JPH09219043A - Recording and reproducing device and recording and reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to execute a large capacity of recording and reproducing at a low error rate by constituting part or the whole of a recording medium of a flat planar gold single crystal. SOLUTION: The flat planar gold single crystal precipitated from the gold complex soln. in used as the recording medium 4. The front end of a probe 1 is brought near to the recording medium 4 by a Z-axis driving device 13. When both approach in extreme proximity, the tunnel current flowing according to the distance between both is measured by a detecting circuit 18. The driving device 13 is so controlled by a servo circuit 11 that the flowing tunnel current attains a prescribed value, by which the spacing between the probe 1 and the recording medium 4 is controlled. Next, an electric field is impressed between the front end of the probe 1 and the surface of the recording medium 4 by a recording voltage impressing device 14, by which the Au of the material of the probe 1 is evaporated by the electric field from the front end of the probe 1 and is supplied. A very small projecting structure 15 (recording bit) consisting of the material supplied onto the recording medium is thus formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supplies a substance from the probe to the recording medium to record information by applying an electric field between the probe and the recording medium. The present invention relates to a recording / reproducing apparatus and a recording / reproducing method capable of large-capacity recording / reproduction in which information is reproduced by reading information by scanning.

[0002]

2. Description of the Related Art Currently, Scanning Probe
Applying the principle of Microscope (hereinafter SPM),
A method and an apparatus for forming a minute structure on the sample surface by utilizing the interaction between the probe and the sample surface have been developed.
Among them, a method has been proposed in which an electric field is applied between the probe and the sample surface to supply a substance from the tip of the probe to form a minute structure on the sample surface (US Pat. No. 5,043). , 5
No. 78). According to this method, 10
An extremely minute structure having a size of nm or less can be formed, and application to a large capacity recording technique is considered by using this minute structure as a recording bit as well as application to a circuit element or a mask. In this method, as a sample, a smooth surface formed by melting a gold wire to form facets of (111) plane, or a gold thin film grown on a mica substrate was used.

[0003]

However, the above-mentioned prior art has the following problems. The width of the smooth surface obtained by melting the gold wire is 150 nm.
It is about × 150 nm, and the number of minute structures that can be formed on a single smooth surface is limited. Moreover, since this smooth surface is formed on a spherical surface obtained by melting a gold wire, it is difficult to align the probe and the smooth surface, and it is possible to record a large amount of data by making the smooth surface plural. It is very difficult, and when a smooth surface obtained by melting this gold wire is used as a recording medium, the recording capacity is limited. The gold thin film grown on the mica substrate is composed of a large number of crystal grains. Therefore, a single continuous smooth surface is several μm ×
It is about several μm, and there are irregular grooves between each smooth surface, and when a large amount of recording is attempted by forming a large number of continuous minute structures to form a bit string, the smooth surface Due to the irregular groove between them, the bit string was divided and irregular bit loss occurred. Therefore, when the gold thin film grown on the mica substrate is used as a recording medium in the application to the large-capacity recording technique, many errors occur. Further, the mica substrate is a natural product and has a large variation in characteristics, and the substrate has irregular undulations and thus has low flatness. When recording and reproducing are performed on a gold thin film formed on such a substrate using a plurality of probes (Japanese Patent Laid-Open No. 04-321955), it is difficult to align the probes with a smooth surface, It is very difficult to perform capacity recording, and for this reason also, there is a limit in recording capacity when a gold thin film grown on a mica substrate is used as a recording medium.

Therefore, the present invention solves the above-mentioned problems in the prior art, and a recording medium having a single continuous smooth surface of gold, in which a large number of recording bits having a minute structure are hard to be oxidized by the surrounding environment. A recording / reproducing apparatus and a recording / reproducing method which are formed on the above and enable large-capacity recording / reproducing at a low error rate.

