Nitride semiconductor light emitting device and manufacturing method of the same

• US 20090159920A1
• Filed: 07/08/2008
• Published: 06/25/2009
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Hyun Soo, Sone, Cheol Soo, Kim, Yu Seung, Kang, Ki Man, Lee, Jin Hyun, Kwak, Joon Seop
• Granted Patent: US 7,928,467 B2
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

There is provided a nitride semiconductor light emitting device including: a light emitting structure including n-type and p-type nitride semiconductor layers and an active layer disposed therebetween; n- and p-electrodes electrically connected to the n-type and p-type nitride semiconductor layers, respectively; and an n-type ohmic contact layer disposed between the n-type nitride semiconductor layer and the n-electrode and including a first layer and a second layer, the first layer formed of an In-containing material, and the second layer disposed on the first layer and formed of a transparent conductive oxide. The nitride semiconductor light emitting device including the n-electrode exhibits high light transmittance and superior electrical characteristics. Further, the nitride semiconductor light emitting device can be manufactured by an optimal method to ensure superb optical and electrical characteristics.

Claims

1. A nitride semiconductor light emitting device comprising:

a light emitting structure comprising n-type and p-type nitride semiconductor layers and an active layer disposed therebetween;

n- and p-electrodes electrically connected to the n-type and p-type nitride semiconductor layers, respectively; and

an n-type ohmic contact layer disposed between the n-type nitride semiconductor layer and the n-electrode and comprising a first layer and a second layer, the first layer formed of an In-containing material, and the second layer disposed on the first layer and formed of a transparent conductive oxide.

2. The nitride semiconductor light emitting device of claim 1, wherein the first layer is formed of an In alloy.

3. The nitride semiconductor light emitting device of claim 2, wherein the In alloy comprises at least one element selected from a group consisting of Ti, Al, Cr, Ni, Pd, Pt, Mo, Co and Mg.

4. The nitride semiconductor light emitting device of claim 1, wherein the second layer comprises at least one material selected from a group consisting of In, Sn, Al, Zn and Ga.

5. The nitride semiconductor light emitting device of claim 1, wherein the second layer comprises at least one material selected from a group consisting of ITO, CIO, AZO, ZnO, NiO and In₂O₃.

6. The nitride semiconductor light emitting device of claim 1, wherein the first layer has a thickness ranging from 10 to 300 Å

.

7. The nitride semiconductor light emitting device of claim 1, wherein the second layer has a thickness ranging from 500 to 5000 Å

.

8. The nitride semiconductor light emitting device of claim 1, wherein a surface of the n-type nitride semiconductor layer where the n-type ohmic contact layer is formed is one of a Ga-polar surface and an N-polar surface.

9. A method of manufacturing a nitride light emitting device, the method comprising:

depositing an n-type nitride semiconductor layer, an active layer and a p-type nitride semiconductor layer sequentially to form a light emitting structure;

forming an n-type ohmic contact layer by forming a first layer made of an In-containing material on one surface of the n-type nitride semiconductor layer and a second layer made of a transparent conductive oxide on the first layer;

forming an n-electrode on the n-type ohmic contact layer; and

forming a p-electrode to electrically connect to the p-type nitride semiconductor layer.

10. The method of claim 9, further comprising heat-treating the n-type ohmic contact layer, after the forming an n-type ohmic contact layer.

11. The method of claim 10, wherein the heat-treating the n-type ohmic contact layer is performed at a temperature of 300 to 500°

C.

12. The method of claim 9, wherein the first layer is formed by sputtering.