KR19990069112A - Near field emitters and high density recording devices using the same - Google Patents

Abstract

The present invention provides a near field emitter and a high density recording device using the same for medium to next-generation high data storage, such as a compact disk (CD), a digital multipurpose disk (DVD), a hard disk drive (HDD), and the like. How it works. The near field emitter according to the present invention records or decodes data on a ferroelectric recording medium by using an electron beam emitted by a flat ferroelectric emitter or a general metal or semiconductor emitter. Since the electron beam is emitted remotely from the recording medium and the emitter, no error due to vibration occurs.

Description

Near-field emitters and high-density recording devices using them and methods of operation

The present invention provides a near field emitter suitable for medium to next generation high data storage, including compact disc (CD), digital versatile (versatile) disc (DVD), and hard disk drive (HDD). A high density recording apparatus and a method of operating the same.

High data storage research is most popular in data storage by AFM, or STM. However, these are critical vibration-sensitive vulnerabilities and require the ability to read and write data remotely. The most suitable for this is an electron beam. That is, the best match for the next generation high data storage media following CD, DVD, HDD, etc. is to use electron as a recording source. Electron beams are used in SEM, TEM, electron-beam lithography, and the like, but have focused on forming focused beams. However, they are not suitable for data storage because they are large and expensive to apply electron beam sources to high data storage systems.

Alternatively, a field emitter is emerging as a device that can simply generate an electron beam. However, in field emission, a physical limitation that an electron beam spreads in all directions is a problem.

The present invention was devised to improve the above problems, and a near field emitter (Near Field Emitter) which can be used as an electron beam source to apply an electron beam to high data storage, and the same An object of the present invention is to provide a high-density recording apparatus and a method of operating the same.

1 is a schematic vertical cross-sectional view of a ferroelectric near field emitter in accordance with the present invention;

Figure 2 is a schematic vertical cross-sectional view of a general material near field emitter according to the present invention,

3 is a schematic perspective view of the near field emitter of FIGS. 1 and 2;

4 is a schematic vertical cross-sectional view of the ferroelectric near field emitter of FIG. 1 with a grid, FIG.

5A to 5D are diagrams for explaining an operation method when the near field emitter has a collector in the high density recording apparatus according to the present invention;

5A is a diagram for explaining a step of initializing a ferroelectric recording medium;

5b shows "write",

5C shows the principle of reading what is written as "0";

And FIG. 5D shows the principle of reading what is written as "1".

<Description of the symbols for the main parts of the drawings>

1.Emitter holder and emitter bottom electrode or cathode

Ferrolectrc emitter

3. Top electrode

4. Collector

5. Common emitters (metals, diamonds, pseudo diamonds, etc.)

6. Insulating gate

7. Light or photons (when using diamond or pseudo diamond emitters)

8. Separators (insulators) of ferroelectric emitters and grids

9. Grid

10. Recording medium (ferroelectric)

11. Upper electrode

12. Bottom electrode

13. The dielectric film

Near field emitter according to the present invention to achieve the above object, the emitter holder; An emitter formed by mounting a ferroelectric in a flat plate shape on the emitter holder; And a conductive gate having an electron beam emission hole of a constant diameter on the emitter.

In the present invention, it is preferable to further include a collector disposed on the emitter holder spaced apart from the emitter by a predetermined distance, further comprising an acceleration grid for accelerating the electron beam emitted on the conductive gate. desirable.

In addition, another near field emitter according to the present invention in order to achieve the above object, the emitter holder; An emitter formed by flatly mounting metal, diamond or pseudo diamond on the emitter holder; And an insulating gate having an electron beam emission hole having a constant diameter on the emitter.

In the present invention, it is preferable to further include a collector disposed on the emitter holder spaced apart from the emitter by a predetermined distance, further comprising an acceleration grid for accelerating the electron beam emitted on the conductive gate. desirable.

In addition, in order to achieve the above object, a high density recording apparatus using a near field emitter according to the present invention includes an emitter holder, an emitter formed by mounting a ferroelectric on the emitter holder in a flat plate shape, and the emitter image. A near field emitter having a conductive gate having a hole for emitting electron beams of a predetermined aperture in the chamber; And a recording medium having upper and lower electrodes formed on upper and lower surfaces of the ferroelectric layer and the ferroelectric layer, respectively.

