparatus 10 includes a plurality of probe electrodes 11 formed by a micromechanics technique, a probe electrode attachment 12 for setting the plurality of probe electrodes 11 on the first tilt mechanism 13, and a plurality of probe electrodes. A first tilt mechanism 13 for correcting the tilt of the probe 11 and a Z-direction fine movement / coarse movement mechanism 14 for finely moving and coarsely moving the plurality of probe electrodes 11 in the Z-axis direction in the drawing are included.

The recording / reproducing apparatus 10 also includes a second tilt mechanism 21 for correcting the inclination of the recording medium 1 and XY directions for finely and roughly moving the recording medium 1 in the X-axis and Y-axis directions in the figure. A fine movement / coarse movement mechanism 22 is further included. Here, the recording medium 1 includes a mica substrate ₁₁ and a thickness of 1000.
Of Au Å the base electrode 1 ₂ formed by epitaxially growing on the mica substrate 1 _1, made of an organic recording layer 1 ₃ which is laminated on the base electrode 1 _2. The organic recording layer 1 ₃
Is L of squarylium-bis-6-octylazulene
It consists of B film (6 layers).

Further, the recording / reproducing apparatus 10 has an interface 31, a control circuit 32, and a writing / reading circuit 33.
A bias circuit 34, a tunnel current detector 35,
Position detection circuit 36, positioning circuit 37, servo circuit 38, Z direction drive circuit 39, and XY direction drive circuit 40.
And a demultiplexer 41 and a tilt mechanism drive circuit 42.

Here, the interface 31 is for performing input / output of write / read information I _WR , output of status, input of control signal and output of address signal. The control circuit 32 is connected to the interface 31 and is for centralized control of the interaction between the blocks of the recording / reproducing apparatus 10. The write / read circuit 33 is connected to the interface 31 and is for writing and reading the write / read information I _WR according to an instruction from the control circuit 32. The bias circuit 34 is for applying a write pulse voltage and a read voltage between the plurality of probe electrodes 11 and the recording medium 1 in response to a command from the write / read circuit 33. The tunnel current detector 35 is for detecting a current flowing between the plurality of probe electrodes 11 and the recording medium 1 during recording and reproduction. The position detection circuit 36 includes a plurality of probe electrodes 11 and the recording medium 1.
It is for detecting the position of. Positioning circuit 37
Is a tunnel current detector 35 according to an instruction from the control circuit 32.
And for determining the positions of the plurality of probe electrodes 11 and the recording medium 1 based on signals from the position detection circuit 36. The servo circuit 38 serves to servo the positions of the plurality of probe electrodes 11 and the recording medium 1 based on the servo signal from the positioning circuit 37. Z
The direction drive circuit 39 is for driving the Z direction fine movement / coarse movement mechanism 14 in accordance with a signal from the servo circuit 38. The XY-direction drive circuit 40 is for driving the XY-direction fine movement / coarse movement mechanism 22 in accordance with a signal from the servo circuit 38. The duplexer 41 detects the position detection circuit 36 based on the height component based on the unevenness of the surface of the recording medium 1 and the change of the electronic state and the component caused by the inclination of the surface of the recording medium 1.
It is for separating the signal obtained in. The tilt mechanism drive circuit 42 drives each of the first tilt mechanism 13 and the second tilt mechanism 21 to adjust the amplitude of the signal component from the demultiplexer 41 to zero or a value as small as possible. belongs to.

Although only one control circuit 32, one write / read circuit 33, one bias circuit 34, and one tunnel current detector 35 are shown in FIG. 1, in reality, a plurality of probe electrodes 11 are provided. The number of probe electrodes is provided.

Next, the structure of the plurality of probe electrodes 11 will be described with reference to FIGS. 2 to 4, respectively.

The plurality of probe electrodes 11 are formed on the surface of the multi-probe substrate 105 by using a well-known micromechanics technique. Each probe electrode 100 of the plurality of probe electrodes 11 is, as shown in FIG.
0 and the probe 120 provided at the tip of the cantilever 110
And the extraction electrode 121 (see FIG. 3).

Here, as shown in FIG. 3, the cantilever 110 is composed of two upper electrodes 111 and 114, one middle electrode 112, and two middle electrodes 112.
Lower electrodes 113 and 115, a first piezoelectric thin film 116 formed between the upper electrodes 111 and 114 and the middle electrode 112, and the middle electrode 112.
Second piezoelectric thin film formed between the lower electrode and the lower electrodes 113 and 115
It consists of 117 and. Upper electrodes 111, 114 and lower electrodes 113, 115
Are each divided into two in the width direction of the cantilever 110, and the middle electrodes 112 are provided on one surface without being divided. In addition, the upper electrodes 111 and 114 and the first piezoelectric thin film 11
6, the middle electrode 112, the second piezoelectric thin film 117, and the lower electrodes 113, 1
The reference numeral 15 is arranged in layers so that the cantilever 110 is displaced in the X-axis and Z-axis directions in the figure by the balance of expansion and contraction of the first and second piezoelectric thin films 116 and 117. The left end portion of the lower electrode 113 in FIG. 2 is the multi-probe substrate 105.
Formed on. The probe 120 is for detecting a tunnel current and applying a write pulse voltage and a read voltage to the recording medium 1. In addition, the extraction electrode 121, as shown in FIG.
The piezoelectric thin film 116 is provided between the two upper electrodes 111 and 114 on the upper surface in the drawing, and the probe 120 is provided on the upper surface of the end portion.

As shown in FIG. 4, the plurality of probe electrodes 11 are two-dimensionally arranged with a total of 200 probe electrodes 100, 10 in the X-axis direction and 20 in the Y-axis direction. It has become. Here, each probe electrode 100 is formed on the surface of the multi-probe substrate 105 in a state where the probe tips are lined up neatly without any variation. In each probe electrode 100, a voltage applying wire for applying a pulse voltage and a read voltage for current detection wiring and writing for detecting a tunnel current from the probe 120 to the organic recording layer 1 ₃ is made There is. In addition,
The current detection wiring is connected to each tunnel current detector 35, and the voltage application wiring is connected to each bias circuit 34.

Next, the basic principle of the surface matching method of the present invention will be described. First, for example, an nth-order natural frequency (n
= 0, 1 ...) so that the amplitude of the signal component corresponding to
Regarding the case where the scanning surface and the surface of the recording medium 1 are aligned with each other with reference numerals 3 and 21, a scanning tunneling microscope having one probe (probe electrode) will be taken as an example, and respectively refer to FIGS. explain.

As shown in FIG. 5, the XY direction fine movement mechanism 210 is provided.
Consider a case where a sample (recording medium) 201 is placed on the sample, and a probe (probe electrode) 211 for observing the surface of the sample 201 is arranged so as to face the sample 201. Although not shown in FIG. 5, the probe 211 and the sample 20
A bias circuit and a tunnel current detector are connected between 1 and each.

