KR100899917B1 - Light emitting device using nitride compound semiconductor and method of manufacturing the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device using a nitride compound semiconductor, and a method of manufacturing the same. Sequentially stacking an active layer and a P-compound semiconductor layer; Mesa etching from the P-compound semiconductor layer to a part of the first N-compound semiconductor layer; Forming a P-electrode on the P-compound semiconductor layer and forming an N-electrode on the mesa-etched first N-compound semiconductor layer to manufacture a device.

Therefore, the present invention does not increase the doping concentration of the entire N-compound semiconductor layer, but increases the doping concentration of the N-type carrier to a portion of the N-compound semiconductor layer, and the layer doped with a high concentration N-type carrier is a channel of electrical conduction. By using this, the effect of suppressing defect generation and lowering the electrical resistance is generated.

Nitride, Semiconductor, High Concentration, N Type, Carrier

Description

Light emitting device using nitride compound semiconductor and method of manufacturing the same

1 is a cross-sectional view of a light emitting device using a general nitride compound semiconductor.

2 is a schematic diagram showing electron flow and non-uniform emission state of a light emitting device using a general nitride-based compound semiconductor.

3A to 3C are cross-sectional views illustrating manufacturing steps of a light emitting device using a nitride compound semiconductor according to the present invention.

4 is a schematic diagram showing electron flow and a uniform light emitting state of a light emitting device using a nitride compound semiconductor according to the present invention.

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

100,200: substrate 101,201,222a, 222b, 222c: N-compound semiconductor layer

111,230 active layer 102,240 P-compound semiconductor layer

105: transparent electrode 107,252: P-electrode

108,251: N-electrode

221,221a, 221b, 221c: compound semiconductor layer doped with high concentration N-type carrier

The present invention relates to a light emitting device using a nitride compound semiconductor and a method of manufacturing the same. More specifically, a portion of the N-compound semiconductor layer increases a doping concentration of an N-type carrier and a layer doped with a high-concentration N-type carrier. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device using a nitride compound semiconductor capable of suppressing defect generation and lowering electrical resistance by using as a channel for electrical conduction, and a method of manufacturing the same.

In recent years, the light emitting device using the nitride compound semiconductor has been gradually expanded to various fields.

In particular, LD and LED using these materials can be said to be essential for the development of a full color display board, a display such as a traffic light, and a high density optical recording medium.

The light emitting device using such a nitride compound semiconductor has been extended to the general illumination area.

As such, in order to cope with an application requiring high brightness, a large area high output device is required, unlike a low brightness device such as an indicator lamp.

It is known that a large portion of the electrical resistance in the low output device is caused by P-GaN, whereas the large portion of the electrical resistance due to N-GaN is known to be larger in the large output device.

Therefore, increasing the electrical conductivity of N-GaN, which has not been a problem so far, has emerged as an important element for implementing stable device characteristics.

N-GaN is obtained through silicon doping, and increasing silicon doping concentration is the most common way to reduce resistance.

However, when the silicon doping concentration increases to 5 X 10 ¹⁸ / cm 3 or more, structural defects such as cracking in N-GaN may occur due to an increase in strain due to silicon doping.

Therefore, there is a limit to lowering the resistance of N-GaN only by silicon doping.

In order to form N-GaN with lower resistance at limited silicon doping concentration, other structural changes are required, and if the electrical conductivity of N-GaN can be lowered through this, it can contribute to the improvement of characteristics and lifetime of nitride-based light emitting devices. There will be.

1 is a cross-sectional view of a light emitting device using a general nitride-based compound semiconductor, an N-compound semiconductor layer 101 formed on an upper portion of a substrate 100 and etched a portion of the upper portion thereof; An active layer 111 formed on an unetched top of the N-compound semiconductor layer 101; A P-compound semiconductor layer 102 formed on the active layer 111; A current spreading transparent electrode 105 formed on the P-compound semiconductor layer 102; A P-electrode 107 formed on the current spreading transparent electrode 105; The N-electrode 108 is formed on the etched top of the N-compound semiconductor layer.

