Nitride Semiconductor Light Emitting Element and Method for Manufacturing the Same

• US 20080135868A1
• Filed: 09/29/2005
• Published: 06/12/2008
• Est. Priority Date: 10/01/2004
• Status: Abandoned Application

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Cable Industries Limited (Mitsubishi Materials Corporation)
• Inventors: Hiraoka, Shin, Okagawa, Hiroaki
• Application Number:
  US11/664,386
• Publication Number:
  US 20080135868A1
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/405 Reflective materials

Abstract

In an element structure of a nitride semiconductor light emitting element, the laminate including a light emitting part having a laminate structure of a first n-type layer 13, a p-type clad layer 15 and an active layer 14 sandwiched between them, and a second n-type layer 16 present at the outer side of the light emitting part and at the p-type clad layer side. When the laminate is to be grown on a substrate 11, the light emitting part has the p-type clad layer 15 placed on the upper side of the second n-type layer 16 is placed on the further upper side of the light emitting part. The second n-type layer 16 is dry-etched to form an exposed surface. An electrode P12 is formed on the surface exposed by dry etching, whereby the electrode P12 becomes a p-side electrode having a low contact resistance, which is used for injecting a hole in the p-type clad layer 15 of the aforementioned light emitting part, even if the electrode P12 is formed in the n-type layer 16.

Claims

1. A nitride semiconductor light emitting element comprising a laminate made of nitride semiconductor layers, the laminate including:

one light emitting part having a laminate structure of a first n-type layer, a p-type layer and an active layer sandwiched between them, and

a second n-type layer present at the outer side of the light emitting part and at the p-type layer side, wherein

the second n-type layer has a surface exposed by dry etching, and a p-side electrode for injecting a hole into the p-type layer of said light emitting part is formed on the exposed surface, the p-side electrode being formed by using a material selected from the group consisting of Al, Ti, W, Cr and ITO, and

wherein the laminate is formed by sequentially growing nitride semiconductor layers on the substrate,

when the substrate is on the lower side, the light emitting part is included in the laminate in such a manner that the first n-type layer is on the lower side and the p-type layer is on the upper side, and

the second n-type layer is located at the upper side of the light emitting part.

6. The nitride semiconductor light emitting element of claim 1, wherein the entire upper surface of the second n-type layer is dry etched, and the p-side electrode is formed on the dry etched surface.

7. The nitride semiconductor light emitting element of claim 6, wherein the p-side electrode is formed on approximately the entire surface of the above-mentioned dry etched surface.

9. The nitride semiconductor light emitting element of claim 1, wherein the dry etched side of the surface of the second n-type layer is a concavo-convex surface formed by the dry etching.

10. The nitride semiconductor light emitting element of claim 9, wherein the surface of the dry etched side of the second n-type layer has a nitride semiconductor layer layered on said surface prior to the dry etching, the dry etching is applied to the second n-type layer from the surface of the layered nitride semiconductor layer to reach the second n-type layer.

11. The nitride semiconductor light emitting element of claim 9, wherein the p-side electrode is formed on approximately the entire surface of the concavo-convex surface.

13. The nitride semiconductor light emitting element of claim 9, wherein the p-side electrode is formed only in the concave part of the concavo-convex surface, and the p-side electrode is absent in the upper part of the convex part.

16. The nitride semiconductor light emitting element of claim 10, herein the p-side electrode is formed on approximately the entire surface of the concavo-convex surface.

18. The nitride semiconductor light emitting element of claim 10, wherein the p-side electrode is formed only in the concave part of the concavo-convex surface, and the p-side electrode is absent in the upper part of the convex part.

19. The nitride semiconductor light emitting element of claim 1, wherein the material of the p-side electrode is an Al alloy containing an element enhancing the heat resistance of Al.

20. The nitride semiconductor light emitting element of claim 19, wherein the element enhancing the heat resistance of Al is selected from the group consisting of Ti, Si, Nd and Cu.

21. The nitride semiconductor light emitting element of claim 19, wherein the material of the p-side electrode is an Al alloy containing Ti.

2-5. -5. (canceled)

8. (canceled)

12. (canceled)

14. A method for producing a nitride semiconductor light emitting element comprising an element structure wherein a laminate including one light emitting part having nitride semiconductor layers is grown on a substrate, which comprises at least

a step of growing a first n-type layer, an active layer, a p-type layer and a second n-type layer in this order on the substrate,

a step of applying dry etching to the upper surface of said second n-type layer, and

a step of forming a p-side electrode on the surface of the second n-type layer which has been exposed by dry etching in said step, the electrode being used for injecting a hole into the p-type layer of the light emitting part, the p-side electrode being formed by using a material selected from the group consisting of Al, Ti, W, Cr and ITO, and

wherein the laminate is formed by sequentially growing nitride semiconductor layers on the substrate,

when the substrate is on the lower side, the light emitting part is included in the laminate in such a manner that the first n-type layer is on the lower side and the p-type layer is on the upper side, and

the second n-type layer is located at the upper side of the light emitting part.

15. (canceled)

17. (canceled)