FIG. 6 is an enlarged view of the surface of the sample 201 and the tip of the probe 211. In order to simplify the explanation, the sample 201 is assumed to be driven by the XY direction fine movement mechanism 210 only in the left and right uniaxial directions. Here the probe
211 is stationary, and the surface of the sample 201 is inclined so that the right side in the drawing becomes lower.

FIG. 7 is a graph showing an example of the sample drive signal S _D applied to the XY direction fine movement mechanism 210 and the tunnel current I _T detected by the probe 211 at that time. Consider a case where the sample drive signal S _D is a triangular wave as shown in FIG. 7 and the XY direction fine movement mechanism 210 is reciprocally scanned in the left and right directions in FIG. 6 at high speed. At this time, X at low speed
Parasitic vibration corresponding to the natural frequency of the movable portion, which does not occur when the Y-direction fine movement mechanism 210 is driven, is generated at the folded portion (top of the triangular wave) of the sample drive signal S _D.

There is no problem when the scanning surface and the surface of the recording medium 201 are parallel to each other, but when the scanning surface and the surface of the recording medium 201 are slightly inclined, the parasitic vibration is detected. It becomes coupled with the current I _T. This is because, as shown in FIG. 6, when the sample 201 is moved from the right to the left in the figure and then to the right, the sample drive signal S _D is scanned from the left to the right in the figure.
This is because the point A and the tip of the probe 211 come close to and away from each other due to parasitic vibration occurring in the lateral direction in the drawing. As a result, the tunneling current I _T is constant when the the surface and the scanning surface of the sample 201 are parallel, the tunneling current I _T
Since the flow path of the sample driving signal changes, the vibration is generated at the folded portion of the sample drive signal S _D as shown in FIG. The cycle of this vibration corresponds to the natural frequency of the movable part, and its amplitude corresponds to the magnitude of the damping value of the XY direction fine movement mechanism 210.

Since the oscillation of the tunnel current I _T is sensitive to a slight inclination between the surface of the sample 201 and the scanning surface (due to the very good sensitivity of the tunnel current I _T ), the amplitude of this signal component. By zeroing or minimizing, the surface of the sample 201 and the scanning surface can be precisely aligned.

Next, the surface alignment method in the recording / reproducing apparatus 10 shown in FIG. 1 will be described in detail.

The recording / reproducing apparatus 10 has a structure in which a plurality of probe electrodes 11 are fixed in the X-axis and Y-axis directions in the figure, and the recording medium 1 is finely moved in the X-axis and Y-axis directions in the figure. When observing (reproducing operation) the surface state of the recording medium 1 using such a recording / reproducing apparatus 10, (a) the height of each probe electrode is adjusted so that the tunnel current detected by each probe electrode becomes constant. Of the height of each probe electrode (hereinafter referred to as "current constant mode"), and (b) the height of each probe electrode is fixed to a constant value, and the tunnel is used during scanning. Method for measuring the amount of change in current (hereinafter referred to as "constant height mode")
There is.

The surface matching method of this embodiment uses the constant current mode as the rough surface matching means.

Using the Z-direction fine movement / coarse movement mechanism 14, a plurality of probe electrodes 1 are moved up to a distance at which a tunnel current can be detected.
One specific probe electrode is brought close to the recording medium 1. At this time, the distance between the recording medium 1 and the probe electrode is 1
A voltage of V is applied by the bias circuit 34, and feedback control is performed so that the tunnel current becomes 10 nA. The specific probe electrode may be an arbitrary probe electrode of the plurality of probe electrodes 11, or a probe electrode in which a tunnel current is first detected when the plurality of probe electrodes 11 are brought close to the recording medium 1, The probe electrode may be intentionally displaced in the direction of the recording medium 1 so that the tunnel current is first detected.

Considering the case where the recording medium 1 is reciprocally scanned in one axis direction (for example, the X axis direction in the drawing) with a specific probe electrode pulled in the tunnel region, the fine and coarse movement mechanism 22 is supplied to the XY direction. The scanning mechanism drive signal S
As shown in FIG. 8, it is a triangular wave. At this time, the amount of height change of the probe electrode (displacement D _{Z in the} probe electrode Z direction) when the surface of the recording medium 1 and the scanning surface are inclined is as shown in FIG.
Is shown by the solid line. That is, the frequency of the signal component derived from the inclination of the recording medium 1 is synchronized with the frequency of the scanning mechanism drive signal S. However, depending on the inclination direction of the recording medium 1, the phase may be 180 degrees as shown by the broken line in FIG.
There may be a deviation.

With the duplexer 41, the displacement D in the Z direction of the probe electrode
_The signal indicating _Z is divided into a plurality of frequency bands including an arbitrary frequency region. A frequency derived from the tilt of the recording medium 1 (frequency of the scanning mechanism drive signal S) is selected from the plurality of divided frequency bands, and the second tilt mechanism is selected so that the amplitude of the selected frequency is as zero as possible. 21 is used to correct the tilt of the recording medium 1. Specifically, the inclination of the recording medium 1 is corrected by applying a predetermined voltage to the piezoelectric element forming the second tilt mechanism 21.

The first scan may be performed in an appropriate range according to the size of the information processing area. 2μ in one experimental result
When the recording medium 1 is tilted at a distance of m, a tilt of the recording medium 1 of about 10 nm occurs, and the tilt of the recording medium 1 is tilted by applying a voltage of 10 V to the piezoelectric element forming the second tilt mechanism 21. Was able to be corrected. The scanning and the second tilt mechanism 21 for correcting the tilt of the recording medium 1 are performed.
The feedback to may be performed several times as needed.

The above operation is performed in another direction (for example, Y in the figure).
In terms of the axial direction as well, the surface of the recording medium 1 and the scanning surface are parallel.

As a result, rough surface alignment between the scanning surface and the surface of the recording medium 1 can be performed. However, in actuality, in addition to this, the surface of the recording medium 1 and the tip surface of the probe must be aligned. The surface of the recording medium 1 (or the scanning surface) and the probe tip surface are aligned by detecting the probe electrode not used for the alignment of the scanning surface and the surface of the recording medium 1 with the probe electrode used for the alignment. Recording medium 1 so that the tunnel current value is the same.
It may be displaced in the direction of. As a result, rough surface alignment of the three surfaces (that is, the probe tip surface, the scanning surface, and the surface of the recording medium 1) is completed.

This degree of face-to-face alignment may be used during low-speed scanning, but for high-speed scanning (for example, 6
(00 Hz), more precise surface alignment must be performed.

Next, a surface alignment method during high speed scanning will be described with reference to FIG.

