Nitride Semiconductor Light Emitting Device and Fabrication Method Thereof

• US 20100289002A1
• Filed: 08/03/2010
• Published: 11/18/2010
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: Suk Hun Lee
• Inventors: Lee, Suk Hun
• Granted Patent: US 8,278,646 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/305 characterised by the doping materials
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

Provided is a nitride semiconductor light emitting device including: a first nitride semiconductor layer; an active layer formed above the first nitride semiconductor layer; and a delta doped second nitride semiconductor layer formed above the active layer. According to the present invention, the optical power of the nitride semiconductor light emitting device is enhanced, optical power down phenomenon is improved and reliability against ESD (electro static discharge) is enhanced.

Claims

1. A light emitting device comprising:

a first GaN based semiconductor layer;

a delta doped second GaN based semiconductor layer; and

an active layer between the first GaN based semiconductor layer and the delta doped second GaN based semiconductor layer;

wherein the delta doped second GaN based semiconductor layer includes a delta doped GaN based semiconductor layer and an un-doped GaN based semiconductor layer between the delta doped GaN based semiconductor layer and the active layer.

2. The light emitting device according to claim 1, further comprising a third GaN based semiconductor layer on the delta doped second GaN based semiconductor layer.

3. The light emitting device according to claim 2, wherein the third GaN based semiconductor layer is formed of an n-InGaN layer with an SG (super grading) structure in which indium content is gradually varied, or of an n-InGaN/InGaN super lattice structure layer.

4. The light emitting device according to claim 2, further comprising a Si-doped GaN layer between the third GaN based semiconductor layer and the delta doped second GaN based semiconductor layer.

5. The light emitting device according to claim 2, further comprising a transparent electrode on the third GaN based semiconductor layer.

6. The light emitting device according to claim 1, further comprising:

a buffer layer under the first GaN based semiconductor layer; and

a substrate under the buffer layer.

7. The light emitting device according to claim 1, further comprising a low mole indium-containing nitride layer between the first GaN based semiconductor layer and the active layer, wherein the low mole indium-containing nitride layer has an indium content of 1-5%.

8. The light emitting device according to claim 1, wherein the delta doped second GaN based semiconductor layer is grown in a thickness range of 10-300 Å

.

9. The light emitting device according to claim 1, wherein the delta doped second GaN based semiconductor layer includes at least one repeatedly grown structure selected from the group consisting of undoped GaN/delta doped p-GaN, undoped AlGaN/delta doped p-GaN, undoped InGaN/delta doped p-GaN, undoped GaN/undoped AlGaN cap/delta doped p-GaN, and undoped InGaN/undoped AlGaN cap/delta doped p-GaN structures.

10. The light emitting device according to claim 1, wherein the delta doped second GaN based semiconductor layer is formed with at least one period consisting of layers where the doping dose is changed, wherein the period is repeatedly grown in the delta doped second GaN based semiconductor layer.

11. The light emitting device according to claim 1, wherein the delta doped second GaN based semiconductor layer comprises at least one selected from the group consisting of Mg delta doped GaN layer, Mg—

Al delta doped GaN layer and Mg—

Al—

In delta doped GaN layer.

12. The light emitting device according to claim 1, wherein the delta doped second GaN based semiconductor layer is grown repeatedly at least two times where one period is one selected from the group consisting of undoped GaN layer/delta doped p-GaN layer, undoped AlGaN layer/delta doped p-GaN layer, undoped InGaN layer/delta doped p-GaN layer, undoped GaN layer/undoped AlGaN cap layer/delta doped p-GaN layer, and undoped InGaN layer/undoped AlGaN cap layer/delta doped p-GaN layer structures such that the selected layers constituting the one period have different thicknesses.

13. The light emitting device according to claim 1, wherein the first GaN based semiconductor layer is an n-GaN layer formed by a Si—

In simultaneous doping in a doping concentration range of 1×

10¹⁹/cm³-9×

10¹⁹/cm³ at a thickness range of 1-4 μ

m.

14. The light emitting device according to claim 1, wherein the first GaN based semiconductor layer is formed in an overall thickness less than 2 μ

m by growing repeatedly at least two times an undoped-AlGaN/doped-GaN super lattice structure.

15. The light emitting device according to claim 1, wherein the first GaN based semiconductor layer includes n-type impurities and the delta doped second GaN based semiconductor layer includes p-type impurities.

16. A light emitting device comprising:

a first GaN based semiconductor layer;

an active layer on the first GaN based semiconductor layer in a single quantum well structure or a multi quantum well structure comprising a well layer and a barrier layer; and

an Mg-delta doped second GaN based semiconductor layer on the active layer.

17. The light emitting device according to claim 16, wherein the Mg-delta doped second GaN based semiconductor layer is a second electrode contact layer.

18. The light emitting device according to claim 16, further comprising an n-type second electrode contact layer on the Mg-delta doped second GaN based semiconductor layer.

19. The light emitting device according to claim 16, wherein the active layer further comprises an SiNx cluster layer interposed between the well layer and the barrier layer.

20. A light emitting device comprising:

a first GaN based semiconductor layer;

an active layer formed above the first GaN based semiconductor layer; and

a delta doped second GaN based semiconductor layer formed above the active layer,

wherein the delta doped second GaN based semiconductor layer is formed with at least one period consisting of layers where the doping dose is changed, wherein the period is repeatedly grown in the delta doped second GaN based semiconductor layer.