JPH0537013A - Injection type light emitting element and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide an injection type light emitting element, in which novel silicon is used. CONSTITUTION:Direct transition type porous silicon 8 has pn junction. The electrodes 10, 11 are arranged on both sides of pn junction of the direct transition type porous silicon 8. Then, inter electrode voltage impression causes injection of a small number of carriers in the direct transition type porous silicon 8 and recrystallization of carriers in the junction part so as to emit light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection type light emitting device.

[0002]

2. Description of the Related Art Hitherto, visible light emitting devices have been realized only by compound semiconductor materials represented by III-V semiconductors.

[0003]

However, the compound semiconductor has a unique high function because of its mechanical brittleness, toxicity, and lack of a stable surface protective film. , Explosive technological progress and application development such as silicon semiconductor devices have not been achieved. Therefore, if it is possible to realize a light emitting device using a silicon semiconductor material, there is no doubt that the rapid evolution of the light emitting device into silicon will be supported by the highly evolved silicon ULSI technology and the innovation of safe and low cost will be achieved. There is no.

An object of the present invention is to provide a novel injection type light emitting device using silicon.

[0005]

A first aspect of the present invention is an injection type device including a direct transition type porous silicon having a pn junction and electrodes arranged on both sides of the pn junction of the direct transition type porous silicon. A light-emitting element will be the gist.

A second aspect of the present invention is the first step of forming a single crystal silicon substrate having a pn junction, and the single crystal silicon substrate including the pn junction is anodized to form a pn junction.
Second Forming Direct Transition Type Porous Silicon With Bonding
The gist of the method is a method of manufacturing an injection type light emitting device, which includes a step and a third step of forming electrodes on the ends of the direct transition type porous silicon and the single crystal silicon substrate, respectively.

[0007]

According to the first invention, when a voltage is applied between the electrodes so that the pn junction is forward biased, minority carriers are directly injected into the transition type porous silicon, and the carriers are recombined at the pn junction. Occurs and emits light.

According to a second aspect of the present invention, a single crystal silicon substrate having a pn junction is formed in the first step, and a single crystal silicon substrate including a pn junction is anodized in the second step to have a pn junction. Direct transition type porous silicon is formed. Further, in the third step, electrodes are formed on the ends of the direct transition type porous silicon and the single crystal silicon substrate, respectively. As a result, the injection type light emitting device of the first invention is manufactured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an injection type light emitting device of this example. 2 to 6 show the manufacturing process.

First, as shown in FIG. 2, an n-type or p-type single crystal silicon substrate 1 is prepared, and the surface layer of the single crystal silicon substrate 1 is made to have a conductivity opposite to that of the substrate by a known ion implantation technique or thermal diffusion technique. A conductive layer 2 of the mold is formed to form a pn junction. Then, the single crystal silicon substrate 1 is washed with a washing liquid (sulfuric acid 4: hydrogen peroxide solution 1).

Subsequently, as shown in FIG. 3, an aluminum electrode plate 3 is arranged on the back surface side of the single crystal silicon substrate 1, and the aluminum electrode plate 3 is covered with an aluminum protective wax 4 so that the surface of the conductive layer 2 is exposed. Cover with. Further, the thus-formed single crystal silicon substrate 1 is dipped in hydrofluoric acid 5 having a concentration of about 25%, and platinum electrodes 6 are arranged facing each other. Then, the single crystal silicon substrate 1
As an anode and a platinum electrode 6 as a cathode to flow a current from a constant current source 7 to anodize the surface portion of the single crystal silicon substrate 1.

This is because O ^2- and OH in hydrofluoric acid 5
⁻ Is attracted to the single crystal silicon substrate 1, electrons on O ²⁻ and OH ⁻ are deprived of the surface of the single crystal silicon substrate 1, and active oxygen is generated. Then, with this active oxygen, S
iO ₂ is formed, and this SiO ₂ is dissolved by hydrofluoric acid 5. The anodization treatment is performed under such a mechanism, and as shown in FIG. 4, the columnar direct transition type porous silicon 8 having a diameter of about 50 Å is formed on the single crystal silicon substrate 1 including the pn junction. To be done. The direct transition type porous silicon 8 has a pn junction. In addition, in FIG.
13 is an ammeter.

