JP3023728B2 - Probe structure, recording device, information detecting device, reproducing device, and recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording information and / or reproducing information.

[0002]

2. Description of the Related Art An information storage element or an information storage device, a so-called memory, is not only the core of a computer and its related equipment, but also a video device, such as a video disk and a digital audio disk.
It occupies an important position in audio equipment. The performance required of this memory depends on its application, but in general, it is high density, large recording capacity, fast response time of recording and reproduction, low power consumption, high productivity, low price, At present, the development of a memory system and a memory medium for realizing such performance is being actively promoted.

Conventionally, the center of memory has been a magnetic memory using a magnetic material or a semiconductor as a material, and a semiconductor memory.
In recent years, with the progress of laser technology, inexpensive and high-density optical memories using organic thin films such as organic dyes and photopolymers have appeared.

At present, technology development for miniaturization of unit memory bits is proceeding to further increase the density and the capacity of these memories, but the principle is completely different from those of the conventional memories. There is also a proposal for a memory based on it. For example, the concept of a molecular electronic device in which individual organic molecules have functions of a logic element and a memory element is one of them. Although it can be seen that molecular electronic devices have advanced the miniaturization of unit memory bits to the limit, how to access individual molecules has been a problem so far.

On the other hand, recently, a scanning tunneling microscope (hereinafter, referred to as “ST”) capable of directly observing the electronic structure of surface atoms of a conductor.
M ”) has been developed and [G. Binnig et
al. , Helvetica Physica Act
a, 55 , 726 (1982)] Real space images can be observed with high resolution regardless of whether they are single crystals or amorphous. S
TM has the advantage that it can be observed at low power without damaging the sample due to electric current. Furthermore, it can be operated in air and can be used for various materials, so it can be applied to a wide range of applications. Is expected. Recently, it has been reported that even a molecular image of an organic molecule adsorbed on a conductor surface can be observed.

On the other hand, an atomic force microscope (hereinafter, referred to as “AFM”) to which the STM technique is applied has been developed, and [G. B
innig et al. Phys. Rev .. Let
t. , 56 , 930 (1985)] As in the case of the STM, it is possible to obtain surface unevenness information. AFM
Can be measured on an atomic order even for insulating samples, so future development is desired.

[0007] The STM utilizes the fact that a tunnel current flows when a voltage is applied between a metal probe (hereinafter referred to as a "probe electrode") and a conductive substance so that the distance between them is reduced to about 1 nm. This current is extremely sensitive to a change in the distance between the two, and by scanning the probe electrode over the surface of the conductive material while controlling the distance between the two so as to keep the tunnel current constant, The user can not only draw the surface structure in real space, but also read various information about the total electron cloud of surface atoms. At this time, the resolution in the in-plane direction is about 1 °. Therefore, S
If the principle of TM is applied, it will be enough in atomic order (number 十分)
It is possible to perform high-density recording / reproduction on a computer. At this time, as a recording / reproducing method, a particle beam (electron beam, ion beam)
Alternatively, recording is performed by changing the surface state of an appropriate recording layer using high-energy electromagnetic waves such as X-rays and energy rays such as visible / ultraviolet light, and a method of reproducing by STM or applying a voltage to the recording layer is used. A medium having a switching characteristic of transitioning to a state having a different conductivity, and having a memory characteristic in which each state having a different conductivity is retained even when no voltage is applied, for example, a π-electron conjugated system. A method of performing recording and reproduction by STM using a thin film layer of an organic compound or a chalcogen compound containing abundantly has been proposed (JP-A-63-161552, JP-A-63-16163).
No. 1553).

[0008]

A reproducing method in an information recording and / or reproducing apparatus to which the STM is applied scans a probe electrode on a medium surface while maintaining a constant current flowing between the probe electrode and the recording medium surface. Then, by utilizing the fact that the probe electrode moves away from the medium surface in the region of high conductivity, the amount of movement of the probe electrode is detected to reproduce the recorded bit, or the distance between the probe electrode and the recording medium is kept constant. The probe electrode is scanned over the surface of the medium while holding it, and the amount of current flowing between the probe electrode and the surface of the recording medium is increased over the area of high conductivity. I do.

However, when the former reproducing method is adopted, the probe electrode follows even the slight irregularities of the recording medium, and therefore, the discrimination between the irregularities on the medium surface and the recording bits is made only from the movement amount of the probe electrode. It is difficult to do so, causing read error problems. Further, the controllable scanning frequency is limited by the upper limit of the band of the feedback control circuit for keeping the current constant, so that high-speed scanning has been difficult. In addition, in the case of the latter reproducing method, high-speed scanning is possible, but the amount of current changes due to irregularities on the surface of the medium, and the reading error problem occurs as in the former method. Furthermore, the probe electrode and the medium surface are separated by a certain distance, and this acts as an insulating barrier.This barrier is common to the write bit write area and the area where it is not, and is effectively connected in series as a tunnel resistance. Will be inserted. For this reason, the ratio of the amount of current detected between the written portion and the non-written portion greatly differs depending on the distance between the probe electrode and the medium surface, which may pose a problem when reading bits accurately.

