JPH04281237A - Recording medium, information processing device using the same, recording medium cassette - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an information processing device that performs processing such as recording, reproduction, or erasing by applying the technology of a scanning tunneling electron microscope (hereinafter referred to as "STM"), and a recording medium used therein. .

0002

BACKGROUND OF THE INVENTION In recent years, with the development of the information society, large-capacity memory technology has been developed. Recently, recording and reproducing devices using STM have appeared (for example, Japanese Patent Laid-Open No. 61
-89636, etc.). STM applies a voltage between a metal probe (tunnel tip) and a conductive material to
This takes advantage of the fact that a tunnel current flows when brought close to each other within a distance of about m. This tunnel current is sensitive to changes in the distance between the two. By scanning the probe electrode while keeping the tunneling current constant, it is possible to read various information regarding the total electron transport in real space. At this time, the resolution in the in-plane direction is about 0.1 nm. Therefore, by applying the principle of STM, it is possible to perform high-density recording and reproduction on the atomic order (sub-nanometer).

[0003] A method has also been proposed in which information written on a recording medium having a recording surface on a microdisk is read out using a tunnel current using an array of tunnel chips (Japanese Patent Application Laid-Open No. 281138/1983). In this method, recording and reproduction are performed using a probe having a tip on a cantilever for detecting a tunnel current.

[0004] Another proposal has been made to perform recording, reproducing, and erasing by detecting current such as tunnel current using a recording medium having an electric memory effect (Japanese Unexamined Patent Application Publication No. 1983-1999).
161552, 63-161553, etc.).

[0005]

SUMMARY OF THE INVENTION As mentioned above, STM is sensitive to changes in the distance (Z) between the probe and the conductive material. In a recording/reproducing device using a tunnel current, when a recording medium is loaded, the recording medium is initially loaded as far away as possible to prevent the probe from coming into contact with the surface of the recording medium during handling. Thereafter, the coarse movement mechanism brings the probe and the recording medium relatively close to each other. When the recording medium and the probe are brought relatively close to each other by the coarse movement mechanism, there is a risk that the recording layer or the probe may be damaged due to contact between the recording surface of the probe.

[0006]

[Means and operations for solving the problems] The present invention has been made to solve the above problems.

That is, in the present invention, a protrusion for adjusting the distance in the Z-axis direction (the distance between the probe and the recording medium) is provided on the substrate of the recording medium to avoid contact of the probe with the recording surface and to prevent the probe from contacting the recording surface. This makes it easier to install.

A first aspect of the present invention is a recording medium characterized in that it has a protrusion that surrounds a recording surface and forms a closed space,
The second is a first recording medium, a multi-probe having a plurality of probes, a means for applying a recording and/or erasing voltage to the recording medium, and a tunnel current flowing between the recording medium and the probes. and a means for detecting and reproducing field emission current;
A recording medium cassette characterized in that a first recording medium is placed in a container having a hood that can be opened and closed, and a contact electrode connected to an electrode of the recording medium is provided outside the container,
Fourth, a third recording medium cassette, a multi-probe having a plurality of probes, a mechanism for opening and closing the hood when the recording medium cassette is attached, and means for applying recording and/or erasing voltage to the recording medium. and means for detecting and reproducing a tunnel current or field emission current flowing between a recording medium and a probe.

[0009] The present invention will be explained in detail below with reference to the drawings, in which the same reference numerals are given to the parts common to each drawing.

FIG. 1 shows a schematic cross-sectional view of the first recording medium of the present invention in contact with a multi-probe, which is a probe support substrate having a plurality of probes. In FIG. 1, 1 is a probe head, 2 is a multi-probe, and 7 is a recording medium.
It consists of 3 substrates, 4 recording layers, 5 electrodes, and 6 protrusions. Reference numeral 8 denotes a sliding surface on which the protrusion 6 provided on the recording medium 7 comes into contact with the multi-probe 2 .

Further, FIG. 2 shows an enlarged sectional view of the multi-probe shown in FIG. 1. In FIG. 2, 10 is a probe, 11 is a cantilever that supports it, and 13 is an electrode for an electrostatic actuator.