When the pn junction is reversely biased, the surface of the silicon substrate 1 may be irradiated with light so that a current necessary for anodization may flow.

Next, the single crystal silicon substrate 1 is immersed in dilute hydrofluoric acid.
Is immersed to directly remove the oxide film remaining on the surface of the transition type porous silicon 8. Subsequently, as shown in FIG. 5, the direct transition type porous silicon 8 is oxidized to form SiO as an insulating filler in the space of the direct transition type porous silicon 8.
Immobilizing meet the ₂ 9. An insulating coating material may be used instead of SiO ₂ .

Further, as shown in FIG. 6, the surface of the direct transition type porous silicon 8 is exposed. Then, as shown in FIG. 1, an electrode 10 made of metal is formed directly on the surface of the transition type porous silicon 8 by a vapor deposition method. This electrode 10
For, a transparent conductive thin film made of ITO, gold, or the like is used.
Further, the electrode 11 is formed on the back surface of the single crystal silicon substrate 1. In FIG. 1, 12 is a direct transition type porous silicon 8
Is a protective film that covers.

Next, the operation of the injection type light emitting device constructed as above will be described. When a forward bias is applied to the pn junction through both electrodes 10 and 11, minority carriers are injected into the respective regions of the direct transition type porous silicon 8 and recombination occurs near the pn junction to emit light. As shown in FIG. 7, the emission wavelength is based on the band-to-band transition of the direct transition type porous silicon 8 (a), the emission based on the recombination of the donor electron and the free hole (b), the free electron and the acceptor hole. Emissions (c) based on the recombination of the above can be obtained individually or in combination.

As described above, in this embodiment, the single crystal silicon substrate 1 having the pn junction is formed (first step), and the single crystal silicon substrate 1 including the pn junction is subjected to anodization treatment to have the pn junction. The direct transition type porous silicon 8 was formed (second step), and the electrodes 10 and 11 were formed on the end portion of the direct transition type porous silicon 8 and the single crystal silicon substrate 1 (third step).

As a result, the direct transition type porous silicon 8 having a pn junction and the pn of the direct transition type porous silicon 8 are formed.
An injection type light emitting device is manufactured with electrodes 10 and 11 arranged on both sides of the junction. In this element, minority carriers are directly injected into the transition type porous silicon 8 by applying a voltage between the electrodes, and carriers are recombined at the pn junction to emit light. In this way, a novel injection type light emitting device using silicon can be obtained.

Further, since the space of the direct transition type porous silicon 8 is filled with and fixed by SiO ₂ 9 (insulating filler), the strength of the direct transition type porous silicon 8 can be increased.

[0020]

As described above in detail, according to the present invention,
It exhibits an excellent effect of being able to provide an injection type light emitting device using a novel silicon.

[Brief description of drawings]

FIG. 1 is a diagram showing an injection type light emitting device of an example.

FIG. 2 is a manufacturing process diagram of an injection type light emitting device.

FIG. 3 is a manufacturing process diagram of an injection type light emitting device.

FIG. 4 is a manufacturing process diagram of an injection type light emitting device.

FIG. 5 is a manufacturing process diagram of an injection type light emitting device.

FIG. 6 is a manufacturing process diagram of an injection type light emitting device.

FIG. 7 is an energy band diagram.

[Explanation of symbols]

1 Single Crystal Silicon Substrate 8 Direct Transition Type Porous Silicon 9 SiO ₂ 10 Insulating Filler 11 Electrode

Claims (3)

[Claims] 1. An injection type light emitting device comprising: a direct transition type porous silicon having a pn junction; and electrodes arranged on both sides of the pn junction of the direct transition type porous silicon. 2. The injection type light emitting device according to claim 1, wherein the space of the direct transition type porous silicon is filled with an insulating filler and fixed. 3. A first step of forming a single crystal silicon substrate having a pn junction, and anodizing the single crystal silicon substrate including the pn junction to form a direct transition type porous silicon having a pn junction. 2. A method of manufacturing an injection type light emitting device, comprising: a second step of forming; and a third step of forming electrodes on the ends of the direct transition type porous silicon and the single crystal silicon substrate, respectively.