Therefore, the reproduced signal needs to have a component separated by the unevenness of the recording medium, and the tunnel resistance caused by the insulating barrier between the probe electrode and the surface of the recording medium is kept as small and constant as possible. Therefore, it is necessary to increase the reproduction signal ratio depending on the presence or absence of recording bits as much as possible. Also, at the time of recording, it is preferable that a change in applied voltage due to recording hardly affects the control of the distance between the probe electrode and the medium.

Further, when the distance between the recording medium and the probe electrode is large, it is preferable that the resolution as the STM decreases, that is, from the viewpoint of the recording density, the recording medium and the probe electrode are as close as possible.

In order to remove components due to irregularities on the medium surface from the reproduced signal and to make the interval control during recording independent of the applied voltage, the distance between the medium surface and the probe is determined by an amount other than the current flowing between them. Japanese Patent Laid-Open Publication No. 1-245445 discloses a method of controlling the distance constant by using an atomic force microscope (AFM) in which the distance is controlled by an atomic force acting between the two.

In the AFM, the probe electrode is supported by an elastic body, and the force acting between the tip of the probe electrode and the surface of the recording medium is balanced with the spring force due to the deformation of the elastic body, and the feedback is performed so as to keep this deformation constant. Control is performed.

In a device for recording and / or reproducing information, as a method of controlling the distance between the probe and the information recording medium in a simpler manner by using the atomic force, an elastic body supporting the probe is controlled by the probe / information recording medium. By arranging the probe / information recording medium so that the force for deforming in the direction of correcting the medium interval fluctuation acts between the probe / information recording medium, the probe / information recording medium interval is kept constant without feedback control. There is a way to keep it.

By the way, in order to make the probe follow irregularities on the surface of the recording medium without performing feedback control, the spring constant of the support for the probe electrode is made as small as possible, and the range of the deformation amount at which the support maintains elastic deformation is obtained. It is necessary to take a wide design and to make the elastic force small. However, if the spring constant is reduced, the mechanical resonance frequency of the support decreases, and high-speed operation cannot be performed, and the support is deformed by the influence of microscopic frictional force during scanning. There is a limit to reducing the spring constant of the support. That is, when the feedback control is not performed, there is a limit to the height difference of the irregularities on the medium surface that the probe can follow.

On the other hand, the surface of the medium has undulations or inclinations having a spatial frequency lower than this, in addition to irregularities having the same spatial frequency as data bits that need to be separated particularly during reproduction. There are many. These often have a greater height difference than the above-mentioned unevenness, and even if the above-described unevenness of the unevenness is small, the probe without feedback control due to such undulation and inclination. Often exceeds the height difference of the irregularities that can be followed. In addition, when a plurality of probe electrodes and their supports are integrated, a possible value of the spring constant may be further limited in consideration of correcting variations in probe electrode tip positions.

[0017]

SUMMARY OF THE INVENTION The present invention relates to an object
To read and / or input information to the
To the probe structure and the information recording medium
Recording device for recording information through a probe, detecting information
Detecting device, reproducing device for reproducing information, and recording and
In a recording / reproducing apparatus for reproducing, a support for supporting a probe is provided.
The holding body is the first elastic body or micro
An elastic body, having a lower resonance frequency than the first elastic body
To change the distance between the probe and the information recording medium.
Two-stage structure joined to a second elastic body having a driving function for
It has the characteristic that it was completed.

Further, by disposing the probe / information recording medium such that a force for deforming the microelastic body in a direction for correcting a variation in the distance between the probe / information recording medium acts on the probe / information recording medium. The probe / information recording medium interval is controlled, and the second elastic body has a resonance frequency sufficiently lower than a mechanical resonance frequency of the microelastic body, and a driving mechanism thereof.
It is characterized in that the deformation amount of the minute elastic body is deformed so as not to exceed a predetermined value, and the deformation amount of the minute elastic body is always kept within a predetermined range.

By the above means, irregularities on the medium surface, undulation or inclination of the medium surface, which cannot be completely followed by the minute elastic body, can be followed by the second elastic body. For this reason, the spring constant of the microelastic body can be set to a value that does not show the effect of microscopic frictional force and allows high-speed operation. further,
Even when a plurality of probe electrodes and their supports are integrated, variations in probe tip positions can be corrected by the second elastic body.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

FIG. 1 shows a detailed structure of a probe electrode and a support for the probe electrode according to the present invention. In the figure, 1 is a probe electrode, 2 is a support, and 3 is a probe electrode driving mechanism. The support 2 of the probe electrode is formed of SiO ₂ on the free end side of the second elastic body 2 b having a cantilever structure made of SiO _2.
2 and a two-stage structure of a micro elastic body 2a having a cantilever structure and formed integrally with the second elastic body 2b. The probe electrode 1 is formed on the free end side of the micro elastic body 2a, and the metal electrodes 3a, 3 are formed on the second elastic body 2b.
a ′, 3a ″ and piezoelectric thin films 3b, 3b ′ made of AlN
Are alternately laminated to form a piezoelectric actuator having a bimorph structure. By applying a voltage between the metal electrodes 3b and 3b ', the second elastic body 2b can be driven to bend at least in the out-of-plane direction of the piezoelectric thin film.