As shown in FIG. 2, the multi-probe 2 has a probe head 1 in which probes 10 are formed on a cantilever, which are arranged two-dimensionally. This multi-probe 2 can be formed using micromechanics technology in the same manner as described in the above-mentioned Japanese Unexamined Patent Publication No. 62-281138. Further, these plurality of probe heads 1 do not exist on the entire surface of the multi-probe surface, but exist on a part of the multi-probe surface.

As shown in FIG. 1, the protrusion 6 is provided on a part of the substrate 2 to form a closed space surrounding the recording surface. Its shape is not particularly limited as long as it can control the distance between the multi-probe and the surface of the recording medium, but it is preferably a convex strip formed so as to surround the recording surface at a constant height. When bringing the probe close to each other using a coarse movement mechanism (not shown), the multi-probe surface is moved until it comes into contact with this protrusion 6 provided on the recording medium 7.
It becomes possible to quickly arrange the recording medium 7 in parallel to the multi-probe 2 up to the recording/reproducing position.

Furthermore, if the multi-probe surface has an area four times or more larger than the recording surface divided by the protrusions 6, the multi-probe 2 can be made two-dimensional even if the recording surface is much larger than the area where the probe head 1 exists. This allows for large and easy movements while maintaining a constant distance.

Furthermore, when the multi-probe 2 and the protrusions 6 are arranged in parallel, the recording surface is kept almost completely shielded from the outside air, so that the recording surface can be prevented from being damaged by dust adhesion. Can be done.

The protrusions 6 on the recording medium 7 can be formed to an arbitrary height by etching and patterning the electrodes or the substrate 3 using lithography on the substrate 3 used for the recording medium 7.
It can be formed in different widths and positions.

Furthermore, in the recording medium of the present invention, when an organic film formed by the Langmuir-Blodgett method (LB method) is used for the recording layer 4, the organic film is also applied to the sliding surface 8 on the protrusion 6. can be formed. In this case, the organic film acts as a lubricating protective film and facilitates relative movement between the multi-probe 2 and the recording medium 7, which is preferable. More preferably, if a polymer film such as polyimide is used, the durability of the sliding surface 8 can be improved. Furthermore, using a polyimide polymer film containing fluorine atoms improves sliding properties.
Favorable results are obtained. Regarding the formation of polyimide film by LB method, please refer to Polymer Journal
Volume 20 p. 269 (1988).

In FIG. 2, a voltage is applied to the probe 10 for detecting a tunnel current or recording it in a recording layer, and its movement in the Z direction is controlled by a cantilever 11. Furthermore, the cantilever 11 can be displaced by electrostatic force or a piezoelectric actuator, but FIG. 2 shows a case where electrostatic force is used, and by applying a voltage to the electrostatic actuator electrode, the electrostatic force can be The cantilever 11 can be driven by.

FIG. 3 is a view of a part of the opposing multi-probe and recording medium in FIG. 1, viewed diagonally from below.

FIG. 4 shows the configuration of a second information processing apparatus of the present invention.

In FIG. 4, 201 is an XY stage;
03 is a multi-probe support stand, 204 is a Z-axis coarse movement linear actuator that drives the multi-probe in the Z-axis direction, and 205 and 206 are the XY stages 201, respectively.
A linear actuator for driving in the Y direction, 310 a bias circuit for recording and reproduction, 301 a detection circuit for a tunnel current flowing between the probe 10 and the recording layer 4, and 302 a Z actuator for moving the cantilever in the Z-axis direction. A servo circuit for fine axis movement; 303 is a Z-axis coarse movement servo circuit for driving the linear actuator; 304 is a drive circuit for moving the cantilever in the Z-axis direction; 311 is an XY scanning drive circuit for controlling the position of the XY stage; 309 is a computer that controls these scans.

Next, FIGS. 6 and 7 show a perspective view and a sectional view of a third recording medium cassette of the present invention. This recording medium cassette 601 has a recording medium 7 enclosed in a container having an openable/closable hood 602 in a state where it is almost shielded from the outside air, and a contact electrode 603 connected to an electrode of the recording medium 7 is placed outside the recording medium cassette. It is set up.

By forming the recording medium into a cassette in this manner, it is not exposed to the outside air even when it is not installed in an information processing apparatus, and it is possible to prevent damage to the recording medium 7 and the adhesion of dust and the like.

