JPH06283754A - Light emitting element - Google Patents

Abstract

PURPOSE:To provide a light emitting element using polycrystalline silicon, especially, a light emitting element which emits a light by injecting charges, using p-n junction. CONSTITUTION:A high-speed thermal oxide porous silicon layer 13 is made on a p-type single crystalline silicon substrate 12, and an amorphous silicon carbon alloy 14 containing n-type fine crystals is stacked on the high-speed porous silicon layer 13. By constituting this element as mentioned above, a p-n junction type of light emitting element using silicon can be materialized. Moreover, a light emitting element, which can prevent the drop of the efficiency of light emission, can be provided by using high-speed thermal oxide polycrystalline silicon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device which can be used for optical communication, a self-luminous display, a light source, an optical integrated circuit and the like.

[0002]

2. Description of the Related Art Since a silicon semiconductor is an indirect transition semiconductor, it is considered impossible to manufacture a light emitting device. The light emitting device is a III-V group compound semiconductor, a II-VI group compound semiconductor, and an IV-group compound semiconductor. It was made of VI compound semiconductors. However, silicon semiconductors have more resources and are cheaper than compound semiconductors. In particular, polycrystalline silicon can be manufactured on a large area on various substrates such as stainless steel substrates, quartz substrates, and glass substrates at low cost. . In addition, due to the advantage that device design / fabrication technology is high and it is difficult to realize with the current compound semiconductors, it is possible to build highly integrated and highly reliable logic, operation, drive, light receiving element, etc. on the same substrate. It has been earnestly desired to realize a light emitting device using silicon.

However, in 1990, L. T. Canh
am showed that porous silicon obtained by anodizing single-crystal silicon in a hydrofluoric acid solution exhibits strong photoluminescence at room temperature (Applied Physics L).
etters 57, 1990, p. 1046). This indicates that there is a possibility that a light emitting device can be realized even with silicon, and thereafter, the mechanism of this photoluminescence generation was actively studied.

[0004]

As a light emitting device using this porous silicon, there is Japanese Patent Application No. 4-34507. Conventional light emitting devices using porous silicon emit light from red to orange. However, none of them emitted blue light. Further, the conventional light emitting element was observed to have a decrease in light emission luminance during operation.

The present invention has been made under the above circumstances, and an object thereof is to provide a light emitting element using silicon, particularly a blue light emitting element. Further, it is intended to realize a light emitting element in which a decrease in emission luminance is small during operation.

[0006]

In order to solve the above-mentioned problems, the light-emitting device according to the present invention is characterized in that porous silicon formed on p-type or n-type single crystal silicon is thermally oxidized at high speed. It is characterized by using the rapid thermal oxidation porous silicon produced by.

The light emitting device according to the second aspect of the present invention uses the rapid thermal oxidation porous silicon produced by rapid thermal oxidation of the porous silicon formed on the p-type or n-type polycrystalline silicon. It is characterized by.

According to a third aspect of the present invention, there is provided a light emitting device having a high thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on p-type or n-type single crystal silicon, and a conduction different from that of the single crystal silicon. It is characterized by using a pn junction made of a semiconductor having a mold.

According to a fourth aspect of the present invention, there is provided a light emitting device, wherein high-speed thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on p-type or n-type polycrystalline silicon and conduction different from that of the polycrystalline silicon. It is characterized by using a pn junction made of a semiconductor having a mold.

A light emitting device according to a fifth aspect of the invention is characterized in that, in the third or fourth aspect of the invention, the semiconductor layer is an amorphous silicon carbon alloy containing microcrystals.

A light emitting device according to a sixth aspect of the present invention is the light emitting device according to the third or fourth aspect, wherein the semiconductor layer is an amorphous silicon carbon alloy.

A light emitting device according to a seventh aspect of the present invention is characterized in that, in the third or fourth aspect of the invention, the semiconductor layer uses amorphous silicon containing microcrystals.