The tip of the probe electrode 1 is used for recording / reproducing /
In order to improve the erasing resolution, it is better to sharpen as much as possible. In theory, by sharpening to the atomic / molecular level, it is possible to obtain the resolution in the order of atoms / molecules. As a method for forming the probe electrode 1, for example, S
iO implant ₂ Si on at Focused ion beam by selectively crystallized Si on a Si forming the tip, it performs a conductive coating by depositing Au thereon. These are integrally formed on a silicon wafer by micromechanics technology. The structure of the elastic body as the support 2 of the probe electrode is not limited to the cantilever. Also,
The actuator is not limited to the bimorph structure as well, as long as the actuator can move so that the tip of the probe electrode can approach the recording medium surface, and the constituent materials thereof are not limited to the above-mentioned materials. It is not limited to forming the elastic body 2a and the second elastic body 2b integrally. Further, the shape, the forming method, and the treatment of the probe electrode 1 are not limited to those described above.

FIG. 2 shows an overall configuration diagram of a recording / reproducing apparatus having the above mechanism. In the figure, reference numeral 4 denotes a recording medium, on which a recording layer 4a is formed on an electrode 4b. 5 is a medium fine movement mechanism, 6
Reference numeral denotes a medium coarse movement mechanism. The fine movement control circuit 8 and the coarse movement control circuit 9 perform three-dimensional coarse movement and fine movement displacement of the recording medium 4 with respect to the probe electrode 1, respectively. The probe electrode 1 and its support 2 are fixed to the probe electrode support mechanism 16, and the support mechanism 16 and the coarse movement mechanism 6
Is fixed to the base 7. The base 7 is installed on a seismic isolation table (not shown). Reference numeral 12 denotes a voltage application circuit which performs recording, reproduction, and recording between the probe electrode 1 and the recording medium 4.
A voltage for erasing is applied. A current detection circuit 11 detects a current flowing between the probe electrode 1 and the recording medium 4. The drive of the probe electrode drive mechanism 3 is controlled by a probe electrode drive mechanism control circuit 15.

In this embodiment, the tip of the probe electrode 1 and the surface of the recording medium 4 are brought close to the distance at which the repulsive force acts, and the probe electrode 1 is removably elastically deformed by the repulsive force. 4 on the surface, simultaneously applying a medium change voltage between the probe electrode 1 and the recording medium 4 to perform recording and erasing, and applying a very small voltage to detect a current flowing through the recording medium, thereby making the conductivity different. region,
That is, the recording bit is detected.

Since the microelastic body is used in an elastically deformed state due to a repulsive force acting between the tip of the probe electrode and the surface of the recording medium, if the tip of the probe electrode approaches the surface of the medium due to unevenness on the surface of the medium and the repulsive force increases, the minute The deformation of the elastic body increases, the tip of the probe electrode moves away from the medium surface, and if the tip of the probe electrode moves away from the medium surface and the repulsion decreases, the deformation of the microelastic body decreases and the tip of the probe electrode approaches the medium surface, If the amount of deformation of the microelastic body due to surface irregularities during scanning is within the range of elastic deformation, the distance between the probe electrode 1 and the medium surface 4 is controlled by feedback by the amount of deformation of the microelastic body by mounting an actuator on the microelastic body. Even if it is lost, it will be kept almost constant.

Further, like the undulation and inclination of the medium surface,
Although the change in the spatial frequency is smaller than the spatial frequency of the data bit, the second elastic body 2b is deformed by the probe electrode driving mechanism 3 for a height difference exceeding the range of elastic deformation of the minute elastic body. The control is performed such that the deformation of the microelastic body is always within the range of the elastic deformation. At this time, since the second elastic body does not need to follow the same spatial frequency as the data bit, the mechanical resonance frequency of the second elastic body may be set higher than the spatial frequency of the data bit. Preferably, the coupling between the natural vibration mode of the second elastic body and the natural vibration mode is set to a value that can be ignored.

In order to control the deformation of the second elastic body so that the deformation of the minute elastic body is within the range of the elastic deformation, for example, the fluctuation of the current flowing between the probe electrode and the medium surface is used, Among them, there is a method of performing feedback control by using a part of components in a frequency range lower than the mechanical resonance frequency of the second elastic body. That is, when the microelastic body is largely deformed and the current gradually increases (decreases), the feedback control of the probe electrode driving mechanism may be performed so that the second elastic body is deformed in a direction to compensate for the increased (decreased) portion. . As a result, it is possible to absorb a level difference that is gentle such as undulation or inclination of the medium surface but exceeds the elastic deformation range of the microelastic body.