[0005]

In order to solve the above-mentioned problems, the present invention comprises a recording / reproducing apparatus and a recording / reproducing method as follows. That is, the recording / reproducing apparatus of the present invention includes a recording medium, a conductive probe, and voltage applying means for applying an electric field between the probe and the recording medium, and performs recording / reproducing of information. In the apparatus, a part or the whole of the recording medium is composed of a flat gold single crystal. Further, in the recording / reproducing apparatus of the present invention, the recording medium is preferably constituted by forming a flat gold single crystal on the conductive substrate, and the flat gold single crystal is gold. It can be formed by decomposing a gold complex in a complex aqueous solution. In the recording / reproducing device of the present invention,
The probe may have a multi-layered structure having a conductor layer on the surface thereof, or may have a plurality of integrated structures. Further, in the recording / reproducing apparatus of the present invention, an acceleration electrode may be provided between the probe and the recording medium. Further, in the recording / reproducing method of the present invention, by applying an electric field between the probe and the recording medium, a substance is supplied from the probe onto the recording medium to record information, and the probe is scanned. In the recording / reproducing method for reproducing information by reading the information by the method, a part or the whole of the recording medium is composed of a flat gold single crystal, and the information is recorded or reproduced. In the recording / reproducing method of the present invention, the recording / reproducing means records the information by locally changing the shape of the recording medium surface, and reproduces the information by reading the shape of the recording medium surface. The configuration can be adopted. In the recording / reproducing method of the present invention, as the recording / reproducing means, the information is recorded by locally changing the conductivity of the surface of the recording medium, and the information is reproduced by reading the conductivity of the surface of the recording medium. The configuration can be adopted by

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, since the recording medium is made of a flat gold single crystal as described above, a large number of recording bits having a minute structure can be formed by using a gold single crystal that is not easily oxidized by the surrounding environment. Since it can be formed on a recording medium having one continuous smooth surface, large-capacity recording / reproduction can be realized at a low error rate. Next, the contents of the recording / reproducing apparatus of the present invention will be described in detail. As described above, the recording / reproducing apparatus of the present invention is a recording / reproducing apparatus including a recording medium, a conductive probe, and means for applying an electric field between the probe and the recording medium. Although the medium is made of a flat gold single crystal, SPM can be applied to the recording / reproducing apparatus of the present invention. SPM that can be used by applying to the recording / reproducing apparatus of the present invention
Can be any as long as it can measure the shape of the object surface or the conductivity by scanning the probe. As a typical example, a scanning tunneling microscope (Scanning Tunneling Micro) is used.
Scope: STM, atomic force microscope (Atom)
icForce Microscope: AFM)
Etc. can be used. In the recording / reproducing apparatus of the present invention, the flat gold single crystal is used as the recording medium as described above. This flat gold single crystal is produced, for example, as follows (Japanese Patent Laid-Open No. 5-201793). The substrate is put into a solution containing a gold iodide complex, a bromide complex, a chloride complex, and the like, and the solution temperature is 30 ° C to 1 ° C.
The solution is maintained at 00 ° C. and evaporated, and the solution is transferred to a supersaturated state to grow a flat gold single crystal group on the substrate.
By doing this, the particle diameter in the in-plane direction of the substrate is 2 m.
It is possible to obtain a flat gold single crystal having a size of about m or more. Further, in the flat gold single crystal thus produced, even when the optical observation by the phase contrast microscope and the surface observation by the STM and AFM are performed, one step generated during the crystal growth process corresponds to one atomic layer. Only a few steps are observed, and no further large steps, holes, grooves, etc. are observed, and it has very high smoothness. Thus, a continuous smooth surface having an extremely large area can be obtained as compared with the conventional example.

The flat gold single crystal used as the recording medium is
The gold single crystal can be used alone, but is preferably formed on a conductive substrate before use. By doing so, wiring for applying a voltage to the recording medium can be easily formed, and an electric field can be easily applied between the recording medium and the probe. As the conductive substrate, a substrate on which an electrode layer is formed can be used. It is preferable to use a substrate having no waviness and high flatness, and a plate such as single crystal silicon or quartz is preferable. As the electrode layer, it is preferable to use a metal that does not dissolve in the solution when the flat gold single crystal is grown, and Ti, Cr and the like are particularly preferable.