In the light emitting device according to the present invention, the indium tin oxide is formed on the rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of the porous silicon formed on the p-type or n-type single crystal silicon. It is characterized by that.

According to a ninth aspect of the light-emitting device of the present invention, indium tin oxide is formed on rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on p-type or n-type polycrystalline silicon. It is characterized by that.

A light emitting device according to a tenth aspect of the invention is characterized in that, in the eighth or ninth aspect of the invention, Au is used instead of indium tin oxide.

[0016]

In order to manufacture a blue light emitting device, its light emitting layer has an energy band gap (about 2.5e) wider than that of blue.
V or more), and the electrons and holes must be radiatively recombined. In order to easily confirm that this requirement is satisfied, it is sufficient to measure photoluminescence due to ultraviolet light excitation and confirm that it emits blue light. If this phenomenon can be confirmed, a blue light emitting device can be realized by injecting electrons and holes into the light emitting layer by some means and causing recombination in the light emitting layer. The present inventors have found that rapid thermal oxidation porous silicon produced by rapid thermal oxidation of porous silicon in a rapid thermal oxidation furnace emits blue light when excited by ultraviolet light. Further, they have found a means for injecting holes and electrons into the light emitting layer and recombining them in the light emitting layer.

The present inventors have conducted an anodization method (ethyl alcohol: fluorine) on a p-type or n-type single crystal silicon substrate (plane orientation (111) and (100), resistivity 0.05 to 50 Ωcm). Acid (48% aqueous solution) = 0: 1 to 10: 1
Current density: 1 mA / c by connecting single crystal silicon to the anode side and an electrode such as platinum to the cathode side in the aqueous solution of
A current of m ^{2 to} 200 mA / cm ² is applied and a treatment of single crystal silicon is performed for 30 seconds to 10 minutes to prepare a porous silicon (porous Si) layer, and then the porous silicon layer is formed. Rapid thermal oxidation (800 ° C to 1200 ° C in oxygen or oxygen and nitrogen atmosphere)
Thermal oxidation is performed at 10 ° C. for 10 seconds to 120 seconds. It was found that the rapid thermal oxidation porous silicon layer produced by the above) exhibits strong blue photoluminescence when excited by ultraviolet light. In addition, a wide band gap (2.0 to 2.4) having a conductivity type different from that of the single crystal silicon substrate on which the rapid thermal oxidation porous silicon is manufactured is provided on the rapid thermal oxidation porous silicon.
eV) and an amorphous silicon carbon alloy containing microcrystals having a high conductivity (10 ⁻² to 10 ¹ S / cm) (μ
It has been found that a good pn junction can be obtained by depositing c-SiC). It was also found that a good pn junction can be obtained by the same method when a rapid thermal oxidation porous silicon is produced by using a p-type or n-type polycrystalline silicon substrate instead of a single crystal silicon substrate.

In order to produce a good pn junction that emits light from an LED, a method for producing a rapid thermal oxidation porous silicon layer (resistivity of substrate, anodization method, temperature of fast thermal oxidation furnace, atmosphere, oxidation). Time, etc.), especially, the amorphous material containing microcrystals so as not to damage the interface characteristics between the rapid thermal oxidation porous silicon layer and the amorphous silicon carbon alloy film containing microcrystals. It is very important to optimize the deposition conditions of silicon carbon alloy.

The inventors of the present invention have conducted diligent research on these, and as a result, by the anodization method, ethyl alcohol: hydrofluoric acid (48% aqueous solution) = 0.1: 1 to 5: 1, current density 5
˜50 mA / cm ² , plane orientation (111) and (100), anodization time 1 to 5 minutes, resistivity 0.1 to 40 Ω
cm-type p-type single crystal silicon substrate, and a porous silicon layer is formed on the surface of the p-type single crystal silicon substrate.
The conditions for producing a rapid thermal oxidation porous silicon layer capable of injecting holes from the p-type single crystal silicon substrate into the rapid thermal oxidation porous silicon layer by thermal oxidation for 60 seconds were found.