When the recording medium 1 is scanned in the X-axis direction shown in FIG. 1 at a predetermined scanning frequency (for example, 600 Hz), as described above, the natural vibration of the movable portion of the XY direction fine / coarse movement mechanism 22. Parasitic vibration corresponding to the number occurs. As a result of this vibration, as shown in FIG. 9, the tunnel current I _T detected by the probe electrode oscillates in synchronization with the scanning mechanism drive signal S of the XY direction fine movement / coarse movement mechanism 22. For example, when a triangular wave of 600 Hz is used as the scanning mechanism drive signal S, the tunnel current I _T is vibrated by a parasitic vibration with a maximum amplitude of 1 mA (tunnel current) at 1200 Hz intervals.

Using the branching filter 41, the signal indicating the tunnel current I _T is divided into a plurality of frequency bands including arbitrary frequency regions. A frequency (an XY-direction fine movement / coarse movement mechanism 2) derived from the inclination of the recording medium 1 is selected from the plurality of divided frequency bands.
2 natural frequency of the movable part), and the tilt of the recording medium 1 is finely corrected by using the second tilt mechanism 21 so that the amplitude of the selected frequency becomes zero as much as possible. Specifically, the inclination of the recording medium 1 is finely corrected by applying a predetermined voltage to the piezoelectric element forming the second tilt mechanism 21.

According to one experimental result, the natural frequency of the fine movement / coarse movement mechanism 22 in the X-axis direction in the figure is 5.6 kHz, and the frequency derived from the inclination of the recording medium 1 is 5.6 kHz.
When the inclination of the recording medium 1 was corrected by using Hz, the inclination of the recording medium 1 could be finely corrected by applying 100 mV to the piezoelectric element forming the second tilt mechanism 21. The feedback to the second tilt mechanism 21 for correcting the tilt of the recording medium 1 during high speed scanning is
You may perform it several times as needed.

If the above operation is also performed in the Y-axis direction shown in FIG. 1, the surface of the recording medium 1 and the scanning surface during high speed scanning become parallel.

It is necessary to demultiplex the signal (information reproduction signal) corresponding to the surface condition of the recording medium 1 into an arbitrary frequency and examine the amplitude of the demultiplexed signal component. A lock-in amplifier may be used for the operation.
That is, the demultiplexer 41 may be a lock-in amplifier. In the lock-in amplifier, the amplitude of the signal component of an arbitrary frequency in the input signal (here, the signal corresponding to the surface state of the recording medium 1) can be checked, and the reference signal is input to determine the frequency of the reference signal. You can check the amplitude of the input component with. Therefore, if the scanning signal or the natural frequency of the probe electrode is used as the reference signal,
The degree of inclination of the recording medium 1 can be known more easily.

The surface alignment method of the present embodiment makes it possible to more easily match the surface deviation due to the vibration of the relative movement mechanism, which has conventionally been generated during high-speed scanning, and the distance between the probe tip and the recording medium 1 during high-speed scanning. It becomes possible to control the distance of with sub-micron accuracy.

The first embodiment of the surface aligning method of the present invention has been described above by taking the recording / reproducing apparatus to which the scanning tunneling microscope is applied as an example. However, the surface aligning method of this embodiment is simply a tunnel at each point. Not only when measuring current,
It is needless to say that it is also effective for a recording / reproducing apparatus that uses scanning tunneling spectroscopy (STS) that measures the rate of change of tunnel current with respect to bias voltage at each point.
Further, the present invention is also applicable to a recording / reproducing apparatus using another scanning probe microscope or the like whose drive mechanism between the probe and the sample is similar to that of the scanning tunnel microscope.

(A) A scanning atomic force microscope (AFM) which measures the atomic force acting between the probe and the sample and obtains the structure of the surface of the sample by feeding back so as to keep the magnitude constant. (B) Replacing the probe in a scanning atomic force microscope (AFM) with a ferromagnetic substance such as Fe or Ni or a probe made of other material and coating the probe locally on the sample. Scanning Magnetic Force Microscope (MFM) for measuring magnetic force (c) Scanning Ion Conductance Microscope (SICM) for measuring sample surface structure in an electrolyte solution from changes in ionic conductivity using a micropipette electrode as a probe (d) Use the change in the amplitude and phase of the ultrasonic wave that is ultrasonically vibrated by the needle and reflected by the surface of the sample and returned to the probe, or change the atomic force acting on the surface of the sample and the ultrasonically vibrated probe. To strength Flip by measuring the acoustic wave generated in the sample to measure the surface structure of the sample scanning acoustic microscope (stum
(STAM) (e) An optical probe having a pinhole with a diameter smaller than the wavelength of light is used, and the evanescent light generated on the surface of the sample when the sample is irradiated with an external light source is detected by the optical probe to detect the sample. Scanning near-field optical microscope (NS
OM).

Next, a second embodiment of the surface aligning method of the present invention, which uses the constant height mode as the rough surface aligning method, will be described by taking the case of the recording / reproducing apparatus 10 shown in FIG. 1 as an example.

Using the Z direction fine movement / coarse movement mechanism 14, specific probe electrodes of the plurality of probe electrodes 11 are brought close to the recording medium 1 until the tunnel current I _T can be detected. At this time, the bias circuit 34 applies a voltage of 1 V between the recording medium 1 and the probe electrode, and performs feedback control so that the tunnel current I _T becomes 10 nA. The specific probe electrode may be any probe electrode of the plurality of probe electrodes 11. That is, a probe electrode in which the tunnel current I _T is first detected when the plurality of probe electrodes 11 approach the recording medium 1 may be used, and the recording medium is intentionally detected so that the tunnel current I _T is first detected. The probe electrode may be displaced in the direction of 1.

The recording medium 1 is reciprocally scanned in the uniaxial direction (for example, the X-axis direction in the drawing) while the specific probe electrode is pulled into the tunnel region. When the constant height mode is used, if the tilt of the recording medium 1 is large to some extent, the probe electrode is too far from the recording medium 1 and the tunnel current I _T can no longer be detected, or
Either the probe electrode contacts the recording medium 1. Normally, in order to avoid such a situation, even in the constant height mode, feedback is provided to the servo circuit 38 so that the value of the detected tunnel current I _T falls within a certain range, and the probe is used. The electrode height is often changed slowly.

Also in this case, as shown in FIG. 10, the scanning mechanism drive signal S of the XY direction fine movement / coarse movement mechanism 22 is inputted.
A signal component derived from the tilt of the recording medium 1 synchronized with the pulse current is detected in the tunnel current I _T. The displacement signal of the tunnel current I _T of the probe electrode is divided into a plurality of frequency bands including an arbitrary frequency region by using the demultiplexer 41. A frequency derived from the inclination of the recording medium 1 (frequency of the scanning mechanism drive signal S) is selected from among them, and the second tilt mechanism 21 is used to make the amplitude of the selected frequency as zero as possible. Correct the inclination of. Specifically, the inclination of the recording medium 1 is corrected by applying a predetermined voltage to the piezoelectric element forming the second tilt mechanism 21.