The signal for controlling the feedback of the second elastic body is not limited to the current flowing between the probe and the surface of the recording medium, but may be any signal that can be converted into the amount of deformation of the minute elastic body. For example, a signal directly detecting the deformation of the microelastic body or a signal detecting a change in stress due to the deformation may be used.

The entire apparatus is centrally controlled by the microcomputer 10.

Note that the mechanism is not limited to the above-described structure as long as the mechanism changes the relative positional relationship between the probe electrode 1 and the recording medium 4. For example, a coarse movement mechanism and a fine movement mechanism may be provided on the support mechanism side of the probe electrode, or a movement mechanism may be provided on both the support mechanism side and the recording medium side.

The recording medium used in the present invention may be any medium as long as its conductive state changes when a voltage is applied and the conductive state is maintained without applying a voltage. The Japanese
And a medium composed of an organic material having a group having a π-electron level disclosed in JP-A-161552 and JP-A-63-161553, and more preferably LB.
And a monomolecular accumulation film of the organic material formed by the method.

M in which the monomolecular accumulation film is sandwiched between metal electrodes
The IM structure element (FIG. 8) exhibits current-voltage characteristics as shown in FIGS. 9 and 10 (see Japanese Patent Application Laid-Open No. 63-96956). The two states (the ON state and the OFF state) transit to each other by applying a voltage higher than the threshold, and each state is maintained below the threshold voltage. Although it is expressed, as the recording medium in the present invention, as disclosed in JP-A-63-161552 and JP-A-63-161553, a recording medium having a thickness of several to 500 mm is preferable. Most preferably, it has a film thickness of 10 to 200 degrees.

The electrode material used in the present invention may be any material having a high conductivity. For example, Au, P
Many materials including metals such as t, Ag, Pd, Al, In, Sn, Pb, and W and alloys thereof, and further, graphite and silicide, and further, conductive oxides such as ITO, These applications to the present invention are conceivable. As a method for forming an electrode using such a material, a conventionally known thin film technique is sufficient. However, as the electrode material formed directly on the substrate, it is preferable to use a conductive material that does not form an insulating oxide film when the LB film is formed on the surface, for example, an oxide conductor such as a noble metal or ITO.

The metal electrode of the recording medium is required when the recording layer according to the present invention has a high insulating property. However, if the recording layer has a semiconductor property of MΩ or less, the metal electrode may be used. Becomes unnecessary.

Hereinafter, a probe having a width of 15
A second elastic body having a rectangular shape of 0 μm and a length of 600 μm;
2 made of a V-shaped microelastic body having a length of 0 μm and a length of 100 μm
An embodiment of recording / reproduction / erasing using a step cantilever will be described.

The resonance frequency of the microelastic body is about 27 kHz,
The resonance frequency of the second elastic body was about 2.5 kHz.
Under this condition, the coupling between the two natural vibrations can be almost ignored.

After fixing the recording medium 4 on the xyz fine movement device 5, a bias voltage of 100 mV is applied between the probe electrode 1 and the Au electrode 4b, and the xyz coarse movement device 6 and x
The yz fine movement device 5 is driven to bring the medium 1 closer to the probe electrode 2. By changing the distance between the probe electrode 2 and the recording medium 4 while monitoring the current flowing between them, a current characteristic as shown in FIG. 3 was obtained.

On the other hand, when the probe electrode 1 and the recording medium 4 approach each other, a force acts between them, and this force causes the cantilever 3 to move.
Is deformed. Using an optical lever system for detecting the amount of deformation based on the deviation of the reflected beam from the cantilever beam of the laser beam, the result of measurement simultaneously with the current characteristics is also shown in FIG.
It is shown in

In a region a in FIG. 3 where a repulsive force acts between the probe electrode 1 and the recording medium 4, the current flowing between them has a gradual change with respect to the distance between them. Thereafter, the probe electrode 1 and the recording medium 4 were brought close to a distance where a repulsive force acts between them by controlling the current by monitoring the current.

The distance between the probe electrode 1 and the recording medium 4 is reduced to the state of the area a in FIG.
The output of the control circuits 8 and 9 of the yz coarse movement device 6 is held and turned on.
Measuring the current a triangular wave pulse voltage having the waveform shown in FIG. 4 is a threshold voltage V _{th on} more voltage generated state by applying a bias again 100mV after applying between the probe electrode 2 and the Au electrode 4b Then, a current of about 8 μA flowed, indicating that the device was turned on.

Next, after applying a triangular pulse voltage having a waveform shown in FIG. 5 which is equal to or higher than the threshold voltage V _{th OFF which} changes from the ON state to the OFF state, a bias of 100 mV is applied again. OFF at about 1nA
It was confirmed to return to the state.