Further, electron cyclotron resonance plasma C
Gas pressure of 0.001 to 0.008 Torr by VD method,
Substrate temperature 150-350 ° C, input power 200-350
_{W, SiH 4: CH 4:} PH 3: H 2 = 1: 1~3:
At 0.005 to 0.03: 100 to 200, an amorphous silicon carbon alloy film containing n-type crystallites is formed on the surface of the rapid thermal oxidation porous silicon layer to form n-type crystallites. The deposition conditions of the amorphous silicon carbon alloy containing n-type microcrystals capable of favorably injecting electrons from the contained amorphous silicon carbon alloy film into the rapid thermal oxidation porous silicon layer were found. As a result, a blue light emitting element was realized.

Further, this light emitting element not only emits blue light, but also has a very small decrease in luminous efficiency. This is because porous silicon is generally terminated with hydrogen, but hydrogen is unstable with respect to heat and is easily separated from porous silicon, while oxygen is stable with respect to heat and the like. This is because it is difficult to separate from the porous silicon, and by replacing the hydrogen terminating the porous silicon with oxygen, it is possible to prevent the deterioration of the light emission characteristics caused by the dangling bond of the porous silicon.

Regarding the conditions for manufacturing a light emitting device using an n-type single crystal silicon substrate, a rapid thermal oxidation porous silicon layer capable of favorably injecting electrons from the n type single crystal silicon substrate into the rapid thermal oxidation porous silicon layer. Manufacturing conditions of, except that light must be irradiated during the anodization,
The same conditions as in the case of using a p-type single crystal silicon substrate, and p-type capable of favorably injecting holes from the amorphous silicon carbon alloy film containing p-type microcrystals into the rapid thermal oxidation porous silicon layer As for the deposition conditions of the amorphous silicon carbon alloy containing the microcrystals, except that B ₂ H ₆ is used as the source gas in place of PH ₃ , the amorphous silicon carbon alloy containing the n-type microcrystals is used. It was found that the deposition conditions were the same.

Further, regarding the conditions for manufacturing a light emitting device using p-type polycrystalline silicon, a high-speed thermally-oxidized porous silicon layer capable of favorably injecting holes from p-type polycrystalline silicon into the rapid-thermally oxidized porous silicon layer is provided. The manufacturing conditions are the same as those using the p-type single crystal silicon substrate, except that light must be irradiated during anodization.
It was also found that the conditions for manufacturing a light emitting element using n-type polycrystalline silicon are the same as the conditions for using an n-type single crystal silicon substrate.

It has been found by the inventors that when the resistivity of single crystal silicon exceeds 40 Ωcm, the resistance of the substrate becomes high, and the charge is not well injected from the substrate into the rapid thermal oxidation porous silicon. It was found that it was not possible to fabricate such a light emitting device. Regarding the resistivity of the polycrystalline silicon, since the polycrystalline silicon is used as a thin film, the junction in which the electric charge is injected from the polycrystalline silicon to the rapid thermal oxidation porous silicon until the resistivity of the polycrystalline silicon is up to 10 ⁶ Ωcm. It turned out to be obtained.

Further, when the porous silicon layer is formed by the anodization method, if the ratio of ethyl alcohol and hydrofluoric acid is less than 0.1: 1 of ethyl alcohol: hydrofluoric acid, bubbles are generated during the anodization and the porosity is increased. It was found that a good light emitting device could not be produced because the quality silicon could not be made uniform, and when the current density exceeded 50 mA / cm ² , silicon electropolishing gradually began to occur.

Further, when an amorphous silicon carbon alloy film containing fine crystals is formed by the electron cyclotron resonance plasma CVD method, the gas pressure is 0.001 Tor.
If it is less than r, the underlying rapid thermal oxidation porous silicon layer is damaged by the etching effect, and if it exceeds 0.008 Torr, the plasma is not stabilized and an amorphous silicon carbon alloy containing fine crystals cannot be produced. It was found that a good light emitting element could not be manufactured.