The first scan may be performed in an appropriate range according to the size of the information processing area. 2μ in one experimental result
When the recording medium 1 is tilted at a distance of m, the tilt of the recording medium 1 is about 10 nm, and the tilt of the recording medium 1 is changed by applying a voltage of 10 V to the piezoelectric element forming the second tilt mechanism 21. I was able to correct it. The recording medium 1
The scanning for the tilt correction and the feedback to the second tilt mechanism 21 may be performed several times as necessary.

If the above operation is performed also in other directions (for example, the Y-axis direction shown in FIG. 1), the surface of the recording medium 1 and the scanning surface become parallel.

As a result, rough surface alignment between the scanning surface and the surface of the recording medium 1 could be performed. However, in addition to this, in actuality, the surface (or scanning surface) of the recording medium 1 and the probe tip surface are You must also make a face-to-face meeting. Recording medium 1
The surface of the probe (or the scanning surface) is aligned with the tip surface of the probe by the probe electrode not used for the surface alignment of the scanning surface and the surface of the recording medium 1 being detected by the probe electrode used for the surface alignment. It may be displaced in the direction of the recording medium 1 so that it becomes equal to the value of the current I _T.

Thus, rough surface alignment of the three surfaces (that is, the probe tip surface, the scanning surface, and the surface of the recording medium 1) is completed. This degree of face-to-face alignment may be used during low-speed scanning, but for the reasons described above, more precise face-alignment must be performed during high-speed scanning (for example, 600 Hz).

Next, the surface alignment at the time of high speed scanning will be described in detail.

When scanning is performed at a predetermined scanning frequency (for example, 600 Hz) in the X-axis direction shown in FIG. 1, as described above,
Parasitic vibration corresponding to the natural frequency of the movable part of the XY direction fine movement / coarse movement mechanism 22 is generated. Due to this vibration, as shown in FIG. 9, the tunnel current I _T detected by the probe electrode is detected.
Vibrates in synchronization with the scanning mechanism drive signal S of the XY direction fine movement / coarse movement mechanism 22. According to one experimental result, when a 600 Hz triangular wave was used as the scanning mechanism drive signal S, the tunnel current I _T generated vibrations due to parasitic vibration with a maximum amplitude of 1 mA at 1200 Hz intervals.

Using the duplexer 41, the signal indicating the tunnel current I _T detected by this probe electrode is divided into a plurality of frequency bands including an arbitrary frequency range. A frequency (natural frequency of the movable portion of the XY direction fine movement / coarse movement mechanism 22) derived from the inclination of the recording medium 1 is selected from among them, and the second frequency is set so that the amplitude of the selected frequency becomes zero as much as possible. The tilt of the recording medium 1 is finely corrected using the tilt mechanism 21. Specifically, the inclination of the recording medium 1 was finely corrected by applying a predetermined voltage to the piezoelectric element forming the second tilt mechanism 21. According to the result of one experiment, slight movement in XY direction
The natural frequency of the coarse movement mechanism 22 in the X-axis direction in the figure is 5.6 kHz.
In the case of z, the inclination of the recording medium 1 is corrected by using 5.6 kHz as the frequency derived from the inclination of the recording medium 1, and 100 mV is applied to the piezoelectric element constituting the second tilt mechanism 21. As a result, the inclination of the recording medium 1 could be finely corrected. The feedback to the second tilt mechanism 21 for correcting the tilt of the recording medium during high-speed scanning may be performed several times as necessary.

If the above operation is also performed in the Y-axis direction shown in FIG. 1, the surface of the recording medium 1 and the scanning surface during high speed scanning become parallel.

It is necessary to demultiplex the signal (information reproduction signal) corresponding to the surface condition of the recording medium 1 into an arbitrary frequency and examine the amplitude of the demultiplexed signal component. A lock-in amplifier may be used for the operation.
That is, the demultiplexer 41 may be a lock-in amplifier. In the lock-in amplifier, the amplitude of the signal component of an arbitrary frequency in the input signal (here, the signal corresponding to the surface state of the recording medium 1) can be checked, and the reference signal is input to determine the frequency of the reference signal. You can check the amplitude of the input component with. Therefore, if the scanning signal or the natural frequency of the probe electrode is used as the reference signal,
The degree of inclination of the recording medium 1 can be known more easily.

The surface alignment method of the present embodiment makes it possible to more easily align the surface displacement due to the vibration of the relative movement mechanism, which has conventionally been generated during high-speed scanning, and the distance between the probe tip and the recording medium 1 during high-speed scanning. It becomes possible to control the distance of with sub-micron accuracy.

Although the second embodiment of the surface aligning method of the present invention has been described above by taking the recording / reproducing apparatus to which the scanning tunneling microscope is applied as an example, the surface aligning method of the present embodiment is not limited to the other scanning described below. It can also be applied to a recording / reproducing apparatus using a probe probe microscope or the like.

(A) Scanning tunneling spectroscopy (STS) (b) Scanning atomic force microscope (AFM) (c) Scanning magnetic force microscope (MFM) (d) Scanning ion conductance microscope (SICM) (e) Scanning Acoustic Microscope (STUM or STAM) (f) Scanning Near-Field Optical Microscope (NSOM).

B. Regarding Position Control Mechanism of the Present Invention and Information Processing Apparatus Having the Mechanism FIG. 11 is a diagram for explaining the operation of one embodiment of the position control mechanism of the present invention.

The position control mechanism 1000 includes an AC power supply 1110, a bias resistor 1111, an upper electrode 1112, a lower electrode 1113, and
Minute convex portion 1114, read resistor 1115, and position detection circuit 1116
A position control circuit 1117, a drive mechanism 1118, and an upper substrate 1119.
And a lower substrate 1120.

Here, the AC power supply 1110 supplies a predetermined AC voltage (bias voltage) to the upper electrode via the bias resistor 1111.
It is for applying to 1112. The upper electrode 1112 is provided on the lower side of the upper substrate 1119 in the figure, and is moved in the vertical direction in the figure by a drive mechanism 1118 provided on the upper side of the upper substrate 1119 in the figure. The lower electrode 1113 is provided on the upper side of the lower substrate 1120 in the figure in three divisions. Of the three divided lower electrodes 1113, the right and left lower electrodes 1113 in the figure are electrically grounded via a read resistor 1115, respectively.
The remaining lower electrode 1113 at the center of the drawing is electrically grounded. In addition, the minute convex portion 1114 has a lower electrode 1113 at the center of the drawing.
Is provided on the upper side of the figure. The connection point between the lower electrode 1113 and the read resistor 1115 is connected to the position detection circuit 1116. The output signal of the position detection circuit 1116 is input to the position control circuit 1117, and the output signal of the position control circuit 1117 is input to the drive mechanism 1118.

