Light-emitting diode and method for manufacturing the same

• US 20070221927A1
• Filed: 02/22/2007
• Published: 09/27/2007
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epitech Technology Corp. (Epistar Corporation)
• Inventors: Chen, Shi-Ming, Chu, Chang-Hsing, Houng, Mau-Phon, Yen, Te-Chi
• Granted Patent: US 7,439,091 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

A light-emitting diode (LED) and a method for manufacturing the same are described. The method for manufacturing the LED comprises the following steps. An illuminant epitaxial structure is provided, in which the illuminant epitaxial structure has a first surface and a second surface on opposite sides, and a substrate is deposed on the first surface of the illuminant epitaxial structure. A metal layer is formed on the second surface of the illuminant epitaxial structure. An anodic oxidization step is performed to oxidize the metal layer, so as to form a metal oxide layer. An etching step is performed to remove a portion of the metal oxide layer, so as to form a plurality of holes in the metal oxide layer.

Claims

1. A method for manufacturing a light-emitting diode, comprising:

providing an illuminant epitaxial structure, wherein the illuminant epitaxial structure has a first surface and a second surface on opposite sides, and a substrate is deposed on the first surface of the illuminant epitaxial structure;

forming a metal layer on the second surface of the illuminant epitaxial structure;

performing an anodic oxidization step to oxidize the metal layer, so as to form a metal oxide layer; and

performing an etching step to remove a portion of the metal oxide layer, so as to form a plurality of holes in the metal oxide layer.

2. The method for manufacturing a light-emitting diode according to claim 1, wherein a material of the metal layer is Al, Mn, Zn, Ni, Ag or Ti.

3. The method for manufacturing a light-emitting diode according to claim 1, wherein dimensions of the holes are between about 1 nm and about 1000 nm.

4. The method for manufacturing a light-emitting diode according to claim 1, wherein the etching step comprises using an etch solution, and the etch solution is a phosphoric acid solution, an oxalic acid solution or a sulfuric acid solution.

5. The method for manufacturing a light-emitting diode according to claim 1, wherein the illuminant epitaxial structure comprises a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer stacked in sequence, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer have different conductivity types.

6. The method for manufacturing a light-emitting diode according to claim 5, wherein the metal layer is located on a first portion of the second surface of the illuminant epitaxial structure, and a second portion of the second surface of the illuminant epitaxial structure is exposed.

7. The method for manufacturing a light-emitting diode according to claim 6, further comprising performing a substrate-thinned step.

8. The method for manufacturing a light-emitting diode according to claim 7, further comprising forming two metal electrodes respectively deposed on the second portion of the second surface of the illuminant epitaxial structure and an exposed surface of the substrate.

9. The method for manufacturing a light-emitting diode according to claim 6, wherein the holes expose a portion of the first portion of the second surface of the illuminant epitaxial structure.

10. The method for manufacturing a light-emitting diode according to claim 6, wherein the holes do not expose a portion of the first portion of the second surface of the illuminant epitaxial structure.

11. The method for manufacturing a light-emitting diode according to claim 6, wherein the step of providing the illuminant epitaxial structure comprises:

providing another substrate;

forming the illuminant epitaxial structure on the another substrate, wherein the another substrate is deposed on the second surface of the illuminant epitaxial structure;

deposing the substrate on the first surface of the illuminant epitaxial structure; and

removing the another substrate to expose the second surface of the illuminant epitaxial structure.

12. The method for manufacturing a light-emitting diode according to claim 11, further comprising forming two metal electrodes respectively deposed on the second portion of the second surface of the illuminant epitaxial structure and an exposed surface of the substrate.

13. The method for manufacturing a light-emitting diode according to claim 5, wherein the illuminant epitaxial structure further comprises a buffer layer located between the substrate and the first conductivity type semiconductor layer.

14. The method for manufacturing a light-emitting diode according to claim 13, further comprising removing a portion of the second conductivity type semiconductor layer and a portion of the active layer to expose a portion of the first conductivity type semiconductor layer before the step of the forming the metal layer.

15. The method for manufacturing a light-emitting diode according to claim 14, wherein the metal layer is located on a first portion of a remaining portion of the second conductivity type semiconductor layer to expose a second portion of the remaining portion of the second conductivity type semiconductor layer.

16. The method for manufacturing a light-emitting diode according to claim 15, further comprising performing a substrate-thinned step after the anodic oxidization step.

17. The method for manufacturing a light-emitting diode according to claim 15, further comprising forming two metal electrodes respectively deposed on the exposed portion of the first conductivity type semiconductor layer and the second portion of the remaining portion of the second conductivity type semiconductor layer.

18. The method for manufacturing a light-emitting diode according to claim 17, further comprising forming a transparent electrode to cover the metal oxide layer and the holes between the anodic oxidization step and the step of forming the metal electrodes.

19. The method for manufacturing a light-emitting diode according to claim 1, wherein a thickness of the metal layer is between about 1 nm and about 1000 nm.

20. The method for manufacturing a light-emitting diode according to claim 1, wherein a reaction voltage is controlled between about 2 V and about 100 V when the anodic oxidization step is performed.