Next, in the same manner as described above, with the distance between the probe electrode 2 and the recording medium 1 approaching the state of the area a in FIG. 3, the y, z axes of the xyz fine movement device 5 are fixed, and When only the current was driven and the current was monitored, the current value was almost 1
A constant value of nA was shown. Next, while driving only in the x-axis direction, the threshold voltage V _th having the waveform of FIG.
After applying a triangular pulse voltage of “ _on” or more between the probe electrode 1 and the Au electrode 4b, the driving in the x-axis direction is repeated again under a constant bias of 100 mV, and the current flowing between the probe electrode 2 and the Au electrode 4b is reduced. When measured,
With a 10 nm period, a current that changes by about four digits is observed,
It was confirmed that the ON state was periodically written. Further, the ratio of the current between the ON state and the OFF state also maintained a substantially constant value.

The area where the ON state is periodically written is again scanned only by the x-axis drive, and an arbitrary ON state is turned on.
While the xyz fine movement device 5 was stopped on the state area and this position was held, a triangular wave pulse voltage having a waveform of FIG. 5 and a threshold voltage V _{th OFF} or more was applied. The scanning in only the x-axis direction was repeated, and the current was measured. As a result, the ON state of the area to which the pulse was applied was erased, and the OF showing a current of about 1 nA
It was confirmed that it returned to the F state. Similarly to this arbitrary bit erase, the voltage between the probe electrode 2 and the Au electrode 4b is set to be equal to or higher than the threshold voltage V _{th OFF} , the recording area is scanned, and then the current is measured. The current value is about 1 nA. It showed a substantially constant value, and it was confirmed that all the ON states recorded in a 10 nm cycle were erased and turned OFF.

Subsequently, the xyz fine movement device 5 is controlled to 1 nm
When stripes having a length of 1 μm were written at various pitches between 1 μm and 1 μm by the above method and the resolution was measured,
At a pitch of 3 nm or more, a current change of about four digits was always confirmed at the same pitch as the writing pitch, but at a pitch of less than 3 nm, the change of the current amount gradually became smaller.

Further, as the operating conditions of the apparatus, the above-mentioned recording, reproduction, and erasing were performed with a probe scanning range of 1 μm square and a scanning speed of 50 Hz / line. At this time, the high frequency cutoff frequency was set to 200 Hz using the output of the current detection circuit, and the probe electrode driving mechanism 3 was feedback-controlled by a frequency component of 200 Hz or less of the output. Under these operating conditions, no trouble occurred in reading data bits and the like. That is, under these conditions, the data bit has a spatial frequency of about 10 kHz, but it is considered that the microelastic body sufficiently followed the same degree of unevenness. Further, the component used for the feedback control corresponds to the swell corresponding to several cycles in the 1 μm region, and it is considered that the swell or the inclination was sufficiently followed.

The recording medium was prepared as follows.

After cleaning the optically polished glass substrate (substrate 4c) using a neutral detergent and trichlene, Cr is deposited as a subbing layer by a vacuum deposition method to a thickness of 50 °, and Au is further deposited to a thickness of 400 ° by the same method. A base electrode (Au electrode 4b) was formed.

Next, squarylium-bis-6-octylazulene (hereinafter referred to as "SOAZ") having a concentration of 0.2 mg
/ Ml of chloroform solution was developed on an aqueous phase at 20 ° C to form a monomolecular film on the water surface. The surface pressure of the monolayer waiting for the evaporation of the solvent is increased to 20 mN / m, and the electrode substrate is gently immersed at a speed of 5 mm / min across the water surface while keeping the pressure constant. Y-type monomolecular films were accumulated. By repeating this operation four times, a recording medium 1 having a recording layer 4a in which eight SOAZ layers are accumulated is created.

Example 2 A recording head provided with the probe electrode 1, the support 2, and a plurality of drive mechanisms 3 was prepared and fixed to the support mechanism 16 as shown in FIG. The support mechanism 16 is attached to the base 7 via at least three piezoelectric elements 14.

The piezoelectric elements 14 are individually driven by a piezoelectric element control circuit 13 controlled by the microcomputer 10. Voltage application and current detection circuit 1
0 applies a voltage to each probe electrode 2;
A current flowing between each probe electrode 1 and the recording medium 4 is detected. Other configurations are the same as those used in the first embodiment.

As in the first embodiment, the recording medium 4 having the recording layer 4a composed of eight SOAZ-LB films formed on the Au electrode 4b was fixed on the xyz fine movement device 5. xyz
The coarse movement device 6 and the xyz fine movement device 5 are driven to approach both with the bias of 100 mV applied between the probe electrode 2 and the Au electrode 4b. At this time, the piezoelectric element 14
Was adjusted so that all the probe electrodes approached the recording medium 4 uniformly, and all the probes were brought close to the state of the region a in FIG.

