KR20050009049A - Semiconductor-emitting device and method for manufacturing thereof - Google Patents

Abstract

PURPOSE: A semiconductor-emitting device and a fabricating method thereof are provided to remove hydrogen elements included in a p-type semiconductor layer and improve the emitting efficiency by using thermally split gases. CONSTITUTION: A first semiconductor layer and a second semiconductor layer are sequentially formed on a substrate. A hydrogen removal process is performed to remove hydrogen included in the second semiconductor layer by using ammonia and nitric acid. The hydrogen removal process includes a thermal splitting process of the ammonia and the nitric acid and a thermal process for reacting the thermally split gases with the residual hydrogen included in the second semiconductor layer.

Description

Semiconductor light emitting device and method for manufacturing the same

The present invention relates to a semiconductor light emitting device, and more particularly to a method for manufacturing a semiconductor light emitting device that can improve the luminous efficiency by recombination of electrons and holes by removing the hydrogen present in the P-type semiconductor layer.

In particular, the present invention can be applied to nitride semiconductor light emitting devices.

BACKGROUND ART In recent years, nitride semiconductor light emitting devices have been spotlighted as materials such as blue light emitting diodes (LEDs), blue laser diodes (LDs), or solar cells.

Among them, short wavelength blue-blue LD in the 400 nm range with respect to red AlGaAs LD in the 800-830 nm wavelength range makes it possible to increase the information recording density by four times or more, and is widely used as a light source for digital versatile discs (DVDs).

1 is a view showing a conventional GaN-based semiconductor light emitting device.

Referring to FIG. 1, the conventional GaN semiconductor light emitting device includes a substrate 1, a buffer layer 2, and an N-type GaN 3 sequentially formed on the substrate 1. ), An active layer (4) and a P-type semiconductor layer (P-type GaN, 5). Although not shown in FIG. 1, a cladding layer may be formed on the buffer layer 2 and the P-type semiconductor layer 5. In addition, a P-type and an N-type electrode may be formed on the lower portion of the substrate 1 and on the P-type semiconductor layer 5 to apply current.

Al ₂ O ₃ , SiC, ZnO, Si, or the like may be used as the substrate 1. The buffer layer 2 is generally formed by depositing GaN on the substrate using metal organic chemical vapor deposition (MOCVD).

In particular, the P-type semiconductor layer 5 is doped to P-type mainly using Mg dopant.

In the conventional semiconductor light emitting device as described above, when the predetermined semiconductor layer is formed to form the P-type semiconductor layer 5, the Mg dopant is simultaneously doped, thereby forming the P-type semiconductor layer 5.

However, when Mg is doped to form the P-type semiconductor layer 5, Mg is combined with the hydrogen (H) component of the ammonia (NH ₃ ) gas to form an Mg-H conjugate having electrical insulating properties. . That is, after the P-type semiconductor layer 5 is formed, N-vacancy is formed on the surface of the P-type semiconductor layer 5 by out-diffusion of nitrogen at the time of temperature cooling. To prevent this, ammonia is maintained. At this time, the hydrogen component generated by pyrolysis from ammonia penetrates into the inside through the surface of the P-type semiconductor layer 5. And the hydrogen components so infiltrated are connected to Mg-H conjugated with doped Mg. As described above, the Mg bonded by the hydrogen component cannot freely move, and thus, recombination with electrons doped in the N-type semiconductor layer is prevented. As a result, the recombination rate between holes and electrons due to Mg decreases, thereby reducing the luminous efficiency. In addition, since the Mg-H combination has a high resistance of several MΩ or more, a problem arises in that power consumption increases as more driving voltages are applied to achieve a predetermined luminous efficiency.

Accordingly, the present invention has been made to solve the above problems, by removing the hydrogen present in the P-type semiconductor layer using ammonia and nitric acid to increase the recombination rate of holes and electrons to improve the luminous efficiency. An object of the present invention is to provide a semiconductor light emitting device and a method of manufacturing the same.

1 is a view showing a conventional GaN semiconductor light emitting device.

2 is a view showing a heat treatment apparatus used to manufacture a semiconductor light emitting device according to an embodiment of the present invention.

According to a preferred embodiment of the present invention for achieving the above object, a method of manufacturing a semiconductor light emitting device, comprising the steps of sequentially forming a first semiconductor layer, an active layer and a second semiconductor layer on a substrate; And removing a large amount of hydrogens present in the second semiconductor layer using ammonia and nitric acid.