When holes and electrons are injected into the P-electrode 107 and the N-electrode 108, holes and electrons are recombined in the active layer 111 to emit light.                         

FIG. 2 is a schematic diagram illustrating electron flow and non-uniform emission state of a light emitting device using a general nitride-based compound semiconductor. In the general light emitting device, carrier movement is performed along an electron transfer pass close to the N-electrode 108. In this case, light emission is concentrated in the region.

Therefore, in the conventional light emitting device, light is concentrated in a region where electrons are easy to move, that is, light emission intensity is not uniform in the entire region, and heat is excessively generated in the local region, thereby improving reliability of the device. It caused the problem of deterioration.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and increases the doping concentration of the N-type carrier to a part of the N-compound semiconductor layer without increasing the doping concentration of the entire N-compound semiconductor layer, and the high concentration N. It is an object of the present invention to provide a light emitting device using a nitride compound semiconductor capable of suppressing defect generation and lowering electrical resistance by using a layer doped with a type carrier as a channel for electrical conduction, and a method of manufacturing the same.

A preferred aspect for achieving the above object of the present invention comprises: a first N-compound semiconductor layer formed on an upper portion of a substrate, the upper portion of which is partially removed;

A compound semiconductor layer doped with a high concentration N-type carrier formed on the first N-compound semiconductor layer;

A second N-compound semiconductor layer formed on the compound semiconductor layer doped with the high concentration N-type carrier;                         

An active layer formed on the second N-compound semiconductor layer;

A P-compound semiconductor layer formed over the active layer;

A light emitting device using a nitride compound semiconductor composed of an electrode formed on the upper portion of the P-compound semiconductor layer and the removed upper portion of the first N-compound semiconductor layer is provided.

Another preferred aspect for achieving the above object of the present invention is a compound semiconductor layer doped with a first N-compound semiconductor layer, a high concentration N-type carrier, a second N-compound semiconductor layer, Sequentially stacking an active layer and a P-compound semiconductor layer;

Mesa etching from the P-compound semiconductor layer to a part of the first N-compound semiconductor layer;

A method of manufacturing a light emitting device using a nitride compound semiconductor comprising forming a P-electrode on the P-compound semiconductor layer and forming an N-electrode on the mesa-etched first N-compound semiconductor layer. Is provided.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3A to 3C are cross-sectional views illustrating a manufacturing process of a light emitting device using a nitride compound semiconductor according to the present invention. First, a first N-compound semiconductor layer 201 and a high concentration N-type carrier are doped on a substrate 200. The compound semiconductor layer 221, the second N-compound semiconductor layer 222, the active layer 230, and the P-compound semiconductor layer 24O are sequentially stacked (FIG. 3A).

Here, a plurality of stacked epitaxial layers including the compound semiconductor layer 221 and the second N-compound semiconductor layer 222 doped with the high concentration N-type carrier may be formed.

The compound semiconductor layer 221 doped with the high concentration N-type carrier is preferably formed by growing a compound semiconductor layer while injecting silicon (Si).

In addition, the compound semiconductor layer is preferably GaN.

Thereafter, Mesa is etched from the P-compound semiconductor layer 240 to a part of the second N-compound semiconductor layer 222 (FIG. 3B).

Finally, a P-electrode 252 is formed on the P-compound semiconductor layer 240, and an N-electrode 251 is formed on the mesa-etched N-compound semiconductor layer 222. (FIG. 3C)

FIG. 4 is a schematic diagram showing electron flow and uniform emission state of a light emitting device using a nitride compound semiconductor according to the present invention. The present invention provides a low luminance N-compound semiconductor layer required for a high luminance large area blue / green light emitting device. In order to realize the electrical resistance, a channel layer having a different silicon doping concentration (ie, a compound semiconductor layer 221 doped with a high concentration N-type carrier shown in FIG. 3A) is inserted into the N-compound semiconductor layer.