FIG. 8 shows a state in which the recording medium cassette shown in FIG. 6 is installed in a recording/reproducing apparatus, that is, a sectional view of the fourth information processing apparatus of the present invention. FIG. 8 shows a sectional view of the insertion portion of the recording medium cassette. In the figure, 804 is an XY drive mechanism of the multi-probe 2, and 805 is a Z-axis drive mechanism. The fourth information processing apparatus of the present invention is capable of mounting the recording medium cassette 601 of the third invention, and has a mechanism for opening the hood 602 when the recording medium cassette 601 is mounted.
The recording medium 7 in the recording medium cassette 601 is in a state where it can meet with the multi-probe 2 in the information processing device 803, and the information processing device 803 and the recording medium 7 are electrically connected by the contact electrode 603. The book shown in Fig. 4 is basically the same as the one shown in Fig. 4, except that a voltage is applied to the probe and the electrode of the recording medium 7, the current flowing through the probe is detected, and information processing such as recording, reproduction, or erasing can be performed. This is the same as the second information processing device of the invention.

[0025]

EXAMPLES Example 1 Recording, reproducing and erasing experiments were conducted using the information processing apparatus shown in FIG.

First, four layers of polyimide made of 4,4'-diaminodiphenyl ether and pyromellitic anhydride were formed by the LB method on a recording substrate made of doped silicon on which projections were formed, and this was used as a recording layer. At this time, the thickness of the polyimide recording layer was about 1.6 nm. This recording medium was attached to a recording/reproducing device to form an information processing device.

[0027] The multi-probe used had a probe head in a part of the center as shown in FIG. The flat portion other than the probe head acts as a sliding surface that comes into contact with a protrusion provided on the recording medium when the multi-probe moves while maintaining a constant interval between recording surfaces.

The probe head or probe was mounted at a distance of several mm or more so as not to come into contact with the recording layer. From this state, the recording medium was brought closer using the Z-axis coarse movement mechanism. When approaching, no voltage is applied between the probe and the electrode.
That is, the approach was made without detecting the tunnel current and applying feedback based on the detected result. The relative approach of the multi-probe and the recording medium is continued until the multi-probe contacts a protrusion provided on a part of the recording medium, and upon contact, the movement of the Z-axis coarse movement mechanism is stopped and the position is maintained. At this time, since the spacing in the Z direction is controlled by physical protrusions, no control operation is required to maintain a constant spacing on the order of microns.

Next, +1.
A voltage of 5 V was applied, and the distance (Z) between the probe and the recording layer surface was adjusted while monitoring the current. At this time, the current Ip for controlling the distance Z between the probe and the surface of the recording layer is set to 10-
Information was recorded under settings such that 10A≧Ip≧10-11A. Such information is recorded by setting the probe to the + side and the substrate electrode to the - side, and determining the threshold voltage VthON at which the four layers of the polyimide LB film change to a low resistance state (ON state).
The above rectangular pulse voltage (FIG. 5) was applied. The results showed that a probe current of about 10 nA flowed in the recording bit, indicating that it was in an ON state.

[0030] Note that the probe voltage is turned on when the electric memory material is turned on.
Threshold voltage VthOF that changes from state to OFF state
As a result of setting the voltage to 10V, which is higher than F, and tracing the recorded position again, it was confirmed that all the recorded states were erased and the state transitioned to the OFF state.

Further, in this embodiment, the recording layer was formed by the LB method, but any method capable of forming an inorganic or organic recording material, such as a vapor deposition method or an adsorption method, may be used.

Next, the recording medium and the multi-probe were relatively moved two-dimensionally by driving an XY stage using a linear actuator. At this time, the cantilever was moved upward to a region where currents such as tunnel currents could not be detected. Since the probe head exists only in a part of the multi-probe surface, it is possible to place the probe head anywhere on the recording surface without the probe head or probe touching the recording medium. I confirmed that.

Example 2 2,2-bis(
4,4'diaminodiphenyl)-1,1,1,3,3,
Four layers of polyimide made of 3-hexafluoropropane and pyromellitic anhydride were formed by the LB method, and the same experiment was conducted using this as the recording layer, and the same results as in Example 1 were obtained.

