Light emitting element

• US 6,809,340 B2
• Filed: 09/19/2002
• Issued: 10/26/2004
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Kato, Hideaki, Suehiro, Yoshinobu
• Primary Examiner(s): Pham, Long
• Assistant Examiner(s): LOUIE, WAI SING
• Application Number:
  US10/246,409
• Publication Number:
  US 20030062529A1
• Time in Patent Office: 768 Days
• Field of Search: 257/13, 257/79, 257/80, 257/82, 257/89, 257/93, 257/98, 257/99, 257/103, 257/918, 257/91
• US Class Current: 257/79
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/38 with a particular shape

Abstract

Irregularities are formed on at least a side surface of a light emitting layer of a light emitting element. In one form of the invention, an n-type layer which is a Group-III nitride compound semiconductor or the like, a light emitting layer, and a p-type layer are successively formed on a sapphire substrate through MOVPE or the like. Then, dry etching is carried out to expose the n-type layer to form a pedestal electrode. In this etching process, an etching pattern is employed to form a wave shape on the periphery of the p-type layer.

Claims

1. A solid light emitting element comprising:

a light emitting region having at least one layer,

wherein at least a portion of a side surface of the light omitting region is continuously concave/convex.

2. A light emitting element as claimed in claim 1, wherein the portion of the side surface comprises continuously concave/convex curves of varying curvature.

3. A light emitting element as claimed in claim 1, wherein the portion of the side surface, which is continuously concave/convex, is tapered at an angle with respect to the light emitting region.

4. A light emitting element as claimed in claim 2, wherein the portion of the side surface, which is continuously concave/convex, is tapered at an angle with respect to the light emitting region.

5. A light emitting element as claimed in claim 1, wherein the portion of the side surface, which is continuously concave/convex, is formed by etching.

6. A light emitting element as claimed in claim 4, wherein the portion of the side surface, which is continuously concave/convex, is formed by etching.

7. A light emitting element as claimed in claim 1, wherein the portion of the side surface, which is continuously concave/convex, is formed by patterning of the light emitting region.

8. A light emitting element as claimed in claim 6, wherein the portion of the side surface, which is continuously concave/convex, is formed by patterning of the light emitting region.

9. A light emitting element as claimed in claim 1, wherein the portion of the side surface, which is continuously concave/convex, is formed when the light emitting element is separated from another light emitting element.

10. A light emitting element as claimed in claim 8, wherein the side surface, which is continuously concave/convex, is formed when the light emitting element is separated from another light emitting element.

11. A light emitting element as claimed in claim 1, wherein the light emitting element is formed atop a substrate, and the refractive index of the substrate is smaller than the refractive index of the light emitting region.

12. A light emitting element as claimed in claim 10, wherein the light emitting element is formed atop a substrate, and the refractive index of the substrate is smaller than the refractive index of the light emitting region.

13. A light emitting element as claimed in claim 1, wherein each layer formed on the substrate comprises a Group-III nitride compound semiconductor.

14. A light emitting element as claimed in claim 11, wherein each layer formed on the substrate comprises a Group III nitride compound semiconductor.

15. A light emitting element as claimed in claim 1, wherein a top surface of the light emitting element is continuously concave/convex.

16. A light emitting element as claimed in claim 14, wherein at least a portion of a top surface of the light emitting element is continuously concave/convex.