For the probe used in the recording / reproducing apparatus of the present invention, the shape and material can be selected according to the type of SPM used. However, since the probe needs to have electrical conductivity in order to apply an electric field between it and the recording medium, either the entire probe is made of a conductive substance, or the probe is made of a semiconductor material or an insulator material. In this case, a conductor layer made of a conductive substance is provided on the surface as a multilayer structure. Au, Ga, W, Pt and the like are preferable as the conductive material. Further, an acceleration electrode for extraction may be provided between the probe and the recording medium, if necessary. As the accelerating electrode, a thin plate-shaped one made of a conductive substance and having minute holes is used. When recording, the tip of the probe is brought close to the center of this hole and the probe and the acceleration electrode are fixed to each other. Moreover, a plurality of probes can be used by accumulating them. The integrated probe can be formed on the substrate by using a photolithography technique or the like.

The recording method of the present invention will be described below.
By applying an electric field between the tip of the probe and the recording medium in a state where the tip of the probe is brought close to the surface of the recording medium, a substance is supplied from the probe onto the recording medium to obtain an arbitrary recorded bit. Information is recorded by forming a minute structure. In the present invention, by depositing the substance supplied from the probe on the recording medium, a minute convex structure that becomes an arbitrary recording bit is formed. Alternatively, in the same manner, the surface of the recording medium is locally etched by the substance supplied from the tip of the probe to form a minute concave structure which becomes an arbitrary recording bit. To form a minute structure to be a recording bit, depending on the material of the probe, a pulsed electric field with a width of several hundred nanoseconds to several hundred microseconds is used as the probe. Apply between recording media. Whether to deposit or etch can be controlled by the polarity of the applied electric field and the pulse conditions. Further, in the present invention, by relatively scanning the probe and the recording medium, by applying an electric field between the probe and the recording medium while controlling the relative position,
Recording can be performed by forming a minute structure which becomes a recording bit of an arbitrary shape in an arbitrary place. Further, in the present invention, information is reproduced by reading the recording bit with the probe. Information is read out by scanning the probe with the tip of the probe brought close to the surface of the recording medium, detecting the presence or absence of a minute structure serving as a recording bit.

In the recording / reproducing method of the present invention, information is recorded by forming a minute structure which becomes a recording bit and locally changing the shape of the surface of the recording medium to reproduce the information on the surface of the recording medium. It can be done by reading the shape. Further, in the recording / reproducing method of the present invention, information is recorded by forming a minute structure to be a recording bit and locally changing the conductivity of the surface of the recording medium,
Information can be reproduced by reading the conductivity of the surface of the recording medium. When recording / reproducing is performed in this manner, Ga, W, Pt are used as the conductive substance forming the probe.
And the like are used to form a minute structure made of a material different from that of the recording medium on the recording medium.

[0011]

Embodiments of the present invention will be described below. [Embodiment 1] FIG. 1 shows a schematic view of a recording / reproducing apparatus of Embodiment 1. In this embodiment, STM which is one of SPM is applied and used. In FIG. 1, 1 probe, 4 is a recording medium, 5
Is a substrate, 6 is a lower electrode layer, 7 is an XY stage, 11 is a servo circuit, 12 is an XY drive control device, 13 is a Z-axis drive device, 14 is a recording voltage applying device, and 15 is a convex structure (recording). Bit), 16 is a concave structure (recording bit), 17 is a control computer, and 18 is a tunnel current detection circuit. Further, the servo circuit 11, the XY drive control device 12, the recording voltage application device 14, and the tunnel current detection circuit 18 are all connected to and controlled by the control computer 17.

As the recording medium 4 of the apparatus of this embodiment, a flat gold single crystal deposited from a gold complex solution was used. The flat gold single crystal is produced as follows. After potassium iodide and iodine were added to distilled water to prepare an iodine aqueous solution, gold was added and dissolved by stirring to prepare an aqueous solution containing a gold iodide complex. Next, the substrate 5 was placed in the aqueous solution. A single crystal silicon substrate was used as the base body 5, and a conductive substrate having 100 nm of Ti deposited thereon by the sputtering method as the electrode layer 6 was used. Next, the temperature of the aqueous solution was maintained at 80 ° C. to promote the volatilization of the iodine component.