In the present invention, it is preferable to further include a collector disposed on the emitter holder spaced apart from the emitter by a predetermined distance, further comprising an acceleration grid for accelerating the electron beam emitted on the conductive gate. Preferably, the upper and lower electrodes of the recording medium are formed of a metal, a conductive ceramic or a semiconductor, and a dielectric film is formed on the upper electrode, but the dielectric film is formed of an insulator, a dielectric, or a high dielectric material.

In addition, in order to achieve the above object, another high-density recording apparatus using the near field emitter according to the present invention is formed by mounting a metal, diamond or pseudo diamond on the emitter holder and the emitter holder in a flat plate shape. A near field emitter having an emitter and an insulating gate having an electron beam emission hole of a constant diameter on the emitter; And a recording medium having upper and lower electrodes formed on the upper and lower surfaces of the ferroelectric layer and the ferroelectric layer, respectively, and a dielectric film formed on the upper electrode, respectively.

In the present invention, it is preferable to further include a collector disposed on the emitter holder spaced apart from the emitter by a predetermined distance, further comprising an acceleration grid for accelerating the electron beam emitted on the conductive gate. Preferably, the electrode of the recording medium is formed of a metal, a conductive ceramic or a semiconductor, and a dielectric film is formed on the upper electrode, but the dielectric film is formed of an insulator, a dielectric or a high dielectric material.

In addition, in order to achieve the above object, a method of operating the high density recording apparatus according to the present invention, in the high density recording apparatus having a near field emitter and a ferroelectric recording medium, (A) the near field emitter A writing step of recording information by emitting an electron beam on the ferroelectric recording medium to change the polarization state of the ferroelectric recording medium; And (b) reading the information by emitting an electron beam to the ferroelectric recording medium with the near field emitter to detect a difference in potential or electric field formed on the dielectric film according to the polarization state of the ferroelectric layer of the ferroelectric recording medium; Characterized in that it comprises a.

In the present invention, the method further comprises the step of initializing the ferroelectric recording medium prior to the step (a), and preferably reading the information by detecting that the electron beam emitted in the step (b) is scattered.

Hereinafter, a near field emitter, a high density recording apparatus using the same, and a method of operating the same according to the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are schematic vertical cross-sectional views of a near field emitter according to the present invention, respectively, with ferroelectric type near field emitters using ferroelectrics as emitters and metal, diamond, or similar diamonds or semiconductors as emitters General near field emitter. As shown, the near field emitter according to the present invention is an application of a flat type field emitter. That is, the near field of the electron beam generated in the flat field emitter is used. In general, in the near field, the beam intensity is irregular, and there is little beam spread. According to optical theory, the near field is determined by the size of the emitter and the wavelength (or electron beam energy) of the electron. By fabricating an emitter having such near field beams, small electron beam spots can be obtained remotely, and data can be recorded and reproduced using them. 1 and 2 show the structure of the emitter satisfying these conditions. First, in a ferroelectric near field emitter using the ferroelectric 2 as an emitter, a general near field emitter using a conductive material as the upper electrode 3, that is, the gate 3, and using a general emitter 5 Insulator gate 6 is used. Here, the member number 1 is a cathode for supplying electrons, and the member number 4 is a collector for collecting electrons. As shown in FIG. 3, a minute hole is drilled in the center of the gates 3 and 6 and the emitters 2 and 5 are exposed so that electrons provided from the cathode 1 are emitted through the holes. To control the energy of emitted electrons or to block the spread of the beam first, as shown in FIG. 4, a grid 9 having a small hole is mounted. Can also be used. Here, the grid 9 is interposed between the insulator 8 so as to be electrically insulated from the gate 3.

The high-density recording according to the present invention is to emit an electron by applying a voltage to the emitter 2 having such a structure and to place a recording object or a recording medium in a near field area of an emission pattern. Device. 5A to 5D show such a high density recording apparatus and its operation method according to the present invention. Here, an example is used in which a ferroelectric substrate is used as the recording medium. The ferroelectric substrate 10 includes an upper electrode 11 and a lower electrode 12, which can be viewed as a ferroelectric capacitor. Electrode materials include metals, conductive ceramics and semiconductors. First, the ferroelectric substrate, which is a recording medium, is initialized by polarizing as a whole as shown in FIG. 5A. Thereafter, as a near field emitter, as shown in FIG. 5B, the bottom electrode 12 of the substrate is grounded, and then electrons are irradiated to a specific portion of the ferroelectric substrate so that the substrate is locally polarized reversed. When the ferroelectric substrate is polarized, a domain opposite to that of the initialization is formed, and an electric field is formed by the domain. At this time, when electrons are emitted to the substrate again, the scattering of the electrons on the substrate surface varies depending on the domain direction. For example, electron scattering may be strongly generated by a negative electric field in a region where an upper domain is formed, and scattering may be less or even absorbed by a bidirectional electric field in a region where a lower domain is formed. Using this point, information is read as shown in Figs. 5C and 5D.

