Nitride semiconductor light emitting device

• US 7,612,362 B2
• Filed: 11/16/2007
• Issued: 11/03/2009
• Est. Priority Date: 11/22/2006
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Komada, Satoshi
• Primary Examiner(s): Pert, Evan
• Assistant Examiner(s): Wilson, Scott R
• Application Number:
  US11/941,453
• Publication Number:
  US 20080116477A1
• Time in Patent Office: 718 Days
• Field of Search: 257/13, 257/76, 257/78, 257 79-103, 257/918, 257/E29.315
• US Class Current: 257/13
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• 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 33/32 containing nitrogen

Abstract

A nitride semiconductor light emitting device includes a substrate, and a first n-type nitride semiconductor layer, a light emitting layer, a first p-type nitride semiconductor layer, a second p-type nitride semiconductor layer, a p-type nitride semiconductor tunnel junction layer, an n-type nitride semiconductor tunnel junction layer and a second n-type nitride semiconductor layer that are formed on the substrate. The p-type nitride semiconductor tunnel junction layer and the n-type nitride semiconductor tunnel junction layer form a tunnel junction, and the p-type nitride semiconductor tunnel junction layer has an indium content ratio higher than that of the second p-type nitride semiconductor layer. At least one of the p-type nitride semiconductor tunnel junction layer and the n-type nitride semiconductor tunnel junction layer includes aluminum.

Claims

1. A nitride semiconductor light emitting device comprising:

a substrate;

a first n-type nitride semiconductor layer formed on said substrate;

a light emitting layer formed on said first n-type nitride semiconductor layer;

a first p-type nitride semiconductor layer formed on said light emitting layer;

a second p-type nitride semiconductor layer formed on said first p-type nitride semiconductor layer;

a p-type nitride semiconductor tunnel junction layer formed on said second p-type nitride semiconductor layer, the p-type nitride semiconductor tunnel junction layer comprising p-type nitride semiconductor material including indium;

an n-type nitride semiconductor tunnel junction layer formed on said p-type nitride semiconductor tunnel junction layer;

a second n-type nitride semiconductor layer formed on said n-type nitride semiconductor tunnel junction layer, the second p-type nitride semiconductor layer comprising p-type nitride semiconductor material including indium; and

wherein said p-type nitride semiconductor tunnel junction layer and said n-type nitride semiconductor tunnel junction layer form a tunnel junction, and said p-type nitride semiconductor tunnel junction layer has an indium content ratio higher than an indium content ratio of said second p-type nitride semiconductor layer.

2. The nitride semiconductor light emitting device according to claim 1, wherein

said second p-type nitride semiconductor layer has a thickness of not less than 2 nm.

3. The nitride semiconductor light emitting device according to claim 1, wherein

said second p-type nitride semiconductor layer has its thickness of not less than a critical thickness.

4. The nitride semiconductor light emitting device according to claim 1, wherein

said second p-type nitride semiconductor layer is doped with a p-type impurity with a doping density of not less than 1×

10¹⁹/cm³.

5. The nitride semiconductor light emitting device according to claim 1, wherein

said p-type nitride semiconductor tunnel junction layer has a thickness of not more than 5 nm.

6. The nitride semiconductor light emitting device according to claim 1, wherein

said p-type nitride semiconductor tunnel junction layer is doped with a p-type impurity with a doping density of not less than 1×

10¹⁹/cm³.

7. The nitride semiconductor light emitting device according to claim 1, wherein

said first p-type nitride semiconductor layer has its band gap larger than that of said second p-type nitride semiconductor layer, and said second p-type nitride semiconductor layer has its band gap larger than that of said p-type nitride semiconductor tunnel junction layer.

8. The nitride semiconductor light emitting device according to claim 1, wherein

said n-type nitride semiconductor tunnel junction layer includes indium.

9. The nitride semiconductor light emitting device according to claim 1, wherein

said n-type nitride semiconductor tunnel junction layer is doped with an n-type impurity with a doping density of not less than 1×

10¹⁹/cm³.

10. The nitride semiconductor light emitting device according to claim 1, wherein

said n-type nitride semiconductor tunnel junction layer has a thickness of not more than 10 nm.

11. A nitride semiconductor light emitting device comprising:

a substrate;

a first n-type nitride semiconductor layer formed on said substrate;

a light emitting layer formed on said first n-type nitride semiconductor layer;

a p-type nitride semiconductor layer formed on said light emitting layer;

a p-type nitride semiconductor tunnel junction layer formed on said p-type nitride semiconductor layer;

an n-type nitride semiconductor tunnel junction layer formed on said p-type nitride semiconductor tunnel junction layer; and

a second n-type nitride semiconductor layer formed on said n-type nitride semiconductor tunnel junction layer;

wherein said p-type nitride semiconductor tunnel junction layer and said n-type nitride semiconductor tunnel junction layer form a tunnel junction, and at least one of said p-type nitride semiconductor tunnel junction layer and said n-type nitride semiconductor tunnel junction layer includes aluminum;

an aluminum content of at least one of said p-type nitride semiconductor tunnel junction layer and said n-type nitride semiconductor tunnel junction layer is not less than 1 atomic % and not more than 5 atomic %; and

said p-type nitride semiconductor tunnel junction layer includes aluminum and indium, and indium content is higher than aluminum content.

12. The nitride semiconductor light emitting device according to claim 11, wherein

said p-type nitride semiconductor tunnel junction layer is doped with a p-type impurity with a doping density of not less than 1×

10¹⁹/cm³.

13. The nitride semiconductor light emitting device according to claim 11, wherein

said n-type nitride semiconductor tunnel junction layer is doped with an n-type impurity with a doping density of not less than 1×

10¹⁹/cm³.

14. The nitride semiconductor light emitting device according to claim 11, wherein

said n-type nitride semiconductor tunnel junction layer has a thickness of not more than 10 nm.

15. A nitride semiconductor light emitting device comprising:

a substrate;

a first n-type nitride semiconductor layer formed on said substrate;

a light emitting layer formed on said first n-type nitride semiconductor layer;

a p-type nitride semiconductor layer formed on said light emitting layer;

a p-type nitride semiconductor tunnel junction layer formed on said p-type nitride semiconductor layer;

an n-type nitride semiconductor tunnel junction layer formed on said p-type nitride semiconductor tunnel junction layer; and

a second n-type nitride semiconductor layer formed on said n-type nitride semiconductor tunnel junction layer;

wherein said p-type nitride semiconductor tunnel junction layer and said n-type nitride semiconductor tunnel junction layer form a tunnel junction;

at least one of said p-type nitride semiconductor tunnel junction layer and said n-type nitride semiconductor tunnel junction layer includes aluminum;

an aluminum content of at least one of said p-type nitride semiconductor tunnel junction layer and said n-type nitride semiconductor tunnel junction layer is not less than 1 atomic % and not more than 5 atomic %; and

said n-type nitride semiconductor tunnel junction layer includes aluminum and indium, and indium content is higher than aluminum content.

16. The nitride semiconductor light emitting device according to claim 15, wherein

said p-type nitride semiconductor tunnel junction layer is doped with a p-type impurity with a doping density of not less than 1×

10¹⁹/cm³.

17. The nitride semiconductor light emitting device according to claim 15, wherein

said n-type nitride semiconductor tunnel junction layer is doped with an n-type impurity with a doping density of not less than 1×

10¹⁹/cm³.

18. The nitride semiconductor light emitting device according to claim 15, wherein

said n-type nitride semiconductor tunnel junction layer has a thickness of not more than 10 nm.