By doing so, the aqueous solution containing the gold iodide complex was transferred to a supersaturated state to decompose the gold iodide complex and grow the flat gold single crystal group on the substrate 5. . Thus, a flat gold single crystal having a grain size of 2 mm or more in the in-plane direction of the substrate 5 was obtained. Further, the flat gold single crystal thus produced was optically observed by a phase contrast microscope and the surface was observed by STM and AFM. As a result, one step generated during the crystal growth process corresponds to one atomic layer. Only a few steps were observed, and there were no large steps, holes, or grooves, and it had very high smoothness. In this way, a very smooth, smooth surface of gold was obtained, which was not easily oxidized by the surrounding environment. Further, the probe 1 of the apparatus of the present embodiment is
The material is made of Au and is manufactured by mechanical polishing and electrolytic polishing so as to have a sharp tip.

A recording method using the recording / reproducing apparatus of this embodiment will be described below. First, the tip of the probe 1 was brought close to the surface of the recording medium 4 by the Z-axis drive device 13. At this time, the space between the probe 1 and the recording medium 4 was controlled as follows. When the surface of the recording medium 4 and the tip of the probe 1 are very close to each other, the tunnel current flowing according to the distance between them is measured using the tunnel current detecting circuit 18, and the tunnel current flowing by the servo circuit 11 is set to a predetermined value. The Z-axis driving device 13 was controlled so as to obtain the value, and the distance between the probe 1 and the recording medium 4 was controlled. Next, an electric field is applied between the tip of the probe 1 and the surface of the recording medium 4 by the recording voltage applying device 14, and Au, which is the material of the probe 1, is field-evaporated and supplied from the tip of the probe 1. As a result, a minute convex structure 15 (recording bit) made of the supplied substance was formed on the recording medium 4. Alternatively, in the same manner, the surface of the recording medium 4 is locally etched by the substance supplied from the tip of the probe 1 to form the concave structure 1
6 (recording bits) were formed.

In the present embodiment, as an example, the convex structure 15 is formed by applying a pulsed electric field of 2 V for 10 microseconds with the probe side at −, and similarly, the probe side is set at −.
The concave structure 16 could be formed by applying a pulsed electric field of 5 V for 10 microseconds. In addition, the recording medium 4
The XY stage 7 on which is mounted is scanned in the XY direction by the XY drive control device 12 to control the relative position of the probe 1 and the recording medium 4, and the electric field between the probe 1 and the recording medium 4 is controlled. By applying, it was possible to form a minute convex structure 15 or concave structure 16 having an arbitrary shape at an arbitrary position for recording. As described above, according to the present embodiment, it is possible to record information by forming a minute structure serving as a recording bit and locally changing the shape of the recording medium surface.

An information reproducing method using the recording / reproducing apparatus of this embodiment will be described below. The probe 1 is brought close to the recording medium 4, and the tunnel current flowing between the probe 1 and the recording medium 4 is monitored by the tunnel current detecting circuit 18, while the recording medium 4 is mounted on the X-.
The Y stage 7 is moved to XY by the XY drive controller 12.
Direction, so that the tunnel current corresponding to the unevenness on the recording medium 4 has a predetermined constant value.
3 is controlled, and the servo amount of the control at this time is measured to measure the shape of the surface of the recording medium 4 to obtain a surface image, and the presence or absence of the convex structure 15 or the concave structure 16 which is a recording bit is detected. Information was read out.

As described above, according to this embodiment, the information can be reproduced by reading the shape of the surface of the recording medium. When recording / reproducing was performed as described above, according to the recording / reproducing apparatus and the recording / reproducing method of the present embodiment, a large number of recording bits having a minute structure of the order of nm were oxidized by the surrounding environment. It could be formed on a single continuous smooth surface of hard gold. In these many recorded bits, no bit loss was found in the bit string.
As described above, according to the present embodiment, it is possible to provide a recording / reproducing apparatus and a recording / reproducing method that enable large-capacity recording / reproduction with a low error rate.

[Embodiment 2] FIG. 2 is a schematic view of a recording / reproducing apparatus of Embodiment 2. In this embodiment, STM which is one of SPM is applied and used. In FIG. 2, 1 probe, 4 is a recording medium, 5 is a substrate, 6 is an electrode layer, 7 is an XY stage, 11 is a servo circuit, 12 is an XY drive control device, 1
3 is a Z-axis driving device, 14 is a recording voltage applying device, 15 is a convex structure (recording bit), 17 is a control computer, 18
Is a tunnel current detection circuit. Also, the servo circuit 1
1, an XY drive control device 12, a recording voltage application device 14,
All the tunnel current detection circuits 18 are connected to and controlled by the control computer 17. As the recording medium 4 of the apparatus of this example, a flat gold single crystal produced on a conductive substrate in which the electrode layer 6 was provided on the substrate 5 in the same manner as in Example 1 was used. Further, the probe 1 of the apparatus of this embodiment is made of W as a material and is manufactured by mechanical polishing and electrolytic polishing so as to have a sharp tip.