Under these conditions, the xyz fine movement device was controlled to measure the current flowing between each probe electrode 2 and the Au electrode 4b while driving the recording medium in the xy plane. It showed a current value of about 1 nA, and the fluctuation of the current flowing through each probe electrode during scanning was extremely small. Next, while driving the recording medium in the xy plane in the same manner as above, individual bit information (FIG.
Based on (a)), a write pulse train as shown in FIG. 7B was generated and added. Here, the first bit of the bit information is set as the bit corresponding to the ON state for all the individual bit information. After applying the pulse, the recording medium was driven again in the xy plane in the same manner as in writing, and the current flowing between the probe electrode 1 and the Au electrode 4b was measured under the condition of applying a bias of 100 mV. A change was obtained for each probe electrode, and a pulse train obtained by binarizing these current measurement values coincided with the individual bit information (FIG. 7A) applied to each probe electrode 2.

Next, an erase pulse train as shown in FIG. 7C was generated based on the individual bit information thus written. Here, it is assumed that the first bit of all the bit information remains ON and is not erased. The recording medium was driven in the xy plane in the same manner as in writing, the current value was measured, and the driving of the medium was temporarily stopped at the first bit, that is, at the position where the current value first changed by about four digits. At this time, all of the probe electrodes 2 are
About four orders of magnitude were observed. Subsequently, the drive of the medium was restarted, and in synchronization with this, an individual erase pulse train was applied to each of the previously generated probe electrodes 2.
Again, when the recording medium 1 was driven in the xy plane by the same method as in the writing, and the current was measured, all the bits except the first bit showed an OFF state, that is, a current value of about 1 nA, and it was confirmed that the erasing was completed. Was.

Instead of the erase pulse used here, of the bit information used for writing, except for the first bit,
An arbitrary pulse was selected to generate an erase pulse train (FIG. 7D), and an erase experiment was performed in the same manner as described above.
Erasure of only the selected bit was confirmed.

Further, as the operating conditions of the apparatus, the above-described recording, reproduction, and erasing were performed with a probe scanning range of 1 μm square and a scanning speed of 50 Hz / line. At this time, the high frequency cutoff frequency was set to 200 Hz using the output of the current detection circuit, and the probe electrode driving mechanism 3 was feedback-controlled by a frequency component of 200 Hz or less of the output. Under these operating conditions, no trouble occurred in reading data bits and the like. That is, under these conditions, the data bit has a spatial frequency of about 10 kHz, but it is considered that the microelastic body sufficiently followed the unevenness of the same level. The components used for the feedback control correspond to the swell corresponding to several cycles in the 1 μm region, and it is considered that all the probes sufficiently followed the swell or the inclination.

The variation in the tip positions of a plurality of probes could be absorbed by the driving of the probe electrode drive mechanism 3 respectively.

Example 3 The same recording, reproducing and erasing experiments as in Examples 1 and 2 were performed using a polyimide monomolecular accumulation film as the recording layer 4a. The method for forming the polyimide monomolecular cumulative film is described below.

[0058]

Embedded image

[0059]

Embedded image After dissolving the polyamic acid (molecular weight: about 200,000) shown in the formula (1) in an N, N-dimethylacetamide solvent (concentration in terms of monomer: 1 × 10 ⁻³ M), N, N-dimethylhexa separately adjusted was used. 1 × 10 ⁻³ M of decylamine in the same solvent
The solution was mixed at a ratio of 1: 2 (V / V) to prepare a polyamic acid hexadecylamine salt solution represented by the formula (2).
This solution was spread on an aqueous phase composed of pure water at a water temperature of 20 ° C. to form a monomolecular film on the water surface. After removing the solvent, the surface pressure was increased to 25.
The same electrode substrate as that used in Example 1 was gently immersed at a speed of 5 mm / min across the water surface while increasing the pressure to mN / m and keeping the surface pressure constant.
The film was gently pulled up at a rate of / min to form a two-layer Y-type monomolecular cumulative film. This operation was repeated six times to accumulate 12 monolayers. Next, this substrate was subjected to a heat treatment at 300 ° C. for 10 minutes to imidize polyamic acid hexadecylamine salt to obtain a polyimide single molecule cumulative film of formula (3).

[0060]

Embedded image The same recording, reproduction, and erasing as in Examples 1 and 2 could be performed on the recording medium 1 created as described above. . In the embodiments described above, the LB method has been used for forming the recording layer 101. However, any film forming method capable of forming an extremely thin and uniform film can be used without being limited to the LB method. Is a vacuum deposition method such as an MBE method or a CVD method.

Usable materials can be extended to other organic compounds including a π-electron conjugated system, as well as inorganic materials such as chalcogen compounds, as long as the materials can change the conductive state by applying a voltage.

Further, a semiconductor is used as a recording medium side electrode,
The electrode and the recording layer can be used integrally.

The present invention does not limit the substrate material, its shape and its surface structure at all.

On the other hand, the material of the probe electrode is applicable to the present invention as long as it has conductivity. Further, a wire, for example, a platinum wire, which is bent at 90 ° so as to also serve as a cantilever, can be used. S used as an elastic member
The iO ₂ cantilever is not limited to this, but may be of various shapes such as a double-supported beam or a thin film structure. Au, Ni, SUS, BeCu foil, etc. may be used as a material. In any case, it is necessary to displace by a small force.

