JPH08235653A - Scanning probe recording / reproducing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an apparatus capable of recording and reproducing information in an extremely small area in the atmosphere. [Structure] Information is written by causing a dielectric breakdown in a very small area by applying a voltage on the surface of a recording medium, and scanning the surface of the recording medium to detect a region where an electric resistance value is changed by the dielectric breakdown and then information is recorded. A probe electrode for reading the data, a current measuring device for measuring a tunnel current value accompanying the scanning of the probe electrode, a piezo element for driving the probe electrode while keeping a constant distance from the recording medium, and a piezo element. The scanning probe recording / reproducing apparatus comprises a piezo element control device for controlling the element. The recording medium has a film thickness of 1 to 20 n on the surface of the conductor substrate.
The insulating thin film of m is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning probe recording / reproducing apparatus which is composed of a probe and a recording medium and enables recording / reproducing in an extremely small area.

[0002]

2. Description of the Related Art In recent years, a scanning tunnel microscope (scanning tunnel) having atomic-scale resolution has been developed.
ing Microscope (hereinafter abbreviated as STM) was invented to enable real-space observation of atoms and molecules. ST
The principle of M is to apply various voltages between the probe and the conductive sample that are brought close to each other by a distance of about 1 nm, and detect the tunnel current flowing between the two to detect various shapes and electron distribution states of the sample surface. This is to get information. Further, although the measurement is limited to the conductive material, it is also applied to the structural analysis of the insulating film thinly formed on the surface of the conductive material. From the above, if the principle of STM is applied, it becomes possible to perform high-density recording / reproduction on the atomic order. For example, glassy Rh ₂₅ Zr ₇₅ and Co ₃₅ T in ultra high vacuum.
When the sample surface b ₆₅ is recrystallized by dissolving in a current of STM, the method (U.Staufer et utilizing that pulled probe side and fixed as conical projections
al. Z. Phys. B, 77, 281, 1989),
A method of applying a negative voltage to an Au probe in an ultra-high vacuum and depositing Au in clusters on an Au substrate by field emission to perform writing (HJ Mamin et al.
al. : J. Vac. Sci. Technol. ，
B, 9, 1398, 1991), a diamond obtained by vapor phase synthesis is used to remove atoms one by one by passing an electric current between the probe and the diamond, and recording / reproducing depending on the presence or absence of atoms on the diamond surface. Method (JP-A-5-101456): Recording is performed by accumulating charges in a dielectric layer by a needle-shaped electrode using a recording medium having a double dielectric layer / semiconductor or a conductor structure, and recording the charge. Japanese Patent Laid-Open No. 5-81711 and the like are disclosed.

[0003]

However, since all of the above methods use a clean surface, an ultrahigh vacuum, a low temperature environment for maintaining the stability of the surface, or a low electric field environment for maintaining the dielectric state, etc. Is required, and a special environment is indispensable for recording / reproducing in a target very small area. Further, there is a problem that a large-scale vacuum device, a cooling device, an external electric field shielding device, etc. are required to realize these environments.

In view of these problems, an object of the present invention is to provide an apparatus capable of recording / reproducing information in a very small area in the atmosphere.

[0005]

In order to solve the above-mentioned problems, a scanning probe recording / reproducing apparatus of the present invention writes information by causing a dielectric breakdown in a very small area by applying a voltage on the surface of a recording medium. Along with, a probe electrode that scans the surface of the recording medium to detect a region where the electrical resistance value has changed due to dielectric breakdown and reads information, and a current measuring device that measures a tunnel current value associated with the scanning of the probe electrode, It is characterized by comprising a piezo element for driving the probe electrode while keeping a constant distance from the surface of the medium, and a piezo element control device for controlling the piezo element. Further, the recording medium is a recording medium in which an insulating thin film having a film thickness of 1 to 20 nm is formed on a surface of a conductor substrate.

