Light-emitting devices

• US 10,304,999 B2
• Filed: 12/19/2017
• Issued: 05/28/2019
• Est. Priority Date: 08/30/2010
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Chen, Chao-Hsing, Yang, Yu-Chen, Jou, Li-Ping, Yeh, Hui-Chun, Ku, Yi-Wen
• Primary Examiner(s): Sarkar, Asok K
• Application Number:
  US15/846,773
• Publication Number:
  US 20180108807A1
• Time in Patent Office: 525 Days
• Field of Search: None
• 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 beveled trenches formed in the semiconductor layer sequence; a plurality of protruding structures respectively formed in the plurality of beveled trenches; a dielectric layer formed on the second semiconductor layer and an inner sidewall of the plurality of beveled trenches; a reflecting layer interposed between the semiconductor layer sequence and the dielectric layer; and a metal layer formed along the inner sidewall of the plurality of beveled trenches, wherein the dielectric layer, the reflecting layer and the metal layer are overlapping, the plurality of protruding structures and the reflecting layer are not overlapping.

Claims

1. A light-emitting device, comprising:

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

a beveled trench formed in the semiconductor layer sequence, comprising a top end, a bottom end exposing the first semiconductor layer and an inner sidewall connecting the top end and the bottom end;

a protruding structure formed inside the beveled trench and protruding outside the top end of the beveled trench in a thickness direction of the semiconductor layer sequence;

a dielectric layer formed on the second semiconductor layer and the inner sidewall of the beveled trench;

a reflecting layer interposed between the second semiconductor layer and the dielectric layer; and

a metal layer formed along the inner sidewall of the beveled trench to extend outside the beveled trench, wherein the dielectric layer, the reflecting layer and the metal layer are overlapping.

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

3. The light-emitting device according to claim 1, wherein the metal layer and the protruding structure are overlapping.

4. The light-emitting device according to claim 1, further comprising a plurality of beveled trenches and a plurality of protruding structures respectively formed in the plurality of beveled trenches, wherein the plurality of protruding structures are separated from each other in a cross-sectional view of the light-emitting device, and the metal layer comprises a circular shape in a top view of the light-emitting device.

5. The light-emitting device according to claim 4, further comprising a first electrode formed on the plurality of protruding structures.

6. The light-emitting device according to claim 5, 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.

7. The light-emitting device according to claim 6, wherein the reflecting layer comprises metal material.

8. The light-emitting device according to claim 1, wherein the dielectric layer comprises a surface perpendicular to the thickness direction of the semiconductor layer sequence, and the metal layer extends onto the surface of the dielectric layer.

9. The light-emitting device according to claim 1, wherein the protruding structure does not form on the second semiconductor layer.

10. The light-emitting device according to claim 1, wherein the protruding structure and the beveled trench comprise a similar shape from a top view of the light-emitting device.

11. The light-emitting device according to claim 10, wherein a circumference of the protruding structure is smaller than a circumference of the beveled trench.

12. The light-emitting device according to claim 1, wherein the material of the protruding structure comprises metal.

13. The light-emitting device according to claim 1, wherein the top end comprises an area larger than an area of the bottom end.

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

15. The light-emitting device according to claim 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.

16. The light-emitting device according to claim 15, wherein the carrier substrate is conductive.

17. The light-emitting device according to claim 15, wherein the connection layer is formed between the metal layer and the carrier substrate.

18. 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 beveled trench formed in the semiconductor layer sequence;

a protruding structure only formed at the beveled trench;

a dielectric layer formed on the second semiconductor layer and an inner sidewall of the beveled trench;

a reflecting layer interposed between the semiconductor layer sequence and the dielectric layer;

a metal layer formed along the inner sidewall of the beveled trench and extended outside the beveled trench;

a carrier substrate; and

a void formed at a position under and corresponding to a position of the beveled trench.

19. The light-emitting device according to claim 18, wherein the dielectric layer, the reflecting layer and the metal layer are overlapping, and the protruding structure and the reflecting layer are not overlapping.

20. The light-emitting device according to claim 18, further comprising a first connection layer between the carrier substrate and the metal layer, wherein the void is between the metal layer and the first connection layer.