The value of the electrostatic capacitance formed between the upper electrode 1112 and the lower electrode 1113 (hereinafter referred to as "electrostatic capacitance C") is shown below using the distance d between the two electrodes. It is defined by the equation (1).

C = ε · S / d (1) ε: Permittivity of air S: Electrode area Therefore, the capacitance C and the distance d have a one-to-one correspondence.

When the capacitance C is small, the read resistance 11
No current flows through 15, but as the capacitance C increases, a current flows through the read resistor 1115 and the position detection circuit 1116
A potential is generated at the input terminal of. The position detection circuit 1116 measures the potential with high accuracy by synchronous detection or the like, and estimates the distance d between the upper electrode 1112 and the lower electrode 1113 from the measured value. The estimated distance d is the position detection circuit 11
16 is sent to the position control circuit 1117. Position control circuit 1117
Then, in order to control the distance d according to the reference value,
The correction amount is calculated. The calculated correction amount is the position control circuit
By giving the driving mechanism 1118 from 1117, the distance d between the upper electrode 1112 and the lower electrode 1113 can be changed. This controls the distance d between the upper electrode 1112 and the lower electrode 1113 to a constant value. It should be noted that the distance detection range of such a system is from several 100 μm to several μm, and it is sensitive from a relatively long distance.

However, the detection of the distance d based on the above-described change of the electrostatic capacitance C greatly changes its sensitivity depending on the surrounding environment (for example, light, temperature, atmosphere or the state of the electrode surface (adsorption, dirt, etc.)). Since it is often the case, it is difficult to determine an accurate value of the distance with the configuration of only such a system. Therefore, in the position control mechanism 1000, the reference of the absolute distance is made by providing the minute convex portion 1114 having a known height. That is, the upper electrode 11
The distance d between the lower electrode 1113 and the lower electrode 1113 approaches the height of the minute convex portion 1114, so that the tip of the minute convex portion 1114 and the upper electrode
Makes electrical contact with 1112. When the contact resistance at the time of this electrical contact is about the same as the bias resistance 1111, the potential of the upper electrode 1112 drops. As a result, the potential (hereinafter, referred to as “detection voltage value”) generated at the input terminal of the position detection circuit 1116 also drops, so that by measuring the drop in the detection voltage value, highly accurate positioning is possible. Note that electrical contact refers to a state in which a current flows when two conductors having different potentials come close to each other, which may be due to a tunnel effect or physical contact.

In FIG. 12, the bias voltage value is 5 V,
Bias voltage frequency is 10 kHz, bias resistor 1111
Resistance value of 100 MΩ, read resistance 1115 resistance value of 10
An example of the detected voltage value when 0 MΩ and the height of the minute convex portion 1114 is 1 μm is shown. The horizontal axis of FIG. 12 represents the distance between the upper electrode 1112 and the tip of the minute convex portion 1114 (logarithmic scale). From this figure, when the distance between the upper electrode 1112 and the tip of the minute convex portion 1114 becomes smaller than 2 nm, the minute convex portion 1114
It can be seen that a tunnel phenomenon occurs between the upper electrode 1112 and the upper electrode 1112, and a current flows between them, and as a result, the applied voltage between the upper electrode 1112 and the lower electrode 1113 starts to drop, and the detected voltage value drops. .

Therefore, for example, by controlling the distance to the position where the detected voltage value starts to drop, the distance between the tip of the minute convex portion 1114 and the upper electrode 1112 can be controlled to 2 nm with high accuracy. . At this time, the upper substrate 1119 and the lower substrate
The distance to 1120 is 1.002 μm by adding the height 1 μm of the minute convex portion 1114. Further, the output signal at a distance of 2 nm or more is considered to be due to the measurement of only the capacitance C, but from FIG. 12, the position detection signal by the capacitance C is almost changed when the distance is around 10 nm or less. You know that you haven't. At this time, the alignment accuracy based on only the capacitance C was about 0.1 μm or less at most, even when considering the detection sensitivity and the noise component.

FIG. 13 is a schematic diagram showing an embodiment of the position control mechanism of the present invention.

The position control mechanism 2000 includes a multi-probe head substrate 2010 and a multi-probe head substrate support 2020.
And three support rods 2030 (only two support rods 2030 are shown)
And three piezo elements 2040 (see FIG. 14) and three D
C servo motor 2050 (only two DC servo motors 2050 are shown), tension spring 2060, Z direction drive mechanism 2070,
A support 2080, a recording medium substrate 2100, a recording medium substrate support 2110, and an XY scanning drive mechanism 2120 are included.

As will be described in detail later, the multi-probe head substrate 2010 is provided with a plurality of probe units each having a bimorph cantilever manufactured by a semiconductor process and three position detecting electrodes 2011 (see FIG. 14). Has been done. The multi-probe head substrate 2010 is fixed to the multi-probe head substrate support 2020. The multi-probe head substrate support 2020 has three support bars 20.
Supported by 30. The supporting point by the supporting rod 2030 is located on the multi-probe head substrate 2010 at a position corresponding to the electrode 2011 used for tilt correction. The multi-probe head substrate 2010 is supported at these three supporting points and the tension force by the tension spring 2060. By this, the inclination correction of the multi-probe head substrate 2010 and the approaching operation of the multi-probe head substrate 2010 and the recording medium substrate 2100 are performed.

Each of the three support rods 2030 is fixed to a piezo element 2040 composed of a laminated piezoelectric material. Each of the three piezo elements 2040 is supported by a DC servo motor 2050. Three DC servo motors 2050
Is fixed to the Z-direction drive control mechanism 2070. The approach operation between the multi-probe head substrate 2010 and the recording medium substrate 2100 is performed by three piezo elements 2040 and three DC servo motors.
Made by 2050. The Z-direction drive control mechanism 2070 controls these drive mechanisms. Driving accuracy is D
C servo motor 2050 0.1-1 μm, piezo element 2040
Is 0.1 nm. The whole of these mechanisms is supported by the support base 2080.
It is fixed to. FIG. 14 is a diagram showing the positional relationship of these mechanisms as seen from the direction of the multi-probe head substrate 2010.

The recording medium substrate 2100 is provided opposite to the multi-probe head substrate 2010. Three detection electrodes 2101 for tilt correction are provided on the recording medium substrate 2100.
It is arranged on the portion of the multi-probe head substrate 2010 facing the electrode 2011. Further, electrodes for the recording medium and the recording medium are also arranged on the recording medium substrate 2100. The recording medium substrate 2100 is fixed to the recording medium substrate support 2110. The recording medium substrate support 2110 is scan-controlled in the X and Y directions by an XY scan drive mechanism 2120. Note that these mechanisms are fixed on the support base 2080.

