III-nitride compound semiconductor light emitting device

• US 7,622,742 B2
• Filed: 07/02/2004
• Issued: 11/24/2009
• Est. Priority Date: 07/03/2003
• Status: Expired due to Fees

• Current Assignee: Epivalley Co., Ltd.
• Original Assignee: Epivalley Co., Ltd.
• Inventors: Kim, Jong-Won, Jang, Pil-Guk, Kim, Keuk, Jeon, Soo-Kun, Kim, Chang-Tae
• Primary Examiner(s): Weiss; Howard
• Assistant Examiner(s): RAO, SHRINIVAS H
• Application Number:
  US10/562,738
• Publication Number:
  US 20070114511A1
• Time in Patent Office: 1,971 Days
• Field of Search: 257/79, 257/98, 257/E29.01, 372/46, 438/700
• US Class Current: 257/79
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

The present invention relates to a III-nitride semiconductor light-emitting device having high external quantum efficiency, provides a III-nitride compound semiconductor light-emitting device including an active layer generating light by recombination of electrons and holes and containing gallium and nitrogen, an n-type Al(x)ln(y)Ga(1-x-y)N layer epitaxially grown before the active layer is grown, and an n-type electrode electrically contacting with the n-type Al(x)ln(y)Ga(1-x-y)N layer, in which the n-type Al(x)ln(y)Ga(1-x-y)N layer has a surface which is exposed by etching and includes a region for scribing and breaking the device and a region for contact with the n-type electrode, and the surface of the region for scribing and breaking the device is roughened, thereby it is possible to increase external quantum efficiency of the light-emitting device.

Claims

1. A III-nitride compound semiconductor light-emitting device comprising:

a plurality of III-nitride compound semiconductor layers that are epitaxially grown using a substrate, the plurality of III-nitride compound semiconductor layers including;

an active layer generating light by recombination of electrons and holes and containing gallium and nitrogen,

an n-type Al(x)ln(y)Ga(1-x-y)N layer epitaxially grown before the active layer is grown, and

an n-type electrode electrically contacting with the n-type Al(x)ln(y)Ga(1-x-y)N layer, and

wherein the n-type Al(x)ln(y)Ga(1-x-y)N layer has a top surface which is exposed by etching, the exposed top surface includes a region for scribing and breaking the device and a region for contact with the n-type electrode, and a top surface of the region for scribing and breaking the device including a roughened surface such that light generated from the active layer escapes outwardly from the device through said roughened surface.

2. The III-nitride compound semiconductor light-emitting device of claim 1, wherein the roughened top surface of the region for scribing and breaking the device is formed by dry etching.

3. The III-nitride compound semiconductor light-emitting device of claim 2, wherein a mask pattern is used in the dry etching.

4. The III-nitride compound semiconductor light-emitting device of claim 3, wherein surface gratings are formed by means of the mask pattern, the surface area of each of the surface gratings is in a range of 1.5 μ

m² to 4 μ

m².

5. The III-nitride compound semiconductor light-emitting device of claim 3, wherein surface gratings are formed by means of the mask pattern, the height of each of the surface gratings is in a range of 0.5 μ

m to 1.5 μ

m.

6. The III-nitride compound semiconductor light-emitting device of claim 3, wherein etching residues are used as the mask pattern in the dry etching.

7. The III-nitride compound semiconductor light-emitting device of claim 6, wherein protrusions are formed by mean of the mask pattern and each of the protrusions has a conical shape.

8. The III-nitride compound semiconductor light-emitting device of claim 7, wherein the diameter of the bottom of the conical shape is in the range of 1 nm to 10 μ

m.

9. The III-nitride compound semiconductor light-emitting device of claim 7, wherein the height of the conical shape is in the range of 1 nm to 10 μ

m.

10. The III-nitride compound semiconductor light-emitting device of claim 1, wherein the roughened top surface of the region for scribing and breaking the device is formed by wet etching.

11. The III-nitride compound semiconductor light-emitting device of claim 10, wherein the wet etching is a photoelectrochemical etching.

12. The III-nitride compound semiconductor light-emitting device of claim 11, wherein KOH solution is used as an etching solution in the photoelectrochemical etching.

13. The III-nitride compound semiconductor light-emitting device of claim 3, wherein the dry etching is performed after the region for contact with the n-type electrode is etched.