KR19990070783A - High Density Data Storage Using Ferroelectric - Google Patents

Abstract

The present invention provides a high-density data storage including a data storage medium in which lower electrodes and ferroelectrics are stacked on a substrate, a tip for forming a local electric field in the data storage medium, and a tip holder for fixing the tip. In particular, the device is characterized in that a diamond-like carbon (DLC) thin film is laminated on a ferroelectric material of a data storage medium. Accordingly, there is an advantage that the friction and wear characteristics are improved even in the near contact or the full contact mode.

Description

High Density Data Storage Using Ferroelectric

The present invention relates to a high density data storage system using a ferroelectric.

Generally, AFM (Atomic Force Microscope) or STM (Scanning Tunneling Microscope) is used to analyze the surface state of an object. In this case, the tip is analyzed while scanning the surface of the object, and the electrical bias between the tip and the object is applied, and the STM mode is classified, and if there is no bias, the AFM mode is classified.

As described above, the method of driving the high density data storage device using the STM mode is illustrated in FIG. 1. By applying a voltage between the tip holder 2 formed at one end of the conductive material 1 and the ferroelectric 4 which is a data storage medium, the electric field 3 is formed between the conductive tip 1 and the ferroelectric 4 Data is recorded on the thin film of the ferroelectric 4. At this time, since the bit size is determined by the electric field distribution between the tip 1 and the ferroelectric 4, the recording density depends on the distance between the tip 1 and the ferroelectric 4. Therefore, in order to improve the recording density, a near contact mode that closes the distance between the tip 1 and the ferroelectric 4 or a full contact mode that brings the tip 1 and the ferroelectric 4 into contact with each other. High density data storage must be operated in contact mode.

However, in such a high density data storage device, the ferroelectric rotates at high speed. Therefore, in the high-density data storage device operating in the near contact mode or the full contact mode, vibration due to the rotation of the ferroelectric tends to occur, which causes friction and wear between the tip and the ferroelectric, thereby shortening the lifespan. .

An object of the present invention is to provide a high-density data storage device using a ferroelectric having improved friction and wear characteristics in a near contact mode or a full contact mode.

1 is a view showing a conventional high density data storage device.

2 illustrates a near contact mode of a high density data storage device in accordance with the present invention.

3 illustrates a full contact mode of a high density data storage device in accordance with the present invention.

Explanation of symbols for the main parts of the drawings

10 ... tip holder

20 ... tip deposited conductive diamond-like carbon (DLC) thin film

30 ... Data Storage Media 310 ... Substrate

320 ... bottom electrode 330 ... ferroelectric

340 Diamond-like Carbon (DLC) Thin Films

In order to achieve the above object, the high-density data storage device using a ferroelectric according to the present invention, the data storage medium in which the lower electrode, the ferroelectric is deposited on the substrate; A tip for forming an electric field local to the data storage media; And a tip holder for fixing the tip, wherein the thin film has a diamond-like carbon (DLC) thin film laminated on the ferroelectric of the data storage medium.

In the present invention, the tip is preferably a conductive diamond-like carbon (DLC) thin film, conductive ceramic and conductive diamond thin film is deposited. In this case, the conductive diamond-like carbon thin film or the conductive diamond thin film deposited on the tip is preferably doped with p-type or n-type.

In addition, the thickness of the diamond-like carbon thin film deposited on the ferroelectric is preferably 0.001 μm to 1 μm.

The gap between the tip and the diamond-like carbon thin film is preferably 200 nm or less.

Hereinafter, a high density data storage device using a ferroelectric according to the present invention with reference to the drawings.

In the present invention, in order to realize a high-density data storage device using a steel dielectric, a tip on which a conductive diamond-like carbon (DLC) thin film is deposited is used, and a ferroelectric is used as a data storage medium. A diamond-like carbon (DLC) thin film is also deposited on the ferroelectric.

In the present specification, diamond-like carbon (DLC) includes high hardness amorphous carbon such as hydrogenated amorphous carbon, tetrahedrally bonded amorphous carbon, and the like.

According to the present invention, there is a near contact state that closely closes the gap between the tip and the diamond-like carbon (DLC) thin film or a full contact contacting the tip and the diamond-like carbon (DLC) thin film. ), The data storage media can be rotated at high speed, so that data can be stored at a high density. This will be described in detail with reference to Examples.

