Light-emitting devices

• US 9,472,725 B2
• Filed: 05/06/2015
• Issued: 10/18/2016
• Est. Priority Date: 08/30/2010
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Chen, Chao-Hsing, Yang, Yu-Chen, Jou, Li-Ping, Yeh, Hui-Chun, Ku, Yi-Wen
• Primary Examiner(s): Sarkar, Asok K
• Application Number:
  US14/705,453
• Publication Number:
  US 20150236208A1
• Time in Patent Office: 531 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 33/0012 p-i-n devices
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light-emitting device comprises a semiconductor layer sequence comprising a first semiconductor layer having a first electrical conductivity, a second semiconductor layer having a second electrical conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer; a plurality of protruding structures; a plurality of beveled trenches in the semiconductor layer sequence and respectively accommodating the plurality of protruding structures; a dielectric layer on the second semiconductor layer and an inner sidewall of the plurality of beveled trenches, wherein the dielectric layer comprises a surface perpendicular to a thickness direction of the semiconductor layer sequence; a metal layer formed along the inner sidewall of the plurality of beveled trenches and extending to the surface of the dielectric layer, wherein the metal layer is insulated from the second semiconductor layer by the dielectric layer; and a first electrode formed on the plurality of protruding structures.

Claims

1. A light-emitting device, comprising:

a semiconductor layer sequence comprising a first semiconductor layer having a first electrical conductivity, a second semiconductor layer having a second electrical conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer;

a plurality of protruding structures;

a plurality of beveled trenches in the semiconductor layer sequence and respectively accommodating the plurality of protruding structures, the plurality of beveled trenches comprising a top end, a bottom end, and an inner sidewall connecting the top end and the bottom end, the top end comprising a width larger than that of the bottom end;

a dielectric layer on the second semiconductor layer and the inner sidewall of the plurality of beveled trenches, wherein the dielectric layer comprises a surface perpendicular to a thickness direction of the semiconductor layer sequence, and the dielectric layer comprises an opening on the bottom end to expose the first semiconductor layer; and

a metal layer formed along the inner sidewall of the plurality of beveled trenches and extending to the surface of the dielectric layer, wherein the metal layer is insulated from the second semiconductor layer by the dielectric layer.

2. The light-emitting device according to claim 1, wherein the plurality of protruding structures is surrounded by the metal layer.

3. The light-emitting device according to claim 1, wherein the metal layer is formed between the plurality of protruding structures and the dielectric layer.

4. The light-emitting device according to claim 1, wherein the plurality of protruding structures directly contacts with the first semiconductor layer.

5. The light-emitting device according to claim 1, wherein part of the first metal layer contacts with the plurality of protruding structures.

6. The light-emitting device according to claim 1, wherein the plurality of protruding structures comprises a layer sequence substantially same as the semiconductor layer sequence.

7. The light-emitting device according to claim 1, wherein the plurality of protruding structures and the plurality of beveled trenches comprise a similar shape from a top view of the light-emitting device.

8. The light-emitting device according to claim 1, wherein a circumference of one of the plurality of protruding structures is smaller than a circumference of one of the plurality of beveled trenches.

9. The light-emitting device according to claim 1, wherein the material of the plurality of protruding structures comprises metal.

10. The light-emitting device according to claim 1, wherein the inner sidewall of the plurality of beveled trenches comprises an inclined surface.

11. The light-emitting device according to claim 1, wherein the active layer comprises InGaN-based material, AlGaAs-based material, or AlInGaP-based material.

12. The light-emitting device according to claims 1, further comprising a carrier substrate and a connection layer formed between the carrier substrate and the semiconductor layer sequence, wherein the material of the connection layer comprises metal.

13. The light-emitting device according to claim 12, wherein the carrier substrate is conductive.

14. The light-emitting device according to claim 12, wherein the connection layer is formed between the metal layer and the carrier substrate.

15. The light-emitting device according to claim 1, further comprising a reflecting layer contacting the second semiconductor layer, wherein the metal layer is insulated from the reflecting layer by the dielectric layer.

16. The light-emitting device according to claim 15, further comprising a second electrode electrically connected to the second semiconductor layer, wherein the reflecting layer comprises a portion beyond the semiconductor layer sequence and the second electrode is on the portion of the reflecting layer.

17. The light-emitting device according to claim 15, wherein the reflecting layer comprises metal material.

18. The light-emitting device according to claim 1, further comprising a second electrode electrically connected to the second semiconductor layer.

19. The light-emitting device according to claim 1, further comprising a first electrode formed on the plurality of protruding structures.