[0006]

The insulating thin film has a characteristic that it locally causes dielectric breakdown by applying a high electric field using a probe. By utilizing this characteristic, in the scanning probe recording / reproducing apparatus according to the present application, information can be written in a very small area of the insulating thin film. In addition, the area where the insulation breakdown occurred
Since the electric resistance value is smaller by several orders of magnitude than that of other portions, in the scanning probe recording / reproducing apparatus according to the present application, by scanning the probe electrode and detecting the low resistance region,
Information can be read.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A scanning probe recording / reproducing apparatus of the present invention comprises a recording medium 1, a platinum probe electrode 2, a DC power source 3, a current measuring device 4, a piezo element 5, and a piezo element control device 6, as shown in FIG. To be done. The piezo element drives the platinum probe electrode 2, and the recording medium 1 used is a single-crystal silicon surface on which a 20-nm-thick silicon oxide thin film is formed by a sputtering method.

In FIG. 2A, a DC power source 3 applies 2 V between the recording medium 1 and the platinum probe electrode 2 so that the platinum probe electrode 2 side becomes a positive electrode, and the piezoelectric element 5 is controlled to control the platinum probe. When the platinum probe electrode 2 was moved 10 nm in one direction on the surface of the recording medium 1 while keeping the distance between the tip of the electrode 2 and the surface of the silicon oxide thin film recording medium 1 nm, platinum measured by the current measuring device 4 was measured. It shows a tunnel current value flowing between the probe electrode 2 and the recording medium 1.

In recording information, first, the distance between the tip of the platinum probe electrode 2 and the surface of the silicon oxide thin film recording medium 1 is set to 1 n.
While maintaining m, the platinum probe electrode 2 was moved by 5 nm in one direction over the surface of the recording medium 1 without applying a voltage.
Next, the platinum probe electrode 2 is stopped at that position, and 10 V is pulsed from the DC power source 3 between the recording medium 1 and the platinum probe electrode 2 so that the platinum probe electrode side becomes the positive electrode.
It was applied for m seconds to cause dielectric breakdown. Then, a process of moving 5 nm again without applying a voltage was performed.

In FIG. 2 (b), the portion of the silicon oxide thin film recording medium 1 on which the dielectric breakdown treatment has been performed is set to 2 V so that the platinum probe electrode 2 side becomes the positive electrode by the DC power source 3 in the same manner as described above.
When the platinum probe electrode 2 is moved by 10 nm in one direction on the surface of the recording medium 1 while maintaining the distance between the tip of the platinum electrode 2 and the surface of the silicon oxide thin film recording medium 1 at 1 nm by controlling the piezoelectric element 5, 2 shows the tunnel current value flowing between the platinum probe electrode 2 and the recording medium 1 measured by the current measuring device 4.

Comparing FIG. 2A and FIG. 2B, 1
At a location where a dielectric breakdown was caused by applying a pulsed DC electric field of 0 V, a tunnel current having a width of 2 nm was flowing due to the application of voltage. This shows that information can be recorded and reproduced by using the dielectric breakdown of the insulating thin film.

[0012]

In the scanning probe recording / reproducing apparatus of the present invention, by using the dielectric breakdown of the insulating thin film, the recording / reproducing of information in an extremely small area can be stably performed in the atmosphere by using the DC power supply. .

[Brief description of drawings]

FIG. 1 is a diagram showing a scanning probe recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram showing a relationship between an insulating film surface position and a tunnel current value.

[Explanation of symbols]

 1 recording medium 2 platinum probe electrode 3 direct current 4 current measuring device 5 piezo element 6 piezo element control device

Claims (2)

[Claims] 1. A voltage is applied to the surface of a recording medium to cause dielectric breakdown in an extremely small area to write information, and the surface of the recording medium is scanned to detect a region where the electrical resistance value has changed due to the dielectric breakdown. A probe electrode for reading information, a current measuring device for measuring a tunnel current value associated with the scanning of the probe electrode, and a piezo element for driving the probe electrode while keeping a constant interval with respect to the surface of the recording medium. And a piezo element control device for controlling the piezo element. 2. The scanning probe recording / reproducing apparatus according to claim 1, wherein the recording medium is a recording medium in which an insulating thin film having a film thickness of 1 to 20 nm is formed on a surface of a conductor substrate.