If the substrate temperature is lower than 150 ° C., an amorphous silicon carbon alloy containing microcrystals cannot be produced. If the substrate temperature exceeds 350 ° C., the surface state of the rapid thermal oxidation porous silicon layer changes and no light is emitted. Therefore, it was found that a favorable light-emitting element could not be manufactured.

Further, in the rapid thermal oxidation of the porous silicon layer to produce the rapid thermal oxidation porous silicon layer, most of the hydrogen terminating the porous silicon is converted into oxygen when the thermal oxidation time is less than 10 seconds. Cannot be replaced,
It was found that when the time exceeds 120 seconds, the structure of the porous silicon changes, so that good light emission is not exhibited, and as a result, a light emitting device cannot be manufactured.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is a schematic structural diagram of a light emitting device using p-type single crystal silicon which is a first embodiment of the present invention. FIG. 5 is a diagram for explaining a method for producing porous silicon by the anodization method. FIG. 7 shows FIG.
Indium tin oxide (IT
It is a figure showing an emission spectrum when a positive voltage of 30V is applied to the (O) side.

In the light emitting device 1 shown in FIG. 1, Al 11 is vapor-deposited on the back surface of the p-type single crystal silicon substrate 12, and the rapid thermal oxidation porous silicon layer 1 is formed on the surface of the p-type single crystal silicon substrate 12.
3 is formed, and n is formed on the rapid thermal oxidation porous silicon layer 13.
Type amorphous carbon-carbon alloy film 1 containing microcrystals
4 is formed on the amorphous silicon carbon alloy film 14 containing n-type microcrystals, and ITO1 is formed as a transparent electrode.
5 is formed.

A method of manufacturing the light emitting device 1 shown in FIG. 1 will be described. First, the p-type single crystal silicon substrate 12 ((10
0) surface, Al11 on the back surface with a resistivity of 0.2 to 10 Ωcm)
Is vapor-deposited to form an ohmic contact to produce a first intermediate product.

Next, as shown in FIG. 5, the first intermediate product is covered with wax on the surface of the p-type single crystal silicon substrate 12 except for the portion to be made porous, and the platinum electrode Pt is connected to the cathode side. , Al11 is connected to the anode side, and the platinum electrode P
t and the first intermediate product as ethyl alcohol: hydrofluoric acid (48
% Aqueous solution) = 1: 1 solution (C ₂ H ₅ OH + HF + H
₂ O). Use a constant current power source to increase the current density to 10
A porous silicon layer is prepared by fixing at -30 mA / cm ² and anodizing for about 3 to 5 minutes to prepare a second intermediate product.

After the wax adhering to the surface of the second intermediate product is thawed with an organic solvent, Al is etched, and washed with pure water, the porous silicon layer formed on the p-type single crystal silicon substrate 12 is treated with oxygen or oxygen. 800 ° C to 1200 ° C using a high-speed infrared irradiation device in an oxygen and nitrogen atmosphere
By rapid thermal oxidation for 10 seconds to 120 seconds, a rapid thermal oxidation porous silicon layer 13 is produced, and a third intermediate product is produced. After that, again Al11 is vapor-deposited on the back surface of the P-type single crystal silicon substrate 12 to make ohmic contact.

The third intermediate product is placed in an electron cyclotron resonance plasma CVD apparatus, and an amorphous silicon carbon alloy containing n-type microcrystals is deposited on the rapid thermal oxidation porous silicon layer 13 by 150 angstroms. An amorphous silicon carbon alloy film 14 containing microcrystals of the mold is prepared, and a fourth intermediate product is prepared. The deposition conditions are gas pressure 0.005 to 0.008 Torr, input power 300 W,
_{SiH 4: CH 4: PH 3} : H 2 = 1: 1~3: 0.0
05-0.03: 100-200, substrate temperature 300 degreeC.