Referring to FIG. 4, the compound semiconductor layers 221a, 221b and 221c doped with a high concentration N-type carrier and the second N-compound semiconductor layers 222a, 222b and 222c are disposed on the first N-compound semiconductor layer 201. Stacked epitaxial layers 220a, 220b, and 220c are laminated.

In this case, the compound semiconductor layers 221a, 221b, and 221c doped with a high concentration N-type carrier, which are channel layers having different silicon doping concentrations, may be formed of the first N-compound semiconductor layer 201 and the second N-compound semiconductor layer 222a. (222b, 222c) It is a layer that lowers the electrical resistance by injecting more silicon, and has a very thin thickness of 10-20 nm in order to suppress defects such as cracks in the N-compound semiconductor layer due to strain increase due to silicon doping. It is configured to have.

Therefore, the compound semiconductor layer doped with a high concentration N-type carrier is used as a channel of electrical conduction, and thus, the present invention suppresses defect generation caused by doping the high concentration N-type carrier and at the same time, lowers electrical resistance.

Therefore, the present invention can reduce the difference in luminous intensity of the entire region by using a low resistance channel layer capable of supplying electrons evenly, and uniformly radiates the entire region to reduce heat generation, thereby preventing a decrease in reliability. There is an advantage.

As described above, the present invention increases the doping concentration of the N-type carrier to only a part of the N-compound semiconductor layer and suppresses defect generation by using a layer doped with a high-concentration N-type carrier as a channel for electric conduction. At the same time, there is an effect of lowering the electrical resistance.

In addition, it is possible to suppress the phenomenon in which the light emission is concentrated only in a part of the light emitting device and evenly induce light emission, thereby preventing the degradation of reliability caused by efficient light emission and local heat generation due to local light emission.                     

Through this, it is possible to secure the electrical conductivity required for manufacturing a high-brightness large area light emitting device without generating defects, and also to reduce the operating voltage of the device.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (6)

A first N-compound semiconductor layer formed over the substrate and partially removed from the substrate; A compound semiconductor layer doped with a high concentration N-type carrier formed on the first N-compound semiconductor layer; A second N-compound semiconductor layer formed on the compound semiconductor layer doped with the high concentration N-type carrier; An active layer formed on the second N-compound semiconductor layer; A P-compound semiconductor layer formed over the active layer; A light emitting device using a nitride compound semiconductor consisting of electrodes formed on top of the P-compound semiconductor layer and on top of the first N-compound semiconductor layer. Sequentially stacking a first N-compound semiconductor layer, a compound semiconductor layer doped with a high concentration N-type carrier, a second N-compound semiconductor layer, an active layer and a P-compound semiconductor layer on the substrate; Mesa etching from the P-compound semiconductor layer to a part of the first N-compound semiconductor layer; Forming a P-electrode on the P-compound semiconductor layer and forming an N-electrode on the mesa-etched first N-compound semiconductor layer. The method of claim 2, The nitride-based compound semiconductor is characterized in that a plurality of stacked epitaxial layer formed of the compound semiconductor layer doped with the high concentration N-type carrier and the second N-compound semiconductor layer between the first N-compound semiconductor layer and the active layer Light emitting device manufacturing method using. The method of claim 2, The compound semiconductor layer doped with the high concentration N-type carrier, A method of manufacturing a light emitting device using a nitride compound semiconductor, wherein the compound semiconductor layer is grown by implanting silicon (Si). The method according to claim 2 or 4, The compound semiconductor layer doped with the high concentration N-type carrier is a light emitting device manufacturing method using a nitride-based compound semiconductor, characterized in that formed to a thickness of 10 ~ 20nm. The method of claim 2, The compound semiconductor layer doped with the high concentration N-type carrier is GaN manufacturing method of a light emitting device using a nitride compound semiconductor.

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