Next, details of the multi-probe head substrate 2010 and the recording medium substrate 2100 will be described with reference to FIGS. 15 (A) and 15 (B).
And FIG. 16 respectively.

The multi-probe head substrate 2010 is shown in FIG.
As shown in FIG. 5 (A), nine probes 2012 _{1 to} 2012 ₉ are arranged in a grid of 3 rows × 3 columns, and three electrodes 2011 for tilt correction are shown in the center of the figure and in the figure. One is arranged at the lower left and one at the lower right in the figure. On the recording medium substrate 2100, as shown in FIG. 15B, three tilt-correction detecting electrodes 2101 are provided on the multi-probe head substrate 20.
One electrode is arranged at a position corresponding to the electrode 2011 on the top 10 (that is, the upper center of the figure, the lower left of the figure and the lower right of the figure). Further, the central portion of the recording medium substrate 2100 in the drawing is a recording area by the probes 2012 _{1 to} 2012 ₉ , and the recording medium 2102 is arranged in this portion. The recording medium 2102 is Au.
It is composed of a two-layer Langmuir-Blodgett film (LB film) made of squarylium-bis-6-octylazulene (SOAZ) laminated on an electrode (JP-A-63-1).
61552 and JP-A-63-161553).

FIGS. 16A and 16B are diagrams showing the details of the tilt-correcting detection electrode 2101 on the recording medium substrate 2100.

The tilt-correction detecting electrode 2101 comprises a first electrode 21 having a notch portion extending from the right center end to the center in the figure.
01 ₁ and a second electrode having a shape similar to the cutout portion provided in the _first electrode 21011 and being inserted into the cutout portion.
Consisting of the electrode 2101 _2. Note that the end of the side to be inserted into the cutout portion of the second electrode 2101 ₂ is provided with fine convex portions 2101 _3, the second electrode 2101 _2, first electrode 2101 ₁
A small convex portion 2101 is formed in the center of the notch provided in the center of the
₃ is inserted into the notch so that it is located.
Incidentally, fine convex portions 2101 _3, for example, JP-A-4-2631
It is possible to manufacture it by using a semiconductor process by the method disclosed in Japanese Patent Laid-Open No. 42-42.

Next, an outline of a probe control signal flow for recording / reproduction and a recording / reproduction signal flow will be described with reference to FIGS. 17 and 18, respectively.

The position control mechanism 3000 shown in FIG. 17 has a probe 3040 and a recording medium which are moved by the Z direction position control circuit 3030 while a predetermined bias voltage is applied from the read bias application circuit 3020 to the electrode substrate 3010. When the distance between the 3001 and the electrode substrate 3010 becomes less than or equal to a predetermined distance,
A tunnel current is detected between the electrode substrate 3010 and the probe 3040 or between the recording medium 3001 on the electrode substrate 3010 and the probe 3040.

The detected tunnel current is converted into a current-voltage converter.
After being converted into a voltage signal by 3060, it is sent to the Z direction position control circuit 3030 and the A / D converter 3070, respectively. In the Z-direction position control circuit 3030, the probe is adjusted so that the distance between the electrode substrate 3010 and the probe 3040 or the distance between the recording medium 3001 and the probe 3040 becomes constant based on the detected tunnel current value. A position control signal for controlling the position of the 3040 is created. On the other hand, the A / D converter 3070 is provided with a filter (not shown) for anti-aliasing, and the A / D converted tunnel current data is stored in the bit data extraction circuit 30.
It is sent to 80 and separated into bit signals (“0” and “1” signals). Specifically, for example, the recording medium 30
"01" is the part where the conductivity has changed (hatched part in Fig. 17)
1 ", and the part that has not changed is set to" 0 ".
On the other hand, the write pulse voltage having a predetermined voltage value is applied from the write pulse applying circuit 3100 between the probe 3040 and the electrode substrate 3010, thereby recording data.

Operations on the surface of the recording medium are performed by the stage 3110. When the scan control signal S _C is externally input to the stage operation control circuit 3120, the X direction scan signal S _X and the Y direction scan signal S _Y are generated by the stage operation control circuit 3120 according to the instruction indicated by the scan control signal S _C. To be done. X
The direction scanning signal S _X and the Y direction scanning signal S _Y are amplified by the first amplifier 3130 and the second amplifier 3140, respectively, and then applied to an actuator such as a piezoelectric element attached to the stage 3110. This makes the stage 31
10 is scan-controlled.

Although only one tunnel current detection system is shown in FIG. 17, when it is actually used,
It is designed to be performed by a plurality of probe sets in consideration of the data transfer rate.

For position control in the Z direction, as shown in FIG. 18, a bimorph cantilever 3310 using a piezoelectric material manufactured by a semiconductor process is used, and its operation is Z
It is controlled by the directional position control circuit 3350. The tunnel current signal is converted into a current voltage by the tunnel current detection circuit 3360 and then converted into a digital voltage value on the data bus 3370.
It is output to the above and is received by the Z direction position control circuit 3350 and the bit information extraction circuit 3380. Bit information extraction circuit 33
At 80, bit information is extracted from the magnitude of the input signal, and the extracted bit information is output onto the data bus 3370. On the other hand, the data output on the data bus 3370 is received by the write pulse application circuit 3400, so that the data is written.

Although only the control system for one probe unit is shown in FIG. 18, this is actually in parallel, and three switches 3411 to 3413 are opened and closed for each probe. As a result, multiple probes are multiplex-controlled by one set of control system. Control of the switches 3411 to 3413 is performed by a timing control circuit (multiplexer) 3420.

Next, the actual inclination correction will be described in detail with reference to FIG.

The inclination correction control system shown in FIG. 19 basically has the same configuration as that shown in FIG. 11 for the number of electrodes (that is, three).

The detection voltage values generated in the _three read resistors 4115 _{1 to} 4115 3 are converted into DC signals corresponding to the maximum detection voltage value by the signal detection circuits 4201 _{1 to} 4201 ₃ , respectively. The DC signals converted by the _three signal detection circuits 4201 _{1 to} 4201 ₃ are respectively amplified by the gain-adjustable amplifiers 4202 _{1 to} 4202 ₃ and then input to the position detection circuit 4116. The position detection circuit 4116, the three amplifiers 4202 _{1-4202 third} output signals, each position is calculated. The output signal of the position detection circuit 4116 is input to the position control circuit 4117. The position control circuit 4117 calculates each control amount so that each position indicated by the output signal of the position detection circuit 4116 is matched with the set position preset by the sequence control circuit 4203. Position control circuit 41
Each control amount calculated in 17 is output to a drive mechanism (not shown) (see FIG. 11).

