Light-emitting device having a patterned substrate and the method thereof

• US 10,374,125 B2
• Filed: 07/30/2018
• Issued: 08/06/2019
• Est. Priority Date: 07/28/2006
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Hsu, Ta-Cheng, Yeh, Ching-Shian, Huang, Chao-Shun, Su, Ying-Yong, Yang, Ya-Lan, Lee, Ya-Ju
• Primary Examiner(s): Raleigh, Donald L
• Application Number:
  US16/049,337
• Publication Number:
  US 20190067518A1
• Time in Patent Office: 372 Days
• Field of Search: 257 95, 313498
• 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

A light-emitting device comprises a textured substrate comprising a plurality of textured structures, wherein the textured structures and the textured substrate are both composed of sapphire; and a light-emitting stack overlaying the textured substrate, comprising a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, wherein each of the plurality of textured structures comprises a top portion having a first top-view shape, and a bottom portion parallel to the top portion and having a second top-view shape, wherein the first top-view shape comprises a circle or an ellipse, the first top-view shape comprises a first periphery and the second top-view shape comprises a second periphery, the first periphery is enclosed by the second periphery, and various distances are between each of the first periphery and the second periphery.

Claims

1. A light-emitting device, comprising:

a sapphire substrate comprising a flat surface, a lower surface, and a plurality of depressions between the flat surface and the lower surface;

a semiconductor buffer layer filled the plurality of depressions and formed on the flat surface; and

a light-emitting stack comprising III-V semiconductor, overlaying the semiconductor buffer layer, comprising a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer,

wherein in a plan view of the light-emitting device, one of the plurality of depressions comprises an opening top portion having a first top-view shape and a bottom portion having a second top-view shape,

wherein in a cross-sectional view of the light-emitting device, the one of the plurality of depressions comprises a sidewall portion connecting the opening top portion and the bottom portion, and

wherein in a cross-sectional view of the light-emitting device, the sidewall portion near the opening top portion or the bottom portion is a curve.

2. The light-emitting device according to claim 1, wherein the opening top portion is closer to the light-emitting stack than the bottom portion to the light-emitting stack.

3. The light-emitting device according to claim 1, wherein the first top-view shape is different from the second top-view shape.

4. The light-emitting device according to claim 1, wherein the first top-view shape comprises a circle or an ellipse.

5. The light-emitting device according to claim 1, wherein the second top-view shape comprises a triangle.

6. The light-emitting device according to claim 1, wherein the semiconductor buffer layer comprises Ill-nitride materials.

7. The light-emitting device according to claim 6, wherein the semiconductor buffer layer comprises AN.

8. The light-emitting device according to claim 1, wherein the sidewall portion comprises three symmetric planes.

9. The light-emitting device according to claim 1, wherein the bottom portion comprises an area smaller than an area of the opening top portion.

10. The light-emitting device according to claim 1, wherein the bottom portion is flat.

11. A light-emitting device, comprising:

a sapphire substrate comprising a flat surface, a lower surface, and a plurality of depressions between the flat surface and the lower surface;

a semiconductor buffer layer filled the plurality of depressions and formed on the flat surface; and

a light-emitting stack comprising III-V semiconductor, overlaying the semiconductor buffer layer, comprising a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer,

wherein in a plan view of the light-emitting device, one of the plurality of depressions comprises an opening top portion having a top-view shape,

wherein in a cross-sectional view of the light-emitting device, the one of the plurality of depressions comprises a plurality of sidewall planes intersected at a bottom point, and

wherein in a cross-sectional view of the light-emitting device, the sidewall portion near the opening top portion or the bottom portion is a curve.

12. The light-emitting device according to claim 11, wherein the opening top portion is closer to the light-emitting stack than the bottom point to the light-emitting stack.

13. The light-emitting device according to claim 11, wherein the top-view shape comprises a circle or an ellipse.

14. The light-emitting device according to claim 11, wherein the semiconductor buffer layer comprises Ill-nitride materials.

15. The light-emitting device according to claim 14, wherein the semiconductor buffer layer comprises AlN.

16. The light-emitting device according to claim 11, wherein the plurality of sidewall planes comprises sapphire R plane.

17. The light-emitting device according to claim 11, wherein the flat surface comprises sapphire C plane.