Using an electron beam evaporation apparatus, ITO 15 is deposited as a transparent electrode on the amorphous silicon carbon alloy film 14 containing the n-type microcrystals of the fourth intermediate product to a thickness of 600 angstrom to manufacture the light emitting device 1. .

As shown in FIG. 7, the emission spectrum when a negative voltage of 30 V was applied to the ITO 15 side had an emission wavelength of about 400 to 600 nm and a peak wavelength of 450 nm.

According to the first embodiment of the present invention, an amorphous silicon carbon alloy film containing a rapid thermal oxidation porous silicon layer 13 formed on a p-type single crystal silicon substrate 12 and n-type microcrystals. Since the pn junction consisting of 14 is used, holes are rapidly emitted from the p-type single crystal silicon substrate 12 and electrons are emitted from the amorphous silicon carbon alloy film 14 containing n-type microcrystals. Can be injected well. Further, the light emitting element of this embodiment is a blue light emitting element as shown in FIG.

Further, since the porous silicon layer which is the light emitting layer is subjected to rapid thermal oxidation to form the rapid thermal oxidation porous silicon layer 13, the hydrogen terminating the porous silicon can be replaced with oxygen. As a result, it is possible to prevent the luminous efficiency from decreasing due to heat or the like.

Next, a second embodiment of the present invention will be described with reference to FIGS. 2, 6 and 8. FIG. 2 is a schematic structural diagram of a light emitting device using n-type single crystal silicon which is a second embodiment of the present invention. FIG. 6 is a diagram for explaining a method for producing porous silicon by the anodization method. FIG. 8 is a diagram showing an emission spectrum when a positive voltage of 40 V is applied to the ITO side of the light emitting element shown in FIG.

In the light emitting device 2 shown in FIG. 2, Al 21 is vapor-deposited on the back surface of the n-type single crystal silicon substrate 22, and the rapid thermal oxidation porous silicon layer 2 is formed on the surface of the n-type single crystal silicon substrate 22.
3 is formed, and p is formed on the rapid thermal oxidation porous silicon layer 23.
-Type amorphous silicon carbon alloy film 2 containing microcrystals
4 is formed on the amorphous silicon carbon alloy film 24 containing p-type microcrystals, and ITO 2 is formed as a transparent electrode.
5 is formed. As shown in FIG. 6, the method for manufacturing the light-emitting element 2 is such that, when performing anodization, the surface of the n-type single crystal silicon substrate 22 on which porous silicon is to be produced is irradiated with tungsten lamp light, and electron cyclotron resonance plasma is used. The conditions for depositing an amorphous silicon carbon alloy containing p-type microcrystals on the rapid thermal oxidation porous silicon layer 23 using a CVD apparatus are SiH ₄ : CH ₄ : B _{2
H 6: H 2 = 1:} 1~3: 0.005~0.03: 10
Since it is the same as the first embodiment except that it is 0 to 200, detailed description thereof will be omitted.

The emission spectrum when a positive voltage of 40 V was applied to the ITO 25 side had an emission wavelength of about 400 to 600 nm and a peak wavelength of 445 nm, as shown in FIG.

According to the second embodiment of the present invention, an amorphous silicon carbon alloy film containing a p-type microcrystal and a rapid thermal oxidation porous silicon layer 23 formed on an n-type single crystal silicon substrate 22. Since a pn junction made of 24 is used, electrons are emitted from the n-type single crystal silicon substrate 22 and holes are emitted from the amorphous silicon carbon alloy film 24 containing p-type microcrystals. Can be injected well. Other effects are similar to those of the first embodiment.

Next, the third embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. FIG. 3 is a schematic structural diagram of a light emitting device using p-type single crystal silicon which is a third embodiment of the present invention.