Now, for example, the minute convex portion 4114 _{1 at the} left end of the figure.
If a potential drop due to occurs, the drive mechanism at the corresponding position is stopped, and the position detection circuit 4116 operates as shown in FIG.
Voltage drop position detects that shown in, and calibrates the gain of the amplifier 4202 ₁ of the previous stage according to the detected voltage drop position to correct the detected variation of the detection electrodes. As a result, the small convex portion
Even in the position detection at a distance of 2 nm or more where 4114 ₁ does not act, positioning can be performed with higher accuracy.

The position control mechanism also works effectively when the inclinations of the multi-probe head substrate and the recording medium substrate are corrected to match the surfaces. Figure 1 shows each position detection unit
By controlling to the position where the drop of the detection voltage shown in 2 starts to appear, the distance between the two electrodes is controlled to a height according to the height accuracy at the time of manufacturing the minute convex portion, and thus at least 0.
The distance between the two electrodes is controlled with an accuracy of 1 μm or less, and the plane parallelism of the two substrates is realized with an accuracy corresponding to that.

Further, since it is not influenced by the detection sensitivity variation in each electrode, the inclination of the surface can be corrected without the two substrates coming into contact with each other. For example, the electrodes 20 on the multi-probe head side shown in FIG.
Even when the surface misalignment between 11 and the detection electrode 2101 on the recording medium substrate side occurs in the XY directions, the signals output from the respective electrodes have variations in sensitivity. Even in such a case, the absolute position can be grasped by the minute convex portion, and the gain can be adjusted by that, and the surface distance control can be performed with high accuracy.

[0113]

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

The invention according to any one of claims 1 to 12 (the surface aligning method of the present invention) corresponds to the surface alignment of the recording medium or the recording information at the time of low speed scanning for the surface alignment of the scanning surface and the surface of the recording medium. The distance between the probe electrodes and the recording medium during high-speed scanning can be increased by performing coarsely according to the signal to be recorded and by accurately performing from the signal component corresponding to the parasitic vibration of the relative movement mechanism during high-speed scanning. Since it can be controlled with sub-micron accuracy, for example, a writing error at the time of recording information in a recording / reproducing apparatus using the principle of the scanning probe microscope or applying the principle of the scanning probe microscope, and The read error can be improved. Further, since the scanning can be performed at a higher speed than that of the conventional surface matching method, the information can be recorded at a higher speed and the recorded information can be reproduced at a higher speed.

The invention according to claim 13 and claim 14 (the position control mechanism of the present invention) includes a minute convex portion electrically projecting to the surface of the first plate electrode and electrically grounded. Since the absolute distance between the first substrate and the second substrate in capacitance detection can be measured with high precision, it is possible to avoid collision and contact between the first substrate and the second substrate, and Despite the detection system based on electrostatic capacitance detection, highly accurate interval control can be performed.

According to the fifteenth aspect of the present invention (the information processing apparatus of the present invention), by including the position control mechanism of the present invention, it is possible to accurately record information on the recording medium and reproduce the recorded information from the recording medium with high accuracy. It can be carried out.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a recording / reproducing apparatus capable of realizing a first embodiment of a surface matching method of the present invention.

FIG. 2 is a diagram for explaining a configuration of a plurality of probe electrodes shown in FIG.

FIG. 3 is a view of the plurality of probe electrodes shown in FIG.
It is a sectional view taken along the line A.

FIG. 4 is a plan view of a plurality of probe electrodes shown in FIG.

FIG. 5 is a diagram for explaining the basic principle of the surface matching method of the present invention.

FIG. 6 is a diagram for explaining the basic principle of the surface matching method of the present invention.

FIG. 7 is a diagram for explaining the basic principle of the surface matching method of the present invention.

8 is a graph showing the relationship between the scanning mechanism drive signal and the displacement of the probe electrode in the Z direction during low-speed scanning in the recording / reproducing apparatus shown in FIG.

9 is a graph showing the amount of change between the scanning mechanism drive signal and the tunnel current during high-speed scanning in the recording / reproducing apparatus shown in FIG.

FIG. 10 is a graph showing the amounts of change in the scanning mechanism drive signal and the tunnel current during low-speed scanning in the second embodiment of the surface alignment method of the present invention using the constant height mode as the rough surface alignment method.

FIG. 11 is a diagram for explaining the operation of the embodiment of the position control mechanism of the present invention.

12 is a graph showing an example of detected voltage values in the position control mechanism shown in FIG.

FIG. 13 is a schematic configuration diagram showing an embodiment of the position control mechanism of the present invention.

14 is a diagram showing the positional relationship of the mechanism shown in FIG. 13 as viewed from the direction of the multi-probe head substrate.

FIG. 15 is a diagram for explaining the details of the multi-probe head substrate and the recording medium substrate shown in FIG.
FIG. 3A is a diagram for explaining the details of the multi-probe head substrate, and FIG. 7B is a diagram for explaining the details of the recording medium substrate.

FIG. 16 is a diagram showing details of a tilt correction detection electrode on the recording medium substrate shown in FIG. 13, FIG.
(B) is a side view.

FIG. 17 is a block diagram for explaining an outline of a probe control signal flow for recording / reproduction and a recording / reproduction signal flow.

FIG. 18 is a block diagram for explaining time division control when controlling a plurality of probes.

FIG. 19 is a schematic diagram for explaining a surface spacing control operation and a surface parallelism control operation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 recording medium 1 ₁ mica substrate 1 ₂ base electrode 1 ₃ organic recording layer 10 recording / reproducing device 11 multiple probe electrodes 12 probe electrode attachment 13 first tilt mechanism 14 Z direction fine / coarse mechanism 21 second tilt mechanism 22 XY direction fine movement / coarse movement mechanism 31 Interface 32 Control circuit 33 Writing / reading circuit 34 Bias circuit 35 Tunnel current detector 36 Position detecting circuit 37 Positioning circuit 38 Servo circuit 39 Z direction driving circuit 40 XY direction driving circuit 41 Divider 42 Tilt Mechanism drive circuit 100 Probe electrode 105 Multi-probe substrate 110 Cantilever 111,114 Upper electrode 112 Middle electrode 113,115 Lower electrode 116 First piezoelectric thin film 117 Second piezoelectric thin film 120 Probe 121 Extraction electrode 210 XY direction fine movement mechanism 201 samples (recording medium) 211 probe (probe electrode) I _WR writing and reading Distribution S _D sample drive signal D _D probe electrode Z direction displacement S scanning mechanism drive signal I _T tunneling current X, Y, Z-axis 1000 position control mechanism 1110,4110 AC power source 1111,4111 _{1-4111 third} bias resistor 1112,4112 ₁ ~ 4112 ₃ Upper electrode 1113, 4113 ₁ ~ 4113 ₃ Lower electrode 1114, 4114 ₁ ~ 4114 ₃ Small convex portion 1115, 4115 ₁ ~ 4115 ₃ Read resistance 1116, 4116 Position detection circuit 1117, 4117 Position control circuit 1118 Drive mechanism 1119 Above Substrate 1120 Lower substrate 2000 Position control mechanism 2010 Multi-probe head substrate 2011 Electrode 2012 _{1 to} 2012 ₉ Probe 2020 Multi-probe head substrate support 2030 Support rod 2040 Piezo element 2050 DC servo motor 2060 Tension spring 2070 Z direction drive mechanism 2080 Support 2100 recording medium substrate 2101 detection electrodes 2101 ₁ first electrode 2101 ₂ second electrode 2101 ₃ minute projections 2102 recording medium 2110 recording medium substrate support 2120 XY scanning driving mechanism 3000 position control mechanism 3001 records Body 3010 Electrode substrate 3020 Read bias application circuit 3030 Z direction position control circuit 3040 Probe 3060 Current voltage converter 3070 A / D converter 3080 Bit data extraction circuit 3100 Write pulse application circuit 3110 Stage 3120 Stage operation control circuit 3130 First Amplifier 3140 Second amplifier S _C Scan control signal S _X X direction scan signal S _Y Y direction scan signal 3310 Bimorph cantilever 3350 Z direction position control circuit 3360 Tunnel current detection circuit 3370 Data bus 3380 Bit information extraction circuit 3400 Write pulse application circuit 3411 to 3413 Switch 3420 Timing control circuit (multiplexer) 4201 _{1 to} 4201 ₃ Signal detection circuit 4202 _{1 to} 4202 ₃ Amplifier 4203 Sequence control circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimitsu Kawase 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shunichi Shito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Kunihiro Sakai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takahiro Oguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Akihiko Yamano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (15)

