Light emitting device having a patterned substrate and the method thereof

• US 7,825,577 B2
• Filed: 07/30/2007
• Issued: 11/02/2010
• Est. Priority Date: 07/28/2006
• Status: Active Grant

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: Hsu, Ta-Cheng, Su, Ying-Yong, Lee, Ya-Ju, Yang, Ya-Lan, Huang, Chao-Shun, Yeh, Ching-Shian
• Primary Examiner(s): Williams; Joseph L
• Assistant Examiner(s): Lee; Brenitra M
• Application Number:
  US11/878,961
• Publication Number:
  US 20080067916A1
• Time in Patent Office: 1,191 Days
• Field of Search: 313495-498, 438/44, 257/30
• US Class Current: 313/498
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

This disclosure provides a light-emitting device including a patterned substrate and the manufacturing method thereof. The patterned substrate has a plurality of depressions and/or extrusions for scattering light emitted from a light-emitting layer. Each of the plurality of depressions and/or extrusions comprises a top portion, a bottom portion, and a sidewall portion enclosing the top portion and the bottom portion, and at least part of the sidewall portion comprises a curve. In a preferred embodiment, the light-emitting device further comprises a rough surface formed on at least one of the top portion, the bottom portion, and the sidewall portion.

Claims

1. A light-emitting device, comprising

a patterned substrate having an uneven surface composed of a plurality of depressions and/or extrusions;

a light-emitting stack overlaying the patterned substrate, comprising a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer,

wherein at least one of the plurality of depressions and/or extrusions comprises a top portion, a bottom portion, and a sidewall portion, and at least part of the sidewall portion comprises a curve, and

wherein said top portion is substantially parallel to said bottom portion and includes a rough surface.

2. The light-emitting device according to claim 1, wherein the sidewall portion comprises a plurality of symmetric planes.

3. The light-emitting device according to claim 1, wherein at least one of the top portion and the bottom portion comprises a flat plane.

4. The light-emitting device according to claim 1, wherein the substrate comprises sapphire.

5. The light-emitting device according to claim 4, wherein the bottom portion comprises a sapphire C plane.

6. The light-emitting device according to claim 4, wherein the sidewall portion comprises at least three symmetric sapphire R planes.

7. The light-emitting device according to claim 1, wherein the top-view pattern of the depression and/or extrusion comprises circle or ellipse.

8. The light-emitting device according to claim 1, wherein the light-emitting stack comprises a III-nitride compound.

9. The light-emitting device according to claim 1, wherein the rough surface comprises a regular pattern or an irregular pattern.

10. A light-emitting device, comprising

a patterned substrate having an uneven surface composed of a plurality of depressions and/or extrusions;

a light-emitting stack overlaying the patterned substrate, comprising a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, wherein at least one of the plurality of depressions and/or extrusions comprises a top portion, a bottom portion, and

wherein said top portion is substantially parallel to said bottom portion and includes a rough surface.

11. The light-emitting device according to claim 10, wherein the rough surface comprises a regular pattern or an irregular pattern.

12. The light-emitting device according to claim 10, wherein at least part of the sidewall portion comprises a curve.

13. The light-emitting device according to claim 10, wherein the sidewall portion comprises a plurality of symmetric planes.

14. The light-emitting device according to claim 10, wherein the substrate comprises sapphire.

15. The light-emitting device according to claim 14, wherein the bottom portion comprises a sapphire C plane.

16. The light-emitting device according to claim 14, wherein the sidewall portion comprises at least three symmetric sapphire R planes.

17. The light-emitting device according to claim 10, wherein the top-view pattern of the depression and/or extrusion comprises circle or ellipse.

18. The light-emitting device according to claim 10, wherein the light-emitting stack comprises a III-nitride compound.