In the light emitting device 3 shown in FIG. 3, Al 31 is vapor-deposited on the back surface of the p-type single crystal silicon substrate 32, and the rapid thermal oxidation porous silicon layer 3 is formed on the surface of the p type single crystal silicon substrate 32.
3 is formed on the rapid thermal oxidation porous silicon layer 33.
Type amorphous silicon carbon alloy (a-SiC) film 34
And the ITO 35 is formed as a transparent electrode on the n-type amorphous silicon carbon alloy film 34. The light emitting element 3 is manufactured by using a normal plasma CVD method without using an electron cyclotron resonance plasma CVD apparatus.
Since an n-type amorphous silicon carbon alloy film can be formed on the rapid thermal oxidation porous silicon layer 33 by using the apparatus, the detailed description thereof is omitted because it is similar to the first embodiment. To do.

According to the third embodiment of the present invention, the n-type amorphous silicon carbon alloy film 34 can be formed on the rapid thermal oxidation porous silicon layer 33 by using an ordinary plasma CVD apparatus. Thus, the light emitting device can be manufactured more easily than in the first embodiment. However, amorphous silicon carbon has a conductivity of 10 ⁻⁵ S at a band gap of 2.0 eV.
/ Cm, which is lower in both bandgap and conductivity than the amorphous silicon carbon alloy containing microcrystals, and thus the emission luminance is slightly lower than that of the light emitting device shown in the first embodiment. Other effects are similar to those of the first embodiment.

In the third embodiment, the rapid thermal oxidation porous silicon layer 33 is formed on the surface of the p-type single crystal silicon substrate 32, and the n-type amorphous is formed on the rapid thermal oxidation porous silicon layer 33. Although the silicon-carbon alloy film 34 is formed, the present invention is not limited to this, and a rapid thermal oxidation porous silicon layer is formed on the surface of an n-type single crystal silicon substrate, and p is formed on the rapid thermal oxidation porous silicon layer. A type of amorphous silicon carbon alloy film may be formed.

Instead of the amorphous silicon carbon alloy film, an amorphous silicon (μc-Si) film containing fine crystals may be used. However, even amorphous silicon containing microcrystals cannot be made to have higher conductivity in a place where the bandgap is wider than that of amorphous silicon carbon alloy containing microcrystals, so amorphous silicon carbon alloy was used. Similar to the case, the emission brightness is slightly lower than that of the light emitting device shown in the first embodiment.

Next, the fourth embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. FIG. 4 is a structural diagram of a light emitting device using p-type single crystal silicon according to a fourth embodiment of the present invention.

In the light emitting device 4 shown in FIG. 4, Al 41 is vapor-deposited on the back surface of the p-type single crystal silicon substrate 42, and the rapid thermal oxidation porous silicon layer 4 is formed on the surface of the p type single crystal silicon substrate 42.
3 is formed, and I is formed on the rapid thermal oxidation porous silicon layer 43.
The TO44 is directly formed. The manufacturing method of the light-emitting element 4 is different from that of the method of manufacturing an amorphous silicon carbon alloy containing n-type microcrystals on a porous silicon layer by using an electron cyclotron resonance plasma CVD apparatus, except that Since it is similar to the first embodiment, detailed description thereof will be omitted.

According to the fourth embodiment of the present invention, since the ITO 44 is directly formed on the rapid thermal oxidation porous silicon layer 43, the structure of the light emitting device can be simplified as compared with the first embodiment. However, the emission brightness is slightly lower than that of the light emitting device shown in the first embodiment. Other effects are similar to those of the first embodiment.

In the fourth embodiment, the rapid thermal oxidation porous silicon layer 43 is formed on the surface of the p-type single crystal silicon substrate 42, and the ITO 44 is formed on the rapid thermal oxidation porous silicon layer 43.
However, the present invention is not limited to this, and the rapid thermal oxidation porous silicon layer is formed on the surface of the n-type single crystal silicon substrate, and the ITO is directly formed on the rapid thermal oxidation porous silicon layer. It may be one.