As described above, the near field emitter according to the present invention uses electron beam emission to record or decode data. Since the electron beam emission process proceeds remotely from the recording medium and the emitter, the malfunction in recording and reproduction due to vibration is reduced. In particular, if the holder is fixed and the substrate is moved to store and reproduce the information, the safety against vibration is improved. In addition, the high-density recording device using the same concept is the same as the operation method of the conventional CD, DVD, and is more practical than the data storage by AFM or STM.

Claims (22)

Emitter holder; An emitter formed by mounting a ferroelectric in a flat plate shape on the emitter holder; And A conductive gate having holes for emitting electron beams of a constant diameter on the emitter; Near field emitter, characterized in that provided. The method of claim 1, And a collector disposed on the emitter holder and spaced apart from the emitter by a predetermined distance. The method according to claim 1 or 2, And an acceleration grid for accelerating the electron beam emitted on the conductive gate. Emitter holder; An emitter formed by mounting a metal in a flat plate shape on the emitter holder; And An insulating gate having holes for emitting electron beams of a constant diameter on the emitter; Near field emitter, characterized in that provided. The method of claim 4, wherein The emitter is a near field emitter, characterized in that the diamond or pseudo-diamond is formed in a flat plate instead of the metal. The method of claim 4, wherein And a collector disposed on the emitter holder and spaced apart from the emitter by a predetermined distance. The method according to any one of claims 4 to 6, And an accelerating grid for accelerating electron beams emitted on said insulating gates. A near field emitter having an emitter holder, an emitter formed by mounting a ferroelectric on the emitter holder in a flat plate shape, and a conductive gate having an electron beam emission hole having a predetermined diameter on the emitter; And A recording medium having upper and lower electrodes formed on upper and lower surfaces of the ferroelectric layer and the ferroelectric layer, respectively, and a dielectric film formed on the upper electrode. A high density recording device, characterized in that provided. The method of claim 8, And a collector disposed on the emitter holder spaced apart from the emitter by a predetermined distance. The method according to claim 8 or 9, And an acceleration grid for accelerating the electron beam emitted on the conductive gate. The method of claim 8, And the electrode of the recording medium is formed of at least one of a metal, a conductive ceramic and a semiconductor. The method of claim 8, And the dielectric film of the recording medium is formed of at least one of an insulator, a low dielectric material, and a high dielectric material. A near field emitter having an emitter holder, an emitter formed by flatly mounting metal on the emitter holder, and an insulated gate having an electron beam emission hole of a constant diameter on the emitter; And A recording medium having upper and lower electrodes formed on upper and lower surfaces of the ferroelectric layer and the ferroelectric layer, respectively, and a dielectric film formed on the upper electrode. A high density recording device, characterized in that provided. The method of claim 13, The emitter is a near field emitter, characterized in that the diamond or pseudo-diamond is formed in a flat plate instead of the metal. The method of claim 13, And a collector disposed on the emitter holder spaced apart from the emitter by a predetermined distance. The method according to any one of claims 13 to 15, And an acceleration grid for accelerating the electron beam emitted on the conductive gate. The method of claim 13, An electrode of the recording medium is formed of a metal or a conductive ceramic. The method of claim 13, And the dielectric film of the recording medium is formed of at least one of an insulator, a low dielectric material, and a high dielectric material. A high density recording apparatus comprising a near field emitter and a ferroelectric recording medium, (A) writing to record information by emitting an electron beam on the ferroelectric recording medium with the near field emitter to change the polarization state of the ferroelectric recording medium; And (B) reading the information by emitting an electron beam to the ferroelectric recording medium with the near field emitter to detect a difference in potential formed on the dielectric film on the upper electrode according to the polarization state of the ferroelectric layer of the ferroelectric recording medium; To A method of operating a high density recording device, characterized in that it comprises a. The method of claim 19, And initiating said ferroelectric recording medium prior to said step (a). The method of claim 19, And (b) reading the information by detecting the difference of the electric field formed on the dielectric film on the upper electrode in the step (b). The method of claim 19, And (b) read the information by detecting the scattering of the electron beam emitted in step (b).