Flip chip type nitride semiconductor light emitting device and manufacturing method thereof

• US 20050145875A1
• Filed: 06/07/2004
• Published: 07/07/2005
• Est. Priority Date: 12/24/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kim, Hyun Kyung, Shin, Hyoun Soo, Kim, Yong Chun
• Granted Patent: US 7,235,818 B2
• Time in Patent Office: Days
• US Class Current: 257/103
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials

Abstract

Disclosed herein are a flip chip type nitride semiconductor light emitting device, which comprises a substrate for growing a nitride semiconductor material, an n-type nitride semiconductor layer formed on the substrate, an active layer formed on at least a part of the n-type nitride semiconductor layer, a p-type nitride semiconductor layer formed on the active layer, a bonding force providing layer formed on the p-type nitride semiconductor layer and adapted to provide a bonding force relative to the p-type nitride semiconductor layer, a reflective electrode layer formed on the bonding force providing layer, and adapted to reflect light produced in the active layer toward the substrate and to diffuse electric current, and a cap layer formed on the reflective electrode layer, and adapted to provide a bonding force between the reflective electrode layer and a bonding metal and to reduce contact resistance.

Claims

1. A flip chip type nitride semiconductor light emitting device comprising:

a substrate for growing a nitride semiconductor material;

an n-type nitride semiconductor layer formed on the substrate;

an active layer formed on at least a part of the n-type nitride semiconductor layer;

a p-type nitride semiconductor layer formed on the active layer;

a bonding force providing layer formed on the p-type nitride semiconductor layer and adapted to provide a bonding force relative to the p-type nitride semiconductor layer;

a reflective electrode layer formed on the bonding force providing layer, and adapted to reflect light produced in the active layer toward the substrate and to diffuse electric current; and

a cap layer formed on the reflective electrode layer, and adapted to provide a bonding force between the reflective electrode layer and a bonding metal and to reduce contact resistance.

2. The device as set forth in claim 1, wherein the bonding force providing layer is made of one metal or alloys of two or more metals selected from among the group consisting of Ni, Co, Pd, Ir, Rh, Ru, Zn, Mg, and Sn.

3. The device as set forth in claim 1, wherein the bonding force providing layer has a thickness of 5 Å

to 50 Å

.

4. The device as set forth in claim 1, wherein the reflective electrode layer is made of one metal or alloys of two or more metals selected from among the group consisting of Ag, Rh and Al.

5. The device as set forth in claim 1, wherein the reflective electrode layer has a thickness of 500 Å

to 5000 Å

.

6. The device as set forth in claim 1, wherein the cap layer is made of one metal selected from among the group consisting of Pt, Pd and Ph.

7. The device as set forth in claim 1, wherein the cap layer has a thickness of 100 Å

or more while being smaller than that of the reflective electrode layer.

8. A method of manufacturing a flip chip type nitride semiconductor light emitting device comprising the steps of:

a) preparing a substrate for growing a nitride semiconductor material;

b) successively forming, on the substrate, an n-type nitride semiconductor layer, an active layer, and a p-type nitride semiconductor layer;

c) removing at least a part of the p-type nitride semiconductor layer and at least a part of the active layer so as to expose a partial region of the n-type nitride semiconductor layer;

d) forming a bonding force providing layer on the p-type nitride semiconductor layer so as to provide a bonding force relative to the p-type nitride semiconductor layer;

e) forming a reflective electrode layer on the bonding force providing layer so as to reflect light produced in the active layer toward the substrate, and to achieve diffusion of electric current; and

f) forming a cap layer on the reflective electrode layer so as to provide a bonding force between the reflective electrode layer and a bonding metal, and to reduce contact resistance.

9. The method as set forth in claim 8, after the step f), further comprising the steps of:

g) performing a heat treatment process; and

h) forming an n-side electrode on the exposed partial region of the n-type nitride semiconductor layer, and a p-side bonding electrode on the cap layer.

10. The method as set forth in claim 9, wherein in the step g) the heat treatment process is a rapid heat treatment process performed at a temperature of 400°

C. to 600°

C. for 1 minute to 5 minutes under nitrogen atmosphere.

11. The method as set forth in claim 8, wherein the step d) is performed by depositing one metal or alloys of two or more metals selected from among the group consisting of Ni, Co, Pd, Ir, Rh, Ru, Zn, Mg, and Sn on the p-type nitride semiconductor layer in a thickness of 5 Å

to 50 Å

.

12. The method as set forth in claim 8, wherein the step e) is performed by depositing one metal or alloys of two or more metals selected from among the group consisting of Ag, Rh and Al on the bonding force providing layer in a thickness of 500 Å

to 5000 Å

.

13. The method as set forth in claim 8, wherein the step f) is performed by depositing one metal selected from among the group consisting of Pt, Pd and Ph in a thickness of 100 Å

or more while being smaller than that of the reflective electrode layer.