Au may be used instead of ITO. However, as in the case of using ITO, the light emission luminance is slightly lower than that of the light emitting device shown in the first embodiment.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made within the scope of the invention. For example, in each of the above embodiments, p-type or n-type
A rapid thermal oxidation porous silicon layer was produced by rapid thermal oxidation of a porous silicon layer formed on a die-type single crystal silicon substrate, but the present invention is not limited to this. Even if a rapid thermal oxidation porous silicon layer is produced by rapid thermal oxidation of a porous silicon layer formed on a p-type or n-type polycrystalline silicon layer formed on a substrate or the like by a low pressure CVD method or the like. Good. When a light-emitting element is manufactured using polycrystalline silicon, a large-area one can be manufactured at lower cost than when a light-emitting element is manufactured using a single crystal silicon substrate cut out from a pure silicon wafer.

[0054]

As described above, according to the first aspect of the present invention, the energy band gap of the porous silicon formed on the p-type or n-type single crystal silicon is increased by rapid thermal oxidation. At about 2.5 eV or more, high-speed thermally oxidized porous silicon in which electrons and holes are radiatively recombined can be produced, and thus a light emitting device capable of emitting blue light can be provided.

According to the second aspect of the invention, the p-type or n-type
-Speed thermal oxidation of porous silicon formed on p-type polycrystalline silicon to produce high-speed thermally oxidized porous silicon with an energy band gap of approximately 2.5 eV or more and in which electrons and holes are radiatively recombined. Therefore, a light emitting element capable of emitting blue light can be provided. In addition, by using rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on polycrystalline silicon, high speed thermal oxidation porous silicon produced on a single crystal silicon substrate cut from a pure silicon wafer. A light-emitting element which has a large area and can be manufactured at low cost as compared with a light-emitting element manufactured using silicon can be provided.

According to the invention of claim 3, a p-type or n-type
Rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of the porous silicon formed on the single crystal silicon of the type and a semiconductor having a conductivity type different from that of the single crystal silicon. Holes and electrons can be injected into and recombined with each other, whereby a light emitting element capable of emitting blue light can be provided.

According to the invention of claim 4, a p-type or an n-type
4. The invention according to claim 3, wherein a pn junction made of a rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on a polycrystalline silicon of a type and a semiconductor having a conductivity type different from that of the polycrystalline silicon is used. In addition, to provide a light-emitting element that can be manufactured in a large area at low cost compared to a light-emitting element manufactured using high-speed thermally oxidized porous silicon that is manufactured in a single crystal silicon substrate shape cut from a pure silicon wafer. You can

According to the invention of claim 5, in the invention of claim 3 or 4, since the semiconductor is made of an amorphous silicon carbon alloy containing microcrystals, the effect of the invention of claim 3 or 4 In addition, holes and electrons can be favorably injected and recombined into the rapid thermal oxidation porous silicon that is the light emitting layer, and therefore, good p
A light emitting device having an n-junction structure can be provided.

According to the invention of claim 6, in the invention of claim 3 or 4, since the semiconductor is made of an amorphous silicon carbon alloy, in addition to the effect of the invention of claim 3 or 4, It is possible to manufacture a light emitting element by using the plasma CVD apparatus described in (1) above, and thus it is possible to provide a light emitting element that is easy to manufacture and inexpensive.

According to the invention of claim 7, in the invention of claim 3 or 4, since the semiconductor uses amorphous silicon containing microcrystals, the effect of the invention of claim 3 or 4 can be obtained. In addition, a light emitting element can be manufactured by using a normal plasma CVD apparatus, and thus a light emitting element which is easy to manufacture and inexpensive can be provided.

According to the invention of claim 8, p-type or n-type
Since ITO is directly formed on the rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of the porous silicon formed on the mold single crystal silicon, a light emitting device having a simple structure can be provided.

According to the invention of claim 9, p-type or n-type
Since ITO is directly formed on the rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of the porous silicon formed on the polycrystalline silicon of the mold, a light emitting device having a simple structure can be provided.

According to the tenth aspect of the present invention, Au is directly deposited on the rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of the porous silicon formed on the p-type or n-type single crystal or polycrystalline silicon. Since it is formed, a light emitting device having a simple structure can be provided.

