Light emitting diode

• US 8,008,646 B2
• Filed: 05/18/2007
• Issued: 08/30/2011
• Est. Priority Date: 06/16/2005
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation), LG Innotek Company Limited (LG Corporation)
• Inventors: Leem, See jong
• Primary Examiner(s): SEFER, AHMED N
• Application Number:
  US11/802,073
• Publication Number:
  US 20070267644A1
• Time in Patent Office: 1,565 Days
• Field of Search: 257/13, 257 81- 82, 257 98- 99
• US Class Current: 257/13
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A light emitting diode is disclosed, wherein the light extraction efficiency of a device can be enhanced by forming patterns on a substrate, a light emitting structure is formed on the substrate formed with the patterns, the substrate is removed from the light emitting structure, and patterns corresponding to those formed on the substrate are formed on the light emitting structure.

Claims

1. A vertical topology light emitting diode, comprising:

a support layer;

a bonding layer on the support layer;

a UBM layer on the bonding layer, the UBM layer having a multi-layer structure, wherein the UBM layer has a surface facing the bonding layer, and wherein the shortest distance between the surface of the UBM layer and the support structure is substantially constant over the entire surface of the UBM layer;

a first electrode on the UBM layer;

a first-type semiconductor layer on the first electrode;

an active layer on the first-type semiconductor layer;

a second-type semiconductor layer on the active layer, the second-type semiconductor layer comprising a light extraction pattern having a non-periodic structure; and

a second electrode on the second-type semiconductor layer.

2. The vertical topology light emitting diode as defined in claim 1, wherein the UBM layer comprises at least two metals of Ti, Pt, Ni, and Au.

3. The vertical topology light emitting diode as defined in claim 1, further comprising a reflection layer on the first electrode.

4. The vertical topology light emitting diode as defined in claim 3, wherein the reflection layer comprises as least one material of Ag, Al, Pt, Au, Ni, Ti, and transmissive conductive oxide.

5. The vertical topology light emitting diode as defined in claim 3, wherein the reflection layer contacts the UBM layer.

6. The vertical topology light emitting diode as defined in claim 1, wherein the support layer comprises:

a conductive layer; and

an electrical contact on at least one surface of the conductive layer.

7. The vertical topology light emitting diode as defined in claim 6, wherein the conductive layer comprises at least one material of Si, AlN, SiC, GaAs, Cu, W and Mo.

8. The vertical topology light emitting diode as defined in claim 1, wherein the bonding layer comprises solder.

9. The vertical topology light emitting diode as defined in claim 1, wherein the bonding layer is located between the support layer and the UBM layer.

10. The vertical topology light emitting diode as defined in claim 1, wherein the UBM layer is located between the first electrode and the bonding layer.

11. The vertical topology light emitting diode as defined in claim 1, wherein the bonding layer is configured to enhance adhesion between the UBM layer and the support layer.

12. The vertical topology light emitting device as defined in claim 1, wherein the first-type semiconductor layer is a p-GaN layer and the second-type semiconductor layer is an n-GaN layer.

13. The vertical topology light emitting diode as defined in claim 1, wherein a height of the light extraction pattern is in the range of 0.001˜

100 μ

m.

14. The vertical topology light emitting diode as defined in claim 1, wherein the bonding layer contacts the surface of the UBM layer.

15. The vertical topology light emitting diode as defined in claim 1, wherein the surface of the UBM layer is substantially planar.

16. A vertical topology light emitting diode comprising:

a semiconductor sub-mount having at least one electrical contact;

a UBM layer on the sub-mount, the UBM layer comprising at least two metals;

a first electrode on the UBM layer;

a semiconductor layer having a multi-layer structure, the semiconductor layer comprising a light extraction pattern having a periodic structure and non-periodic structures within the periodic structure; and

a second electrode on the semiconductor layer.

17. The vertical topology light emitting diode as defined in claim 16, further comprising a reflection layer on the first electrode.

18. The vertical topology light emitting diode as defined in claim 17, wherein the reflection layer comprises as least one material of Ag, Al, Pt, Au, Ni, Ti, and transmissive conductive oxide.

19. The vertical topology light emitting diode as defined in claim 16, wherein the UBM layer comprises at least one material of Ti, Pt, Ni, and Au.

20. The vertical topology light emitting diode as defined in claim 16, further comprising a bonding layer located between the sub-mount and the UBM layer.

21. The vertical topology light emitting diode as defined in claim 20, wherein the bonding layer is configured to enhance adhesion between the UBM layer and the sub-mount.

22. The vertical topology light emitting diode as defined in claim 20, wherein the bonding layer comprises solder.

23. The vertical topology light emitting diode as defined in claim 20, wherein the UBM layer is located between the first electrode and the bonding layer.

24. The vertical topology light emitting diode as defined in claim 20, wherein the UBM layer has a surface facing the bonding layer.

25. The vertical topology light emitting diode as defined in claim 24, wherein the shortest distance between the surface of the UBM layer and the sub-mount is substantially constant over the entire surface of the UBM layer.

26. The vertical topology light emitting diode as defined in claim 24, wherein the bonding layer contacts the surface of the UBM layer.

27. The vertical topology light emitting diode as defined in claim 24, wherein the surface of the UBM layer is substantially planar.

28. The vertical topology light emitting diode as defined in claim 16, wherein a height of the light extraction pattern is in the range of 0.001˜

100 μ

m.