21. A method for manufacturing a light-emitting diode, comprising:

providing a substrate, wherein the substrate has a first surface and a second surface on opposite sides;

forming an illuminant epitaxial structure on the first surface of the substrate, wherein the illuminant epitaxial structure comprises a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer stacked on the substrate in sequence, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer have different conductivity types;

removing a portion of the second conductivity type semiconductor layer and a portion of the active layer to expose a portion of the first conductivity type semiconductor layer;

forming a metal layer on the second surface of the substrate;

performing an anodic oxidization step to oxidize the metal layer, so as to form a metal oxide layer;

performing an etching step to remove a portion of the metal oxide layer, so as to form a plurality of holes in the metal oxide layer;

providing a sub-mount, wherein at least two bonding bumps are set on a surface of the sub-mount; and

performing a flip chip step to make the exposed portion of the first conductivity type semiconductor layer and the second conductivity type semiconductor layer respectively connect with the bonding bumps on the sub-mount.

22. The method for manufacturing a light-emitting diode according to claim 21, wherein a material of the metal layer is Al, Mn, Zn, Ni, Ag or Ti.

23. The method for manufacturing a light-emitting diode according to claim 21, wherein a thickness of the metal layer is between about 1 nm and about 1000 nm.

24. The method for manufacturing a light-emitting diode according to claim 21, wherein a reaction voltage is controlled between about 2 V and about 100 V when the anodic oxidization step is performed.

25. The method for manufacturing a light-emitting diode according to claim 21, wherein dimensions of the holes are between about 1 nm and about 1000 nm.

26. The method for manufacturing a light-emitting diode according to claim 21, wherein the holes expose a portion of the second surface of the substrate.

27. A light-emitting diode, comprising:

an illuminant epitaxial structure having a first surface and a second surface on opposite sides, and a substrate is deposed on the first surface of the illuminant epitaxial structure; and

an anodic oxidation metal layer deposed on the second surface of the illuminant epitaxial structure, wherein the anodic oxidation metal layer is formed from a metal layer, and the anodic oxidation metal layer includes a plurality of holes.

28. The light-emitting diode according to claim 27, wherein a material of the metal layer is Al, Mn, Zn, Ni, Ag or Ti.

29. The light-emitting diode according to claim 27, wherein a thickness of the metal layer is between about 1 nm and about 1000 nm.

30. The light-emitting diode according to claim 27, wherein dimensions of the holes are between about 1 nm and about 1000 nm.

31. The light-emitting diode according to claim 27, wherein the illuminant epitaxial structure comprises a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer stacked in sequence, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer have different conductivity types.

32. The light-emitting diode according to claim 31, wherein the metal layer is located on a first portion of the second surface of the illuminant epitaxial structure, and a second portion of the second surface of the illuminant epitaxial structure is exposed.

33. The light-emitting diode according to claim 32, further comprising two metal electrodes respectively deposed on the second portion of the second surface of the illuminant epitaxial structure and an exposed surface of the substrate.

34. The light-emitting diode according to claim 32, wherein the holes expose a portion of the first portion of the second surface of the illuminant epitaxial structure.

35. The light-emitting diode according to claim 32, wherein the holes do not expose a portion of the first portion of the second surface of the illuminant epitaxial structure.

36. The light-emitting diode according to claim 31, wherein a stacked structure composed of the second conductivity type semiconductor layer and the active layer is located a portion of the first conductivity type semiconductor layer to expose another portion of the first conductivity type semiconductor layer.

37. The light-emitting diode according to claim 36, wherein the metal layer is located on a first portion of the second conductivity type semiconductor layer to expose a second portion of the second conductivity type semiconductor layer.

38. The light-emitting diode according to claim 37, further comprising two metal electrodes respectively deposed on the exposed portion of the first conductivity type semiconductor layer and the second portion of the second conductivity type semiconductor layer.

39. The light-emitting diode according to claim 38, further comprising a transparent electrode covering the anodic oxidation metal layer and the holes.

40. A light-emitting diode, comprising:

a substrate having a first surface and a second surface on opposite sides;

an illuminant epitaxial structure on the first surface of the substrate, wherein the illuminant epitaxial structure comprises a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer stacked on the substrate in sequence, a stacked structure composed of the active layer and the second conductivity type semiconductor layer exposes a portion of the first conductivity type semiconductor layer, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer have different conductivity types;

an anodic oxidation metal layer deposed on the second surface of the substrate, wherein the anodic oxidation metal layer is formed from a metal layer, and the anodic oxidation metal layer includes a plurality of holes; and

a sub-mount, wherein at least two bonding bumps are set on a surface of the sub-mount, and the exposed portion of the first conductivity type semiconductor layer and the second conductivity type semiconductor layer respectively connect with the bonding bumps on the sub-mount.

41. The light-emitting diode according to claim 40, wherein a material of the metal layer is Al, Mn, Zn, Ni, Ag or Ti.

42. The light-emitting diode according to claim 40, wherein a thickness of the metal layer is between about 1 nm and about 1000 nm.

43. The light-emitting diode according to claim 40, wherein dimensions of the holes are between about 1 nm and about 1000 nm.

44. The light-emitting diode according to claim 40, wherein the holes expose a portion of the second surface of the substrate.