Further, according to the above-mentioned invention, since the rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of the porous silicon is used for the light emitting layer, the deterioration of the emission characteristics of the porous silicon due to the dangling bond is prevented. Therefore, it is possible to provide a light emitting element capable of preventing a decrease in luminous efficiency.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of a light emitting device using p-type single crystal silicon which is a first embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a light emitting device using n-type single crystal silicon which is a second embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a light emitting device using p-type single crystal silicon which is a third embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a light emitting device using p-type single crystal silicon according to a fourth embodiment of the present invention.

FIG. 5 is a diagram for explaining a method for producing porous silicon by anodizing.

FIG. 6 is a diagram for explaining a method for producing porous silicon by anodization.

FIG. 7 is a diagram showing an emission spectrum when a negative voltage of 30 V is applied to the ITO side of the light emitting device shown in FIG.

8 is a diagram showing an emission spectrum when a positive voltage of 40 V is applied to the ITO side of the light emitting device shown in FIG.

[Explanation of sign]

1,2,3,4 Light emitting element 11,21,31,41 Al 12,32,42 p-type single crystal silicon substrate 13,23,33,43 Fast thermal oxidation porous silicon layer 14 Contains n-type microcrystals Silicon carbon alloy film 15, 25, 35, 44 ITO 22 n-type single crystal silicon substrate 24 silicon carbon alloy film containing p-type microcrystals 34 n-type amorphous silicon carbon alloy film

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[Procedure amendment]

[Submission date] June 18, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

A method of manufacturing the light emitting device 1 shown in FIG. 1 will be described. First, the p-type single crystal silicon substrate 12 ((10
0) surface, Al11 on the back surface having a resistivity of 0.1 to 10 Ωcm)
Is vapor-deposited to form an ohmic contact to produce a first intermediate product.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

The third intermediate product is placed in an electron cyclotron resonance plasma CVD apparatus, and an amorphous silicon carbon alloy containing n-type microcrystals is deposited on the rapid thermal oxidation porous silicon layer 13 by 100 to 600 angstrom. As a result, an amorphous silicon carbon alloy film 14 containing n-type microcrystals is produced, and a fourth intermediate product is produced. The deposition conditions are gas pressure of 0.005 to 0.008 Torr and input power of 30.
_{0W, SiH 4: CH 4:} PH 3: H 2 = 1: 1~3:
0.005-0.03: 100-200, substrate temperature 30
It is 0 ° C.

Claims (10)

[Claims] 1. A light emitting device comprising a rapid thermal oxidation porous silicon produced by rapid thermal oxidation of porous silicon formed on p-type or n-type single crystal silicon. 2. A light emitting device comprising a rapid thermal oxidation porous silicon produced by rapid thermal oxidation of porous silicon formed on p-type or n-type polycrystalline silicon. 3. A rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on p-type or n-type single crystal silicon and a pn junction made of a semiconductor having a conductivity type different from that of the single crystal silicon. A light emitting element characterized by being used. 4. A pn junction composed of rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on p-type or n-type polycrystalline silicon and a semiconductor having a conductivity type different from that of the polycrystalline silicon. A light emitting element characterized by being used. 5. The semiconductor according to claim 3, comprising an amorphous silicon carbon alloy containing microcrystals.
Alternatively, the light-emitting element according to item 4. 6. The light emitting device according to claim 3, wherein the semiconductor is made of an amorphous silicon carbon alloy. 7. The light emitting device according to claim 3, wherein the semiconductor is amorphous silicon containing microcrystals. 8. A light emitting device comprising indium tin oxide formed on rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on p-type or n-type single crystal silicon. 9. A light emitting device characterized in that indium tin oxide is formed on rapid thermal oxidation porous silicon obtained by rapid thermal oxidation of porous silicon formed on p-type or n-type polycrystalline silicon. 10. The light emitting device according to claim 8, wherein Au is used in place of the indium tin oxide.