A recording method using the recording / reproducing apparatus of this embodiment will be described below. First, the tip of the probe 1 was brought close to the surface of the recording medium 4 by the Z-axis drive device 13. At this time, the gap between the probe 1 and the recording medium 4 was controlled in the same manner as in Example 1. Next, an electric field is applied between the tip of the probe 1 and the surface of the recording medium 4 by the recording voltage applying device 14, and W, which is the material of the probe 1, is field-evaporated and supplied from the tip of the probe 1. As a result, a minute convex structure 15 (recording bit) made of the supplied substance was formed on the recording medium 4. In this example, as an example, the convex structure 15 could be formed by applying a pulsed electric field of 5 V for 10 μsec with the probe side to − between the probe 1 and the recording medium 4.
Further, the XY stage 7 on which the recording medium 4 is placed is scanned in the XY directions by the XY drive control device 12 to control the relative positions of the probe 1 and the recording medium 4, and the probe 1 and the recording medium 4. By applying an electric field between No. 4 and No. 4, a minute convex structure 15 having an arbitrary shape was formed at an arbitrary position, and recording could be performed. As described above, according to the present embodiment, information is recorded by supplying W having a conductivity different from that of the recording medium onto the recording medium made of a flat gold single crystal to form a minute structure to be a recording bit. I was able to.

A method of reproducing information using the recording / reproducing apparatus of this embodiment will be described below. The probe 1 is brought close to the recording medium 4, and the tunnel current flowing between the probe 1 and the recording medium 4 is monitored by the tunnel current detecting circuit 18, while the recording medium 4 is mounted on the X-.
The Y stage 7 is moved to XY by the XY drive controller 12.
Direction, the conductivity of the surface of the recording medium 4 was measured to obtain a surface image, and the presence or absence of the convex structure 15 as a recording bit was detected to read information. As described above, according to the present embodiment, information can be reproduced by reading the conductivity of the surface of the recording medium.

When recording / reproducing was performed as described above, according to the recording / reproducing apparatus and the recording / reproducing method of the present embodiment, a large number of recording bits having a minute structure of the order of nm were recorded in the surrounding environment. It could be formed on a single continuous smooth surface of gold, which is not easily oxidized by. In these many recorded bits, no bit loss was found in the bit string. As described above, according to the present embodiment, it is possible to provide a recording / reproducing apparatus and a recording / reproducing method that enable large-capacity recording / reproducing at a low error rate.

[Third Embodiment] FIG. 3 is a schematic diagram of a recording / reproducing apparatus according to a third embodiment. In this embodiment, an STM, which is a type of SPM, is applied and used, and an accelerating electrode is provided between the probe and the recording medium. In FIG. 3, 1 is a probe,
4 is a recording medium, 5 is a substrate, 6 is an electrode layer, 7 is an XY stage, 11 is a servo circuit, 12 is an XY drive control device,
13 is a Z-axis driving device, 14 is a recording voltage applying device, 15 is a convex structure (recording bit), 16 is a concave structure (recording bit),
Reference numeral 17 is a control computer, 18 is a tunnel current detection circuit, 19 is an accelerating electrode, and 20 is an accelerating voltage applying device.
Further, the servo circuit 11, the XY drive control device 12, the recording voltage application device 14, the tunnel current detection circuit 18, and the acceleration voltage application device 20 are all connected to the control computer 17 so as to be controlled.

As the recording medium 4 of the apparatus of this example, a flat gold single crystal prepared on a conductive substrate having an electrode layer 6 on a substrate 5 was used as in Example 1. Further, the probe 1 of the apparatus of this embodiment is made of Pt as a material and is manufactured by mechanical polishing and electrolytic polishing so as to have a sharp tip. As the accelerating electrode 19 of the apparatus of this embodiment, a silicon single crystal substrate having a high conductivity was thinly processed, and a circular hole having a diameter of 0.5 μm was formed by a photolithography technique. At the time of recording, the tip of the probe 1 was brought close to the center of this hole, and the probe 1 and the acceleration electrode 19 were fixed to each other.