Example 3 Recording, reproducing and erasing experiments were conducted using the recording medium cassette shown in FIG.

First, 4, 4
Four layers of polyimide consisting of '-diaminodiphenyl ether and pyromellitic anhydride were formed by the LB method, and this was used for the recording layer. At this time, the thickness of the polyimide recording layer was about 1.6 nm. This recording medium was placed in a container as shown in FIG. 7 to form a recording medium cassette.

[0036] This cassette was installed in a recording/reproducing device. This recording/reproducing device is provided with a hook, and when a recording medium cassette is attached, the hood can be opened by hooking the hook provided on the hood. Further, when the recording medium cassette is removed, the hood is closed by a restoring mechanism such as a spring provided inside the cassette. In this example, the same experiment as in Example 1 was conducted, and similar results were obtained.

[0037]

[Effects of the Invention] According to the present invention, the following effects can be obtained. ■It has become easier to load the recording medium into the recording/reproducing device. (2) Due to the protrusions provided on the recording medium, it is easy to maintain a constant interval on the order of microns when the multi-probe is moved widely on the recording surface. - Since the area exposed to the outside air during recording and reproduction is reduced, deterioration of the recording medium due to dust and the like is reduced. (2) When an organic thin film is formed on the sliding surface of a recording medium, it is possible to improve the durability of the sliding surface and improve the sliding properties.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a recording medium of the present invention in contact with a multi-probe.

FIG. 2 is an enlarged sectional view of the multi-probe in FIG. 1.

FIG. 3 is a diagram illustrating a portion of the facing multi-probe and recording medium in FIG. 1 as viewed diagonally from below.

FIG. 4 is a diagram showing the configuration of an information processing device of the present invention.

FIG. 5 is a diagram showing a rectangular pulse voltage waveform applied in an example.

FIG. 6 is a perspective view of a recording medium cassette of the present invention.

FIG. 7 is a sectional view of the recording medium cassette of the present invention.

FIG. 8 is a diagram showing the configuration of an information processing device of the present invention.

[Explanation of symbols]

1 Probe head 2. Multi-probe 3 Board 4 Recording layer 5 Electrode 6.Protrusion 7 Recording medium 8 Sliding surface 10 Probe 11 Cantilever 13　Electrode for electrostatic actuator 201 XY stage 203 Multi-probe support stand 204 Linear actuator 205 Linear actuator 206 Linear actuator 301 Tunnel current detection circuit 302 Z-axis fine movement servo circuit 303 Z-axis coarse movement servo circuit 304 Z drive circuit 309 Computer 310 Bias circuit 311 XY scan drive circuit 601 Recording medium cassette 602 Hood 603 Contact electrode 803 Recording/playback device 804 XY drive mechanism 805 Z drive mechanism

Claims (7)

[Claims] 1. A recording medium characterized by having a protrusion that surrounds a recording surface and forms a closed space. 2. Claim 1, wherein an organic thin film is formed on the sliding surface of the protrusion that contacts the probe support substrate.
Recording medium described. 3. The recording medium according to claim 2, wherein the organic thin film is made of polyimide. 4. The recording medium according to claim 3, wherein the polyimide contains a fluorine atom. 5. A recording medium having a protrusion surrounding a recording surface to form a closed space, a multi-probe having a plurality of probes, means for applying a recording and/or erasing voltage to the recording medium, and a recording medium. and means for detecting and reproducing a tunnel current or field emission current flowing between the probe and the probe. 6. A recording medium having a protrusion surrounding a recording surface and forming a closed space is placed in a container having a hood that can be opened and closed, and a contact electrode connected to an electrode of the recording medium is provided outside the container. A recording medium cassette characterized by: 7. A recording medium having a protrusion surrounding a recording surface and forming a closed space is placed in a container having a hood that can be opened and closed, and a contact electrode connected to an electrode of the recording medium is provided outside the container. A recording medium cassette, a multi-probe having a plurality of probes, a mechanism for opening and closing the hood when the recording medium cassette is attached, a means for applying recording and/or erasing voltage to the recording medium, and a recording medium and An information processing device comprising: means for detecting and reproducing a tunnel current or field emission current flowing between probes.