Although the xyz fine movement device uses a cylindrical piezoelectric element, a tri-pot type piezoelectric element or a bimorph type piezoelectric element can also be used.

Although each of the above embodiments is a recording / reproducing apparatus, it may be a recording / reproducing apparatus.

[0067]

As described above, according to the present invention, the recording density is improved because the probe electrode is brought extremely close to the medium. Furthermore, the effect of irregularities on the recording medium surface on the read signal is reduced, and the signal ratio between the bit information write area and the non-write area is increased. And / or a playback device can be provided.

Also, during the operation of the apparatus, feedback control is performed on a signal which can be converted into the amount of deformation of the microelastic body by a component equal to or lower than the mechanical resonance frequency of the second elastic body, so that the medium can be controlled to have undulation or inclination. The probe electrode follows a large difference in height, and there is no trouble in reading data. Furthermore, it is possible to compensate for variations in probe tip positions when a plurality of probe electrodes are provided.

Further, since the microelastic body does not require feedback control, a high-speed feedback control circuit is not required, and the load on peripheral circuits is reduced particularly when a plurality of probes are provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a recording head of a recording and / or reproducing apparatus according to the present invention.

FIG. 2 is an explanatory diagram schematically illustrating a first recording and / or reproducing apparatus of the present invention.

FIG. 3 is a characteristic diagram showing a change in a current flowing between the probe electrode and a recording layer surface and a force acting between the two obtained when a distance between the probe electrode and the recording layer surface is changed.

FIG. 4 is a pulse voltage waveform for recording.

FIG. 5 is a pulse voltage waveform for erasing.

FIG. 6 is an explanatory diagram schematically showing a second recording and / or reproducing apparatus of the present invention.

FIG. 7 shows bit information, a recording pulse train, and an erasing pulse train given to one probe electrode in a recording, reproducing, and erasing experiment using a plurality of probe electrodes.

FIG. 8 shows M in which the recording layer used in the present invention is sandwiched between metal electrodes.
It is a structure schematic diagram of an IM element.

FIG. 9 shows current-voltage characteristics obtained with the device of FIG.

FIG. 10 is a current-voltage characteristic showing a memory effect obtained by the device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Probe electrode 1a Probe tip 1b Conductive coat 2 Probe electrode support 2a Micro elastic body 2b Second elastic body 3 Probe electrode driving mechanism 3a, 3a ', 3a "Electrode 3b, 3b' Piezoelectric thin film 4 Recording medium 4a Recording layer 4b Electrode 4c Substrate 5 xyz fine movement device 6 xyz coarse movement device 7 base 8 xyz fine movement device control circuit 9 xyz coarse movement device control circuit 10 microcomputer 11 current detection circuit 12 voltage application circuit 13 piezoelectric element control circuit 14 piezoelectric element 15 Probe electrode drive mechanism control circuit 16 Probe electrode support mechanism 17 Monomolecular accumulation film 18 Al electrode 19 Au electrode 20 Extraction electrode for current detection

────────────────────────────────────────────────── ─── Continuation of the front page (72) Kunihiro Sakai Inventor Canon Inc. (30) 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-2-98896 (JP, A) JP-A-5 -18741 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 9/00 G01N 37/00

Claims (21)