A recording method using the recording / reproducing apparatus of this embodiment will be described below. First, the tip of the probe 1 and the acceleration electrode 19 were brought close to the surface of the recording medium 4 by the Z-axis drive device 13. At this time, the gap between the probe 1 and the recording medium 4 was controlled in the same manner as in Example 1.

Next, an electric field is applied between the tip of the probe 1 and the surface of the recording medium 4 by the recording voltage application device 14, and at the same time, the tip of the probe 1 and the acceleration electrode 19 are applied by using the acceleration voltage application circuit 20. An accelerating voltage was applied in between. By doing so, Pt, which is the material of the probe 1, is field-evaporated from the tip of the probe 1, and further accelerated by the accelerating electrode 19 to be supplied. The minute convex structure 15 (recording bit) was formed. Alternatively, in the same manner, the material supplied from the tip of the probe 1 causes the recording medium 4
The surface was locally etched to form the concave structure 16 (recording bit). In this embodiment, as an example, 5 V is set between the tip of the probe 1 and the acceleration electrode 19 with the probe side being +.
The convex structure 15 was formed by applying a pulsed electric field of 2 V for 10 microseconds with the probe side to − between the probe 1 and the recording medium 4 while applying the accelerating voltage. Further, the concave structure 16 could be formed by reversing the polarity of the acceleration voltage and then applying the same pulsed electric field between the probe 1 and the recording medium 4. Further, the XY stage 7 on which the recording medium 4 is placed is scanned in the XY directions by the XY drive control device 12 to control the relative positions of the probe 1 and the recording medium 4, and the probe 1 and the recording medium 4. By applying an electric field to question 4,
Recording could be performed by forming a minute convex structure 15 or concave structure 16 having an arbitrary shape at an arbitrary location.

As a method of reproducing information using the recording / reproducing apparatus of this embodiment, the acceleration electrode 19 is removed and the first embodiment is used.
In the same manner as above, information could be reproduced by reading the shape of the recording medium surface. When recording / reproducing was performed as described above, according to the recording / reproducing apparatus and the recording / reproducing method of the present embodiment, a large number of recording bits having a minute structure of the order of nm were oxidized by the surrounding environment. It could be formed on a single continuous smooth surface of hard gold. In these many recorded bits, no bit loss was found in the bit string. As described above, according to the present embodiment, it is possible to provide a recording / reproducing apparatus and a recording / reproducing method that enable large-capacity recording / reproducing at a low error rate.

[Embodiment 4] FIG. 4 shows a schematic diagram of a recording / reproducing apparatus of Embodiment 4. In this embodiment, an AFM, which is one type of SPM, is applied and used. In FIG. 4, 1 is a probe, 2
Is a cantilever, 3 is a conductor layer, 4 is a recording medium, 5 is a substrate, 6 is an electrode layer, 7 is an XY stage, 8 is a semiconductor laser, 9 is a four-division photodiode, 10 is a displacement detection system, 11 is Servo circuit, 12 is an XY drive controller, 1
3 is a Z-axis driving device, 14 is a recording voltage applying device, 15 is a convex structure (recording bit), 16 is a concave structure (recording bit), 1
Reference numeral 7 is a control computer. Also, the displacement detection system 1
0, the servo circuit 11, the XY drive control device 12, and the recording voltage application device 14 are all connected to and controlled by the control computer 17. As the recording medium 4 of the apparatus of this example, a flat gold single crystal produced on a conductive substrate in which the electrode layer 6 was provided on the substrate 5 in the same manner as in Example 1 was used. The probe 1 of the apparatus of this embodiment is formed on the free end of the cantilever 2. The probe 1 is integrally formed with the cantilever 2 and is made of Si3N4 which is an insulating material. A on both sides of the probe 1 and cantilever 2
The conductor layer 3 was formed by depositing 100 nm of u by the sputtering method.