Removing the hydrogens may include thermally decomposing the ammonia and the nitric acid, respectively; And heat treating the thermally decomposed gas gases to react with the hydrogen present in the second semiconductor layer.

The thermally decomposed gas gases may be composed of H ₂ , N ₂ , and O ₂ .

The ammonia and the nitric acid may be thermally decomposed into the gas gases in the temperature range of 500 ~ 1000 ℃.

The thermally decomposed gas gases may be heat treated at a temperature in a range of 500 ° C. to 800 ° C. to react with hydrogens present in the second semiconductor layer.

The gas gases may be heat treated by the following chemical scheme.

3H ₂ + 4N + O ₂ + H2 → 2H ₂ + 2H ₂ O + 2N ₂

Except that 3H ₂ , 4N, and O ₂ are thermally decomposed gas gases,

H ₂ is hydrogens present in the second semiconductor layer.

The thermal decomposition and heat treatment may be performed simultaneously by one processing apparatus.

According to another preferred embodiment of the present invention, in a semiconductor light emitting device comprising a first semiconductor layer, an active layer and a second semiconductor layer sequentially formed on a substrate, hydrogen present in a large amount in the second semiconductor layer is ammonia and nitric acid. Removed by heat treatment.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

The semiconductor light emitting device of the present invention comprises a substrate, an N-type semiconductor layer, an active layer, and a P-type semiconductor layer sequentially formed on the substrate. Here, the hydrogen in a large amount in the P-type semiconductor layer is removed by heat treatment using ammonia and nitric acid. That is, by thermally decomposing ammonia and nitric acid into gas gases such as H ₂ , N ₂ and O _2, and then heat-treating the gas gases thus decomposed to a light emitting device manufactured in advance, thereby producing gas gases, particularly Oxygen and hydrogen present in the P-type semiconductor layer (typically composed of Mg-H conjugate) react to convert water (H ₂ O) to remove hydrogen present in the P-type semiconductor layer. Accordingly, the luminous efficiency is improved by increasing the number of holes participating in recombination with electrons doped in the N-type semiconductor.

A method of manufacturing the semiconductor light emitting device will be described in detail.

First, a semiconductor light emitting device is manufactured by sequentially forming an N-type semiconductor layer, an active layer, and a P-type semiconductor layer on a substrate prepared in advance according to a general crystal growth method.

The heat treatment process is performed using ammonia and nitric acid on the semiconductor light emitting device manufactured as described above. At this time, the present invention for the heat treatment has developed a heat treatment apparatus as shown in FIG.

2 shows a heat treatment apparatus used to manufacture a semiconductor light emitting device according to an embodiment of the present invention.

As shown in FIG. 2, the heat treatment apparatus is largely composed of a thermal decomposition unit 30 including a first reactor 32 and a heat treatment unit 50 including a second reactor 52.

The first reactor 32 of the thermal decomposition unit 30, the gas supply pipe 34 for supplying ammonia (NH3) and nitric acid (NO), and the ammonia and nitric acid supplied through the gas supply pipe 34 Heaters 38 for thermal decomposition are respectively provided. At this time, the heater 38 is made of a tungsten-based alloy is connected by a predetermined wire 36, and thermally decomposes ammonia and nitric acid, respectively, by a resistance heating method. The thermal decomposition temperature is maintained at approximately 500 ~ 1000 ℃.

As such, ammonia and nitric acid are thermally decomposed by the following chemical reaction by the thermal decomposition unit.

2NH ₃ → 3H ₂ + N ₂

2NO → 2N + O ₂

The gas gases H ₂ , N ₂ , and O ₂ thermally decomposed from the thermal decomposition unit 30 are supplied to the heat treatment unit 50. At this time, the thermal decomposition unit 30 may be supplied to the heat treatment unit 50 by injecting nitrogen (N2) through the other connecting passage 40 other than the gas supply pipe (34).

The second reactor 52 of the heat treatment part 50 is provided with a sus substrate 54 for mounting the semiconductor light emitting device 56 in which an N-type semiconductor layer, an active layer, and a P-type semiconductor layer are sequentially formed.

As described above, in the first reactor 32, ammonia and nitric acid are thermally decomposed into gas gases such as H ₂ , N ₂ , and O ₂ , respectively, and these gas gases are subjected to the heat treatment process. 2 is supplied to the reactor (52).