(57) [Claims] 1. A plurality of probes for reading and / or inputting information on an object , and each probe is supported.
Each comprising a plurality of independent supports,
Of the support, a first elastic body one probe is provided, has a lower resonant frequency than the first elastic member and a drive for changing the distance between the <br/> probe and the object A probe structure having a structure in which a second elastic body having a function is joined. 2. A method according to claim 1, wherein the plurality of recording media are arranged opposite to each other.
Probes and independent of each other supporting each probe
Consisting of a plurality of supports, each passing through a probe
An apparatus for recording information on an information recording medium, comprising:
Support people may have and before a first elastic body one probe is provided, the lower resonant frequency than the first elastic body
Recording apparatus characterized by having a structure obtained by bonding a second elastic body having a driving function for changing the distance between the serial probe and the information recording medium. 3. An apparatus for recording information on an information recording medium via a probe, wherein a support for supporting the probe has a small elastic body provided with the probe and a resonance frequency lower than the small elastic body. And has a structure in which a second elastic body having a drive mechanism for changing the distance between the probe and the information recording medium is joined, and the micro elastic body is disposed between the probe and the information recording medium. The probe and the information recording medium are arranged so that a force for deforming in the direction to correct the fluctuation acts between the probe and the information recording medium, and further, the deformation of the microelastic body does not always exceed a predetermined value. By controlling the probe-information recording medium interval by deforming the second elastic body by the driving mechanism in the direction to correct the voltage, applying a voltage between the probe-information recording medium in the control state A recording device for recording information by using a recording device. 4. A recording apparatus according to claim 3, characterized by using an atomic repulsion between the probe and information recording medium as a force acting between the probe and information recording medium. Wherein said probe there is a plurality, each according to any one of claims 3 or 4, characterized in that it is supported by the support recording apparatus. 6. There <br/> deviation of claims 3 to 5, characterized in that the recording by Rukoto alter the electrical characteristics of the information recording medium by applying a voltage between said probe information recording medium a recording apparatus according to an item or. 7. to claim 3, characterized in that the amount of deformation of the second elastic body is feedback-controlled by the amount of deformation, or signals which can be converted into deformation amount of the fine elastic bodies of the micro elastic body recording apparatus according to any one of 6. 8. A plurality of probes arranged to face an object.
And a plurality of independent probes supporting each probe.
Consists of a support, a device for detecting information from the object through the respective probes, the support of the each of the first elastic body one probe is provided, of the first information detecting apparatus characterized by having a structure obtained by bonding a second elastic body having a driving function for changing the distance between a and the probe and the object a lower resonant frequency than the elastic member . 9. A plurality of recording media arranged opposite to an information recording medium.
Probes and independent of each other supporting each probe
Consisting of a plurality of supports, each passing through a probe
An apparatus for reproducing information recorded on an information recording medium.
Te, support of the each of the first elastic body one probe is provided, has a lower resonant frequency than the first elastic body and for changing the distance between the probe and the information recording medium A reproducing apparatus having a structure in which a second elastic body having a driving function is joined. 10. An apparatus for reproducing information through a probe from the information recording medium, a support for supporting the probe, the probe lower resonant frequency than the fine elastic bodies and fine small elastic body provided with And has a structure in which a second elastic body having a drive mechanism for changing the distance between the probe and the information recording medium is joined, and the micro elastic body is disposed between the probe and the information recording medium. The probe and the information recording medium are arranged so that a force for deforming in the direction to correct the fluctuation acts between the probe and the information recording medium, and further, the deformation of the microelastic body does not always exceed a predetermined value. The distance between the probe and the information recording medium is controlled by deforming the second elastic body by the driving mechanism in a direction in which the probe and the information recording medium are corrected. A reproducing apparatus characterized by performing reproduction by outputting. 11. The reproducing apparatus according to claim 10, wherein an interatomic repulsion between the probe and the information recording medium is used as the force acting between the probe and the information recording medium. 12. The method of claim 11, wherein the probe there is a plurality, claim 10, characterized in that each is supported by said support
Or reproducing apparatus according to any one of 11. 13. A current between the probe and the information recording medium.
Reproducing apparatus according to any one of claims 9 to 12, characterized in that for reproducing the information by detecting the electrical characteristics of the information recording medium by the detection. 14. to claim 10, characterized in that the amount of deformation of the second elastic body is feedback-controlled by the amount of deformation, or signals which can be converted into deformation amount of the fine elastic bodies of the micro elastic body reproducing apparatus according to any one of 13. 15. A multi-function device arranged to face an information recording medium.
Number of probes and independent of each other supporting each probe
Composed of a plurality of supports, and through each probe
The information is recorded on the information recording medium, and the information is recorded on the information recording medium.
An apparatus for reproducing recorded information, supported <br/> lifting body of the each of the first elastic body one probe is provided,
The structure obtained by bonding a second elastic body having a driving function for changing the distance between a and the professional <br/> over blanking the information recording medium a lower resonant frequency than the first elastic body A recording / reproducing device, comprising: 16. An apparatus for recording and reproducing information through a probe in the information recording medium, a support for supporting the probe, micro elastic probe is provided with fine small elastic lower resonance A structure in which a second elastic body having a frequency and having a drive mechanism for changing a distance between the probe and the information recording medium is joined to the probe and the information recording medium; The probe / information recording medium is arranged so that a force for deforming in the direction for correcting the interval variation acts between the probe / information recording medium, and the deformation of the microelastic body does not always exceed a predetermined value. The second elastic body is deformed by the drive mechanism in a direction to correct the deformation so as to control the probe-information recording medium interval.
Information of a voltage between the recording medium is applied performs recording of information, recording and reproducing apparatus characterized by performing reproduction by detecting the current between before <br/> Symbol probe information recording medium. 17. A recording and reproducing apparatus according to claim 1 6, wherein the use of atomic repulsion between the probe and information recording medium as a force acting between the probe and information recording medium. 18. The method of claim 17, wherein the probe there is a plurality, claim 16, characterized in that each of which is supported by said support
Or reproducing apparatus according to any one of 17. 19. The method of claim 15 to 1 and performing recording by Rukoto alter the electrical characteristics of the information recording medium by applying a voltage between said probe information recording medium
The recording / reproducing apparatus according to any one of claims 8 to 13. 20. The method of claim 15 乃, characterized in that for reproducing the information by detecting the electrical characteristics of the information recording medium by the current detection between the probe information recording medium
Recording reproducing apparatus according to any one of Itaru 18. 21. to claim 16, characterized in that the amount of deformation of the second elastic body is feedback-controlled by the amount of deformation, or signals which can be converted into deformation amount of the fine elastic bodies of the micro elastic body recording reproducing apparatus according to any one of 20.