A recording method using the recording / reproducing apparatus of this embodiment will be described below. First, the tip of the probe 1 having the conductor layer 3 was brought close to the surface of the recording medium 4 by the Z-axis drive device 13. At this time, the space between the probe 1 and the recording medium 4 was controlled as follows. The deflection of the cantilever 2 caused by the force generated according to the distance between the recording medium 4 and the tip of the probe 1 when they are very close to each other is used by using the semiconductor laser 8, the four-division photodiode 9, and the displacement detection system 10. The Z-axis drive device 13 was measured by the servo circuit 11 so that the deflection of the cantilever 2 was a predetermined value, and the distance between the probe 1 and the recording medium 4 was controlled. Next, in the same manner as in Example 1, an electric field is applied between the tip of the probe 1 and the surface of the recording medium 4 by the recording voltage applying device 14, and the minute convex structure 15 (recording bit) and the concave structure 16 are formed.
(Record bit) formed. The conditions of the applied electric field were the same as in Example 1. Further, the XY stage 7 on which the recording medium 4 is placed is scanned in the XY directions by the XY drive control device 12 to control the relative positions of the probe 1 and the recording medium 4, and the probe 1 and the recording medium 4. By applying an electric field between No. 4 and No. 4, it was possible to form a minute convex structure 15 or concave structure 16 having an arbitrary shape at an arbitrary position for recording. As described above, according to the present embodiment, it is possible to record information by forming a minute structure serving as a recording bit and locally changing the shape of the recording medium surface.

A method of reproducing information using the recording / reproducing apparatus of this embodiment will be described below. After the probe 1 is brought close to the recording medium 4, the XY stage 7 on which the recording medium 4 is placed is moved to the X-
The cantilever 2 generated by the unevenness on the recording medium 4 is scanned in the XY direction by the Y drive control device 12.
The deflection of the cantilever 2 is measured by using the semiconductor laser 8, the 4-division photodiode 9, and the displacement detection system 10, and the servo circuit 11 controls the Z-axis drive device 13 so that the deflection of the cantilever 2 becomes a predetermined constant value. The shape of the surface of the recording medium 4 is measured to obtain a surface image by measuring the servo amount of the control at the time, and the presence or absence of the convex structure 15 or the concave structure 16 which is a recording bit is detected to read information. It was As described above, according to this embodiment, the information can be reproduced by reading the shape of the surface of the recording medium.

When recording / reproducing was performed as described above, according to the recording / reproducing apparatus and the recording / reproducing method of the present embodiment, a large number of recording bits having a minute structure with a size of nm order were recorded in the surrounding environment. It could be formed on a single continuous smooth surface of gold, which is not easily oxidized by. In these many recorded bits, no bit loss was found in the bit string. As described above, according to the present embodiment, it is possible to provide a recording / reproducing apparatus and a recording / reproducing method that enable large-capacity recording / reproducing at a low error rate.

[Embodiment 5] FIG. 5 shows a schematic view of a recording / reproducing apparatus of Embodiment 5. In this embodiment, an AFM, which is one type of SPM, is applied and used. Furthermore, in this embodiment,
A plurality of probes were accumulated and used. In FIG. 5, 1 is a probe, 2 is a cantilever, 3 is a conductor layer, 4 is a recording medium,
5 is a substrate, 6 is an electrode layer, 15 is a convex structure (recording bit),
Reference numeral 16 is a concave structure (recording bit), and 21 is a probe substrate.
An XY drive system including an XY stage and an XY drive control device similar to that in Example 4 was provided. For each probe, a semiconductor laser similar to that of the fourth embodiment,
A Z-axis drive system consisting of a split photodiode, displacement detection system, servo circuit, and Z-axis drive device was provided. Further, a recording voltage applying device was provided for each probe. These X-
The Y and Z axis drive systems and the recording voltage application device were all connected to and controlled by a control computer. As the recording medium 4 of the apparatus of this example, a flat gold single crystal produced on a conductive substrate in which the electrode layer 6 was provided on the substrate 5 in the same manner as in Example 1 was used.

