Vertical topology light emitting device

• US 8,022,386 B2
• Filed: 12/20/2005
• Issued: 09/20/2011
• Est. Priority Date: 04/09/2002
• Status: Expired due to Fees

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yoo, Myung Cheol
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US11/311,229
• Publication Number:
  US 20060097277A1
• Time in Patent Office: 2,100 Days
• Field of Search: 257 79-103, 257/13, 257/E33.008, 257/E33.012, 257/E33.013, 257/E33.025, 257/E33.028, 257/E33.034
• US Class Current: 257/13
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/54 having a particular shape
• 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
• CPC Class Codes: H01L 33/641 characterized by the materials
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

In a vertical topology light emitting device, an adhesion layer or adhesion structure is provided between one of the electrodes and the metal contact pad associated with that electrode. The vertical topology light emitting device further comprises a support layer, a reflective structure, which also serves as the other electrode, over the support layer, and a semiconductor device including an n-type GaN-based layer, an active layer and a p-type GaN-based layer. In certain embodiments, the adhesion layer, or adhesion structure, may comprise two layers, for example, a Cr layer and an Au layer. In other embodiments, the vertical topology device may comprise an adhesion layer, or structure, between the reflective structure and the support structure.

Claims

1. A vertical topology light emitting device, comprising:

a reflective structure;

a light emitting structure having an n-type GaN-based layer, an active layer and a p-type GaN-based layer over a first side of the reflective structure,

wherein the reflective structure is positioned to reflect light emitted from the light emitting structure and the reflective structure also serves as a first electrode;

a second electrode over the light emitting structure;

a metal contact pad over the second electrode;

an inter-layer between the second electrode and the metal contact pad, wherein the inter-layer is configured to enhance adhesion between the second electrode and the metal contact pad; and

a support structure over a second side of the reflective structure.

2. The vertical topology light emitting device according to claim 1, wherein the active layer includes AlInGaN.

3. The vertical topology light emitting device according to claim 1, wherein the active layer includes a quantum well.

4. The vertical topology light emitting device according to claim 1, wherein the second electrode comprises a p-transparent contact and a p-type contact That are over the p-type GaN-based layer.

5. The vertical topology light emitting device according to claim 1, further including an adhesion structure between the reflective structure and the support structure.

6. The vertical topology light emitting device according to claim 5, wherein the adhesion structure includes Cr.

7. The vertical topology light emitting device according to claim 6, wherein the thickness of the adhesion structure including Cr is less than about 30 nm.

8. The vertical topology light emitting device according to claim 5, wherein the adhesion structure includes Au.

9. The vertical topology light emitting device according to claim 8, wherein the thickness of the adhesion structure including Au is less than about 100 nm.

10. The vertical topology light emitting device according to claim 5, wherein the adhesion structure and the support structure have surfaces that face each other, and wherein the surface areas of the surfaces are substantially the same.

11. The vertical topology light emitting device according to claim 10, wherein the adhesion structure surface and the support structure surface contact each other.

12. The vertical topology light emitting device according to claim 5, wherein the adhesion structure is configured to enhance bonding between the reflective structure and the support structure.

13. The vertical topology light emitting device according to claim 1, wherein the reflective structure includes aluminum.

14. The vertical topology light emitting device according to claim 1, wherein the support structure is less than 100 microns thick.

15. The vertical topology light emitting device according to claim 1, wherein the support structure includes at least one of Cu, Au, or Al.

16. The vertical topology light emitting device according to claim 1, wherein the n-type GaN-based layer of the light emitting structure is closer to the reflective structure than the p-type GaN-based layer of the light emitting structure.

17. The vertical topology light emitting device according to claim 1, wherein the metal contact pad includes at least one of Pd, Pt, Au, or Al.

18. The vertical topology light emitting device according to claim 1, wherein the inter-layer includes at least one of Cr or Au.

19. The vertical topology light emitting device according to claim 1, wherein the light emitting structure contacts the first side of the reflective structure.

20. The vertical topology light emitting device according to claim 1, wherein the second electrode comprises a transparent contact.

21. The vertical topology light emitting device according to claim 1, wherein the support structure comprises a metallic layer.

42. The vertical topology light emitting device according to claim 1, wherein the reflective structure includes titanium.

22. A vertical topology light emitting device, comprising:

a support layer;

a first adhesion structure over the support layer, the first adhesion structure comprising two layers;

a reflective structure over the first adhesion structure;

a semiconductor device including an n-type GaN-based layer, an active layer and a p-type GaN-based layer, wherein the semiconductor device is over the reflective structure,

a first electrode over the semiconductor device;

a metal contact pad over the first electrode; and

a second adhesion structure between the first electrode and the metal contact pad, wherein the reflective structure is positioned to reflect light emitted from the semiconductor device and the reflective structure also serves as a second electrode.

23. The vertical topology light emitting device according to claim 22, wherein the reflective structure includes titanium.

24. The vertical topology light emitting device according to claim 22, wherein the reflective structure includes aluminum.

25. The vertical topology light emitting device according to claim 22, wherein the metal contact pad includes at least one of Pd, Pt, Au, Cr, or Al.

26. The vertical topology light emitting device according to claim 22, wherein the n-type GaN-based layer of the semiconductor device is closer to the reflective structure than the p-type GaN-based layer of the semiconductor device.

27. The vertical topology light emitting device according to claim 22, wherein the support layer comprises a metallic layer.

28. The vertical topology light emitting device according to claim 22, wherein the support layer comprises at least one of Cu, Au, or Al.

29. The vertical topology light emitting device according to claim 22, wherein the semiconductor device contacts the reflective structure.

30. The vertical topology light emitting device according to claim 22, wherein the first adhesion structure and the support layer have surfaces that face each other, and wherein the surface areas of the surfaces are substantially the same.

31. The vertical topology light emitting device according to claim 30, wherein the first adhesion structure surface and the support layer surface contact each other.

32. The vertical topology light emitting device according to claim 22, wherein the first adhesion structure includes a Cr adhesion layer.

33. The vertical topology light emitting device according to claim 32, wherein the thickness of the Cr adhesion layer is less than about 30 nm.

34. The vertical topology light emitting device according to claim 22, wherein the first adhesion structure includes an Au adhesion layer.

35. The vertical topology light emitting device according to claim 34, wherein the thickness of the Au adhesion layer is less than about 100 nm.

36. The vertical topology light emitting device according to claim 22, wherein the first adhesion structure is configured to enhance bonding between the reflective structure and the support layer.

37. The vertical topology light emitting device according to claim 22, wherein the first electrode comprises a p-transparent contact and a p-type contact that are over the p-type GaN-based layer.

38. The vertical topology light emitting device according to claim 22, wherein the first electrode comprises a transparent contact.

39. The vertical topology light emitting device according to claim 22, wherein the support layer is less than 100 microns thick.

40. The vertical topology light emitting device according to claim 22, wherein the second adhesion structure comprises two metallic layers.

41. The vertical topology light emitting device according to claim 22, wherein the second adhesion structure comprises at least one of Cr or Au.