[Claims] 1. A recording medium for recording information, a plurality of probe electrodes provided to face the recording medium for applying a predetermined voltage to the recording medium, and a plurality of probe electrodes. A first surface aligning unit having a first tilt mechanism for correcting the tilt; a second surface aligning unit having a second tilt mechanism for correcting the tilt of the recording medium; and the recording medium. Relative movement means for relatively moving the plurality of probe electrodes, the plurality of probe electrodes while detecting the interaction depending on the distance between the plurality of probe electrodes and the recording medium. A surface used for an information processing device for performing relative scanning with respect to the recording medium, for performing surface alignment between a scanning surface generated by relative movement of the plurality of probe electrodes and the recording medium and a surface of the recording medium. In the aligning method, when the recording medium is scanned at low speed by the relative moving means, a signal corresponding to a surface state or recording information of the recording medium obtained by detecting the interaction is obtained. Accordingly, using at least one of the first tilt mechanism and the second tilt mechanism,
When the scanning surface and the surface of the recording medium are roughly aligned, and when the recording medium is scanned by the relative moving means at high speed with respect to the plurality of probe electrodes, the interaction is detected to obtain the The first tilt mechanism and the second tilt so that the amplitude of the signal component corresponding to the nth natural frequency (n = 0, 1, 2, ...) Of the relative moving means is set to zero or the minimum value. A surface aligning method, wherein at least one of the mechanisms is used to perform precise surface alignment between the scanning surface and the surface of the recording medium. 2. The scanning is performed so that the amplitude of the signal component corresponding to the scanning frequency of the relative moving means, out of the signal components of the signal corresponding to the surface state of the recording medium or the recording information, becomes zero or the minimum value. 2. The surface matching method according to claim 1, wherein rough surface matching between the surface and the surface of the recording medium is performed. 3. The surface aligning method according to claim 1, wherein the first tilt mechanism and the second tilt mechanism each include a piezoelectric element. 4. The rough surface alignment and the precise surface alignment between the scanning surface and the surface of the recording medium are performed by using any one probe electrode of the plurality of probe electrodes. The surface matching method according to any one of claims 1 to 3. 5. The first surface matching means and the second surface matching means.
3. The surface aligning method according to claim 2, wherein each of the surface aligning means has a lock-in amplifier for detecting the amplitude of a signal component corresponding to the scanning frequency of the relative moving means. 6. The probe electrode according to claim 1, wherein each of the plurality of probe electrodes has a cantilever having a bimorph structure or a unimorph structure, and a probe formed on the cantilever. Face to face method. 7. The surface aligning method according to claim 1, wherein the interaction depending on the distance between the plurality of probe electrodes and the recording medium is a tunnel current. 8. The surface aligning method according to claim 1, wherein the interaction depending on the distance between the plurality of probe electrodes and the recording medium is an atomic force. . 9. The surface alignment method according to claim 1, wherein the interaction depending on the distance between the plurality of probe electrodes and the recording medium is magnetic force. 10. The surface matching method according to claim 1, wherein the interaction depending on the distance between the plurality of probe electrodes and the recording medium is ion conduction. 11. The surface matching method according to claim 1, wherein the interaction depending on the distance between the plurality of probe electrodes and the recording medium is acoustic. 12. The surface alignment method according to claim 1, wherein the interaction depending on the distance between the plurality of probe electrodes and the recording medium is evanescent light. 13. A first substrate, a first plate electrode arranged on the first substrate, a second substrate provided so as to face the first substrate, and a second substrate. A second plate electrode disposed on the substrate, and an AC power supply for applying a predetermined AC voltage between the first plate electrode and the second plate electrode, the first plate electrode And a change in the potential difference between the first flat plate electrode and the second flat plate electrode from the change in the capacitance value formed by the second flat plate electrode and the first substrate. A position control mechanism for controlling a distance from the second substrate, further comprising an electrically grounded micro-projection projectingly provided on the surface of the first plate electrode. The first plate electrode and the second plate electrode by electrically contacting a part of the portion with a part of the second plate electrode Distance of the voltage drop occurs between the first substrate and the second position control mechanism, characterized in that to adjust the distance between the substrates. 14. A voltage drop between the first flat plate electrode and the second flat plate electrode caused by a part of the minute convex portion electrically contacting a part of the second flat plate electrode. From the above, the distance between the first substrate and the second substrate is determined, and the potential difference between the first flat plate electrode and the second flat plate electrode is corrected according to the determined distance. 14. The position control mechanism according to claim 13, further comprising a correction unit. 15. A probe, a recording medium provided so as to face the probe, and the probe and the recording medium are brought close to each other to relatively scan the probe and the recording medium. A scanning mechanism, a recording unit for causing the probe to physically change a minute area of the recording medium to record information in the minute area during scanning by the scanning mechanism, and a scanning unit for scanning by the scanning mechanism. Detecting means for detecting a minute signal obtained from the interaction between the probe and the recording medium, and reproducing means for reproducing the information recorded on the recording medium from the output signal of the detecting means. In an information processing apparatus, a substrate on which the plurality of probes are arranged, and a distance between the substrate and the recording medium are controlled.
An information processing apparatus further comprising the position control mechanism according to claim 3 or claim 14.