2 and 3 are diagrams illustrating a high-density data storage device using a ferroelectric according to the present invention, and FIG. 2 is a diagram illustrating a case where the tip and the data storage media are operated in the near contact mode, and FIG. 3 is a tip and data. A diagram showing a case where the storage media is operated in the full contact mode.

As shown in FIGS. 2 and 3, the high density data storage device according to the present invention includes a tip 20 and a data storage medium 30 supported by the tip holder 10. Tip 20 is deposited with a conductive diamond-like carbon (DLC) thin film, conductive ceramic and conductive diamond thin film. In this case, the deposited conductive diamond-like carbon (DLC) thin film or conductive diamond thin film is doped to p-type (or n-type). The data storage media 30 has a structure in which a substrate 310, a lower electrode 320, a ferroelectric 330, and a diamond-like carbon (DLC) thin film 340 are sequentially stacked. The diamond-like carbon (DLC) thin film 340 has a thickness of 0.001 μm to 1 μm. On the other hand, the distance between the tip 20 and the diamond-like carbon (DLC) thin film 340 is to be 200nm or less.

A high density data storage device using a ferroelectric having such a configuration operates as follows.

First, an electric field is applied between the tip 20 serving as the upper electrode and the lower electrode 320 of the data storage medium 30. Due to this electric field, polarization occurs in the ferroelectric material 330. Polarization in the ferroelectric material 330 occurs locally depending on the position of the tip 20, and the size of the polarized region (typically a bit reference) is the tip 20 and data storage. It is determined by the electric field distribution between the media 30. Therefore, as the distance between the tip 20 and the data storage medium 30 decreases, the distribution of the equi-potential electric field line becomes dense and the polarized area becomes smaller, thereby increasing the density of data storage. Is achieved.

That is, as shown in FIG. 2, when the tip 20 and the data storage medium 30 are in the near contact mode spaced apart at intervals of 200 nm or less, the tip 20 and the data storage are reduced as the distance decreases. The distribution of the isoelectric lines between the media 30 becomes dense, thereby reducing the size of the polarization region formed in the ferroelectric 330. Further, even if the data storage media 30 rotates at high speed, the conductive diamond-like carbon (DLC) thin film deposited on the tip 20 and the diamond-like carbon (DLC) 340 deposited on the ferroelectric 330 may be used. Due to this, the friction and wear characteristics are improved.

Meanwhile, as shown in FIG. 3, in the full contact mode where the tip 20 and the data storage medium 30 are in contact with each other, the distribution of the isoelectric line between the tip 20 and the data storage medium 30 is The density is maximized, and the size of the polarization region formed in the ferroelectric 330 is minimized. In addition, the friction and wear characteristics degraded by the full contact between the tip 20 and the data storage media 30 that rotates at high speed may include the conductive diamond-like carbon thin film deposited on the tip 20 and the ferroelectric 330. It is improved due to the diamond-like carbon thin film 340 deposited thereon.

As described above, according to the high-density data storage device using the ferroelectric according to the present invention, the conductive diamond-like carbon thin film is deposited on the tip 2 and the diamond-like carbon thin film 34 is deposited on the ferroelectric 33. In this way, the friction and wear characteristics are improved even in the near contact or full contact mode, thereby extending the life of the device.

Claims (5)

A data storage medium in which lower electrodes and ferroelectrics are sequentially stacked on the substrate; A tip for forming an electric field local to the data storage media; And A high density data storage device having a tip holder for fixing the tip, comprising: High density data storage device, characterized in that the diamond-like carbon (DLC) thin film is laminated on the ferroelectric of the data storage media. The method of claim 1, And a conductive diamond-like carbon (DLC) thin film, a conductive ceramic and a conductive diamond thin film deposited on the tip. The method of claim 2, The conductive diamond-like carbon thin film or the conductive diamond thin film deposited on the tip is doped with p-type or n-type. The method of claim 1, The diamond-like carbon thin film deposited on the ferroelectric has a thickness of 0.001 μm to 1 μm. The method of claim 1, And a gap between the tip and the diamond-like carbon thin film is 200 nm or less.