Light emitting device and method for manufacturing the same

• US 8,288,786 B2
• Filed: 11/06/2009
• Issued: 10/16/2012
• Est. Priority Date: 11/24/2008
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Hwang, Sung Min, Cho, Hyun Kyong, Park, Gyeong Geun
• Primary Examiner(s): Lee, Cheung
• Assistant Examiner(s): Joy, Jeremy
• Application Number:
  US12/614,240
• Publication Number:
  US 20100127303A1
• Time in Patent Office: 1,075 Days
• Field of Search: 257/98, 257/E33.001, 257/E33.005, 257/E33.007, 257/E33.062, 257/E33.065, 257/E33.067, 438/29
• US Class Current: 257/98
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light emitting device according to an embodiment includes a second electrode layer comprising at least one projection part; at least one current blocking layer on the projection part of the second electrode layer; a second conductive type semiconductor layer on the second electrode layer and the current blocking layer; an active layer on the second conductive type semiconductor layer; a first conductive type semiconductor layer on the active layer; and a first electrode layer on the first conductive type semiconductor layer, at least a portion of the first electrode layer corresponding with the current blocking layer in a vertical direction.

Claims

1. A light emitting device, comprising:

a second electrode layer comprising at least one projection part;

a current blocking layer on the projection part of the second electrode layer;

a second conductive type semiconductor layer on the second electrode layer and the current blocking layer;

an active layer on the second conductive type semiconductor layer;

a first conductive type semiconductor layer on the active layer; and

a first electrode layer on the first conductive type semiconductor layer, at least a portion of the first electrode layer corresponding with the current blocking layer in a vertical direction.

2. The light emitting device according to claim 1, wherein the current blocking layer extends along a central portion of the second electrode layer and/or surrounds at least a portion of a periphery of the second electrode layer.

3. The light emitting device according to claim 1, wherein the projection part is disposed at a central portion of the second electrode layer and/or a peripheral portion of the second electrode layer.

4. The light emitting device according to claim 1, wherein the current blocking layer is formed of at least one of titanium (Ti), zirconium (Zr), chrome (Cr), gold (Au) or tungsten (W), or an alloy comprising at least one of titanium (Ti), zirconium (Zr), chrome (Cr), gold (Au) or tungsten (W).

5. The light emitting device according to claim 1, wherein the current blocking layer includes a first current blocking layer disposed on the projection part of the second electrode layer, and a second current blocking layer disposed at an indented area of the second electrode layer.

6. The light emitting device according to claim 5, wherein the first current blocking layer is disposed at a central portion of the second electrode layer, and the second current blocking layer is disposed at a peripheral portion of the second electrode layer.

7. The light emitting device according to claim 1, wherein the projection part includes a plurality of projection parts, and the current blocking layer includes a plurality of current blocking layers spaced apart from each other and disposed respectively on the plurality of projection parts.

8. The light emitting device according to claim 7, wherein the plurality of current block layers are disposed at a central portion of the second electrode layer and at least one peripheral portion of the second electrode layer.

9. The light emitting device according to claim 1, wherein the current blocking layer forms a schottky contact with the second conductive type semiconductor layer, and the second electrode layer forms an ohmic contact with the second conductive type semiconductor layer.

10. The light emitting device according to claim 1, wherein the current blocking layer is disposed on a curved surface or slanted surfaces of the projection part.

11. A light emitting device, comprising:

a second electrode layer;

a current blocking layer the second electrode layer;

a second conductive type semiconductor layer on the second electrode layer and the current blocking layer;

an active layer on the second conductive type semiconductor layer;

a first conductive type semiconductor layer on the active layer; and

a first electrode layer on the first conductive type semiconductor layer,

wherein the current blocking layer is disposed on the second electrode layer and has a substantially triangular shape.

12. The light emitting device according to claim 11, wherein the current blocking layer is disposed on a central portion of the second electrode layer and at least one peripheral portion of the second electrode layer.

13. The light emitting device according to claim 11, wherein the current block layer is overlapped with the first electrode layer in a vertical direction.

14. The light emitting device according to claim 11, wherein the current blocking layer forms a schottky contact with the second conductive type semiconductor layer and the second electrode layer forms an ohmic contact with the second conductive type semiconductor layer.

15. A light emitting device, comprising:

a second electrode layer comprising a projection part;

a first current blocking layer on the second electrode layer;

a second conductive type semiconductor layer on the second electrode layer and the first current blocking layer;

an active layer on the second conductive type semiconductor layer;

a first conductive type semiconductor layer on the active layer; and

a first electrode layer on the first conductive type semiconductor layer,

wherein the first current blocking layer is disposed on the projection part of the second electrode layer.

16. The light emitting device according to claim 15, wherein the first current blocking layer is disposed directly on the second electrode layer and has a shape substantially corresponding with the projection part.

17. The light emitting device according to claim 15, wherein the first current blocking layer is aligned with the first electrode layer.

18. The light emitting device according to claim 15, wherein the first current blocking layer is overlapped with the first electrode layer in a vertical direction and the first conductive semiconductor layer includes an n-type impurity.

19. The light emitting device according to claim 18, further comprising:

a second current blocking layer spaced apart from the first current blocking layer, and formed on another projected part of the second electrode layer or in an indented area of the second electrode layer.

20. The light emitting device according to claim 19, wherein at least one of the first and second current blocking layers forms a schottky contact with the second conductive type semiconductor layer.

21. The light emitting device according to claim 20, wherein at least one of the first and second current blocking layers is formed of at least one of titanium (Ti), zirconium (Zr), chrome (Cr), gold (Au) or tungsten (W), or an alloy comprising at least one of titanium (Ti), zirconium (Zr), chrome (Cr), gold (Au) or tungsten (W).