The probe 1 of the apparatus of this embodiment is formed on the free end of the cantilever 2. The probe 1 is integrally formed with the cantilever 2, and the material is Si which is an insulator material.
3N4 was used. Further, Au is deposited to 100 nm on both surfaces of the probe 1 and the cantilever 2 by a sputtering method,
The conductor layer 3 was formed. These are formed by integrating a plurality of them on a probe substrate 21 made of silicon single crystal by using a photolithography technique. First, the plurality of probes 1 were aligned with the recording medium 4. In this embodiment, a flat gold single crystal having an extremely large area and having a continuous smooth surface is used as the recording medium, so that the substrate 5 on which the recording medium is placed and the probe substrate 21 are made to approach each other in parallel. The spacing between all of the probes 1 and the recording medium 4 was controlled within a desired range, so that the surfaces could be easily aligned. Subsequently, recording and reproduction were performed using a plurality of probes 1 in the same manner as in Example 4.

When recording / reproducing was performed as described above, according to the recording / reproducing apparatus and the recording / reproducing method of the present embodiment, a large number of recording bits having a minute structure of the order of nm were recorded in the surrounding environment. It could be formed on a single continuous smooth surface of gold, which is not easily oxidized by. In these many recorded bits, no bit loss was found in the bit string. Also, these recording / reproducing operations could be performed equally well with all the probes. As described above, according to the present embodiment, it is possible to provide a recording / reproducing apparatus and a recording / reproducing method that enable large-capacity recording / reproducing at a low error rate.

[0034]

As described above, according to the present invention, since the recording medium is composed of the flat plate-shaped gold single crystal as described above, a large number of recording bits having a minute structure can be formed by using a single gold layer which is not easily oxidized by the surrounding environment. A recording / reproducing apparatus and a recording / reproducing method capable of being formed on a recording medium having a continuous smooth surface and capable of performing large-capacity recording / reproduction at a low error rate can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a first embodiment of the present invention.

FIG. 2 is a diagram showing an outline of a second embodiment of the present invention.

FIG. 3 is a diagram showing an outline of a third embodiment of the present invention.

FIG. 4 is a diagram showing an outline of a fourth embodiment of the present invention.

FIG. 5 is a diagram showing an outline of a fifth embodiment of the present invention.

[Explanation of symbols]

 1: Probe 2: Cantilever 3: Conductor Layer 4: Recording Medium 5: Substrate 6: Electrode Layer 7: XY Stage 8: Semiconductor Laser 9: Quadrant Photodiode 10: Displacement Detection System 11: Servo Circuit 12: XY drive control device 13: Z-axis drive device 14: Recording voltage application device 15: Convex structure (recording bit) 16: Concave structure (recording bit) 17: Control computer 18: Tunnel current detection circuit 19: Accelerating electrode 20 : Accelerating voltage application device 21: Probe substrate

Claims (9)

[Claims] 1. A recording / reproducing apparatus for recording / reproducing information, comprising a recording medium, a conductive probe, and voltage applying means for applying an electric field between the probe and the recording medium. A recording / reproducing apparatus characterized in that a part or the whole of the medium is composed of a flat gold single crystal. 2. The recording / reproducing apparatus according to claim 1, wherein the recording medium is constituted by forming a flat gold single crystal on a conductive substrate thereof. 3. The recording / reproducing apparatus according to claim 1, wherein the flat gold single crystal is formed by decomposing a gold complex in a gold complex aqueous solution. . 4. The probe has a multi-layered structure and has a conductor layer on its surface.
The recording / reproducing device according to any one of the above items. Recording and reproducing device. 5. The recording / reproducing apparatus according to claim 1, wherein a plurality of the probes are integrated. 6. An accelerating electrode is provided between the probe and the recording medium.
The recording / reproducing device according to any one of the above items. 7. An information is recorded by supplying a substance from the probe onto the recording medium by applying an electric field between the probe and the recording medium, and reading the information by scanning the probe. A recording / reproducing method for reproducing information, characterized in that a part or the whole of the recording medium is composed of a flat gold single crystal to record or reproduce information. 8. The method according to claim 7, wherein the recording of the information is performed by locally changing the shape of the surface of the recording medium, and the reproduction of the information is performed by reading the shape of the surface of the recording medium. Recording and playback method. 9. The method according to claim 1, wherein the recording of the information is performed by locally changing the conductivity of the surface of the recording medium, and the reproduction of the information is performed by reading the conductivity of the surface of the recording medium. The recording / reproducing method according to item 7.