JPS63124237A - Optical memory element - Google Patents

Abstract

PURPOSE:To obtain an optical memory element capable of reproducing signals with high sensitivity without using a laser light source by providing a Schottky varrier type semiconductor element based on junction between a semiconductor and metal with a high resistance layer formed between the semiconductor and the metal. CONSTITUTION:The high resistance layer 2 and a metal electrode layer 3 are successively formed on the surface of a semiconductor substrate 1. When a voltage is impressed to the substrate 1 and the layer 3, voltage destruction of the layer 2 is generated and Schottky junction based on the base 1 and the layer 3 is obtained at the portion. Although said voltage destruction part generates optical electromotive force and rectifying action, the substrate 1 is insulated from the layer 3 through the layer 2 on a portion having no voltage impression and optical electromotive force and rectifying action based on Schottky junction are not generated on the portion. Thus, the memory element for detecting the existence of optical electromotive force by impressing a voltage at the time of recording and radiating light 4 near the layer 3 at the time of reproducing can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an optical memory device, and particularly to an optical memory device with excellent reproduction sensitivity.

[Conventional technology]

In recent years, with the rapid increase in the amount of information, memory devices using light have been attracting attention as a technology for processing this information at high speed and high density. The optical memory element has a feature that it has a higher recording density and can record and reproduce data at higher speed than the currently mainstream magnetic memory element. These optical memory elements include hole formation type, amorphous-crystalline phase transition type, and magnetization reversal type. The hole forming mold is Te, Pb-Te
- A laser beam is applied to a recording film such as Be, which
The method is to drill a hole, record it, and reproduce it by irradiating the hole with a laser beam and detecting it with a photodetector. For this reason, a location once recorded cannot be erased and therefore cannot be rewritten.

There are two types of rewritable devices: phase change type and magnetization reversal type. - An amorphous film such as Te is irradiated with laser light to thermally crystallize and record. Regeneration is performed by detecting the difference in optical properties between amorphous and crystalline materials using a laser beam, and erasure is performed by irradiating a high-power laser beam to melt the crystallized area, and then rapidly cooling it to make it amorphous again. Furthermore, in the magnetization reversal type, recording is performed by irradiating a recording film of GdCo, TbFe, etc. with a laser beam. Then, the magnetism of that location changes thermally, and the light exhibits the Faraday effect and the Kerr effect (the polarization planes of transmitted light and reflected light rotate to become elliptically polarized light).

Recalibration is performed by detecting the presence or absence of the Faraday effect and Kerr effect using a laser beam, and erasing is performed by irradiating the laser beam again to return the magnetism to its initial state. Note that regarding this type of optical memory element, for example, Japanese Patent Laid-Open No. 60
-191449, 60-219654, etc.

[Problem that the invention seeks to solve]

Since the conventional optical memory device described above requires a semiconductor laser for recording and re-correcting signals, it must be equipped with a laser light source and its focus controller.

In addition, the signal response speed (access time) is approximately several hundred meters.
It is s.

The object of the present invention is to achieve an object without using a laser light source.

The object of the present invention is to obtain an optical memory element that can be reproduced with high sensitivity.

[Means for solving problems]

The above object is achieved by providing a high-resistance layer between the semiconductor and the metal in a Schottky barrier type semiconductor device using a semiconductor-metal junction.

[Effect]

A shot barrier type semiconductor element generates photovoltaic force and rectification effect. However, by providing a high resistance layer between the semiconductor and metal of the element, insulation is achieved and no photovoltaic force is generated. Then, when a voltage is applied between the semiconductor and the metal, dielectric breakdown of the high-resistance layer occurs, the semiconductor and the metal become electrically conductive, a Schottky junction is formed, and a photovoltaic force is generated again. By utilizing such a phenomenon, recording can be performed by applying a voltage that destroys the high-resistance layer to an element in which a metal layer, a high-resistance layer, and a semiconductor layer are sequentially laminated.

The location is irradiated with light to detect the presence or absence of photovoltaic force and recalibrate. At this time, the intensity of the light is comparable to that of natural light, and photovoltaic force is generated, so that high-sensitivity reproduction is performed.

〔Example〕

The present invention will be explained in detail below.

FIG. 1 is a sectional view showing the basic structure of the optical memory element of the present invention. A high resistance layer 2 and a metal electrode layer 3 are sequentially provided on a semiconductor substrate 1.

The semiconductor substrate 1 is made of Si, which is a photovoltaic material.

Ge, GaAs, etc. are used for the high resistance layer 2.

SiC, 5isNa, 5iOz, Sin, An
zOaeA Q N , T i Ox, T a g
Use os etc. The high-resistance layer 1 is manufactured by a sputtering method, a CVD method, an MBE method, or the like. The metal electrode layer 3 is formed by a sputtering method, a vapor deposition method, a plating method, etc.
u HAg, AQ, Cu', Mo, Ni, Ti, W, etc. are used. Semiconductor substrate 1 of the device manufactured in the above structure
and the metal electrode layer 3 (for example, a high resistance layer of 100
When a voltage of 2 to 4 V (assuming 0 SiC) is applied, voltage breakdown occurs in the high resistance layer 2, and a Schottky junction is formed between the semiconductor substrate 1 and the metal electrode layer 3 at that location. The Schottky junction exhibits a photovoltaic force and a rectifying effect, but at the location where no voltage is applied, the semiconductor substrate 1 and the metal electrode layer 3 are insulated by the high resistance layer 2, so that the Schottky junction does not exhibit photovoltaic force and rectification. Does not exhibit photovoltaic force or rectification effect due to key junction. By utilizing such a phenomenon, an optical memory element is created in which recording is performed by applying a voltage, and re-reading is performed by irradiating light 4 (natural light, lamp light) near the metal electrode layer 3 and detecting the presence or absence of photovoltaic force. is obtained.

FIG. 2 is a sectional view of an optical memory element in which the semiconductor is formed of a Wl film. A metal electrode layer 3 is formed on the substrate 5. Semiconductor layer 6. High resistance layer 2. Metal electrode layers 3a are sequentially provided. As the substrate 5, glass, plastic, etc. are used, and as for the semiconductor layer 6.

Si, Ge, GaAs, etc. formed by sputtering, CVD, and MBE are used. The metal electrode layer 3a is
Au formed by sputtering method, vapor deposition method, plating method
HA g HA fl p Cu @ M o yN
i, Ti, W, etc. are used. Recording is performed by applying a voltage to the metal electrode layer 3 and metal electrode layer 3a of the element fabricated in the above structure, and re-correction is performed by irradiating light 4 near the metal electrode 3 and detecting the presence or absence of photovoltaic force. An optical memory element that performs this is obtained.

〔Effect of the invention〕

According to the present invention, by using the photovoltaic effect due to the Schottky barrier for recalibration, recalibration can be performed with high sensitivity even with light comparable to natural light. Further, since a laser light source is not required, the cost of the device can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic structure of an optical memory element according to an embodiment of the present invention, and FIG. 2 is a sectional view of an optical memory element in which a semiconductor is formed as a thin film. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 2... High resistance layer, 3... Metal electrode layer, 3a... Metal electrode layer, 4... Light, 5...
Substrate, 6...Semiconductor type l Concave 2 J end 3 Metal 1 layer Light $27

Claims (1)

[Claims] 1. An optical memory element that uses photovoltaic effect due to a Schottky junction between a metal and a semiconductor in a memory element in which reading is performed using light.