The heat treatment unit 50 performs a heat treatment process on the semiconductor light emitting device 56 using H ₂ , N ₂ , O ₂ gas gases in the temperature range of approximately 500 ~ 800 ℃.

Accordingly, the H ₂ , N ₂ , O ₂ gas gases react with hydrogens present in a large amount inside the P-type semiconductor layer of the semiconductor light emitting device 56, and the reaction formula is as follows.

3H ₂ + 4N + O ₂ + H ₂ → 2H ₂ + 2H ₂ O + 2N ₂

Here, 3H ₂ , 2N ₂ , and O ₂ are gas gases decomposed in the thermal decomposition unit 30, and H ₂ represents hydrogen present in the P-type semiconductor layer.

As shown in Scheme 2, when the heat treatment process is performed using gas gases (H ₂ , N ₂ , O ₂ ) thermally decomposed using ammonia and nitric acid, a large amount of hydrogen components present in the P-type semiconductor layer They participate in the heat treatment process and are converted to water (H ₂ O) to be removed.

Therefore, a large amount of hydrogen components present in the P-type semiconductor are removed, and Mg is released from the Mg-H conjugate, thereby being used as a hole for recombination with electrons. In this way, the Mg-H conjugate is formed by the hydrogens present in the P-type semiconductor in a large amount by heat treatment using H ₂ , N ₂ , O ₂ which thermally decomposes ammonia and nitric acid. By removing the hydrogen, it is possible to increase the concentration of the holes participating in the recombination to improve the luminous efficiency. In addition, it is not necessary to increase the driving voltage in order to improve the luminous efficiency.

As described above, according to the semiconductor light emitting device and the method of manufacturing the same, the inside of the P-type semiconductor layer using gas gases H ₂ , N ₂ and O ₂ thermally decomposed using ammonia and nitric acid By removing a large amount of hydrogen components, the light emission efficiency can be improved by freeing Mg from the Mg-H conjugate to increase the hole concentration.

In addition, by removing the hydrogen (H) component in the high-resistance Mg-H conjugate to decompose the Mg-H conjugate, thereby lowering the driving voltage applied for light emission can lower the power consumption effect Is expected.

Claims (10)

Sequentially forming a first semiconductor layer, an active layer, and a second semiconductor layer on the substrate; And Removing a large amount of hydrogens in the second semiconductor layer using ammonia and nitric acid Method for manufacturing a semiconductor light emitting device comprising a. The method of claim 1, Removing the hydrogens, Thermally decomposing the ammonia and the nitric acid, respectively; And Heat treating the thermally decomposed gas gases to react with hydrogen present in the second semiconductor layer Method for manufacturing a semiconductor light emitting device comprising a. The method of claim 2, wherein the thermally decomposed gas gases are formed of H ₂ , N ₂ , and O ₂ . The method of claim 2, wherein the ammonia and the nitric acid are thermally decomposed into the gas gases at a temperature in a range of 500 ° C. to 1000 ° C. 4. The method of claim 2, wherein the thermally decomposed gas gases are heat-treated at a temperature in a range of 500 ° C. to 800 ° C. to react with hydrogen present in the second semiconductor layer. The method of claim 2, wherein the gas gases are heat-treated by the following chemical reaction formula. 3H ₂ + 4N + O ₂ + H ₂ → 2H ₂ + 2H ₂ O + 2N ₂ Except that 3H ₂ , 4N, and O ₂ are thermally decomposed gas gases, H ₂ is hydrogens present in the second semiconductor layer. The method of manufacturing a semiconductor light emitting device according to claim 2, wherein the thermal decomposition and heat treatment are performed simultaneously by one processing apparatus. In a semiconductor light emitting device comprising a first semiconductor layer, an active layer and a second semiconductor layer sequentially formed on a substrate, The second semiconductor layer is a semiconductor light emitting device, characterized in that the hydrogen present in a large amount is removed by heat treatment using ammonia and nitric acid. The semiconductor light emitting device of claim 8, wherein the ammonia and the nitric acid are thermally decomposed into gas gases consisting of H ₂ , N ₂ , and O ₂ in a temperature range of 500 to 100 ° C. before heat treatment. The semiconductor light emitting device of claim 8, wherein the gas gases are heat-treated at a temperature in a range of 500 ° C. to 800 ° C. to react with hydrogen present in the second semiconductor layer.