Light emitting diode having a first GaN layer and a first semiconductor layer each having a predetermined thickness and fabrication method therof

• US 7,884,388 B2
• Filed: 11/23/2009
• Issued: 02/08/2011
• Est. Priority Date: 07/18/2003
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Kim, Seong Jae
• Primary Examiner(s): Soward; Ida M
• Application Number:
  US12/624,404
• Publication Number:
  US 20100065816A1
• Time in Patent Office: 442 Days
• Field of Search: 257/13, 257/79, 257/94, 257 96- 97, 257101-103, 257/E33.028, 257/E33.031, 257/E33.033, 257/E33.034
• US Class Current: 257/103
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A light emitting diode (LED) and a method for fabricating the same, capable of improving brightness by forming a InGaN layer having a low concentration of indium, and whose lattice constant is similar to that of an active layer of the LED, is provided. The LED includes: a buffer layer disposed on a sapphire substrate; a GaN layer disposed on the buffer layer; a doped GaN layer disposed on the GaN layer; a GaN layer having indium disposed on the GaN layer; an active layer disposed on the GaN layer having indium; and a P-type GaN disposed on the active layer. Here, an empirical formula of the GaN layer having indium is given by In(x)Ga(1−x)N and a range of x is given by 0<x<2, and a thickness of the GaN layer having indium is 50-200 Å.

Claims

1. An LED, comprising:

a substrate;

a buffer layer on the substrate;

a first GaN layer on the buffer layer;

a first conductive type semiconductor layer on the first GaN layer;

at least one GaN layer having indium on the first conductive type semiconductor layer;

at least one second GaN layer directly on the GaN layer having indium;

an active layer directly on the second GaN layer; and

a second conductive type semiconductor layer on the active layer,

wherein a total thickness of the first GaN layer and the first conductive type semiconductor layer is 2˜

6 μ

m.

2. The LED according to claim 1, wherein an empirical formula of the GaN layer having indium is given by In_xGa_1-xN and a range of x is given by 0<

x<

0.2.

3. The LED according to claim 1, wherein the active layer is formed of a multi-quantum well structure having an InGaN/GaN structure.

4. The LED according to claim 1, wherein the buffer layer is formed of GaN-based material.

5. The LED according to claim 1, wherein a thickness of the second GaN layer is 10-30 Å

.

6. The LED according to claim 1, wherein a thickness of the first GaN layer is 1-3 μ

m.

7. The LED according to claim 1, wherein the first GaN layer includes an undoped GaN layer.

8. The LED according to claim 1, wherein a thickness of the first conductive type semiconductor layer is 1-3 μ

m.

9. The LED according to claim 1, wherein the second conductive type semiconductor layer includes at least one well layer and at least one barrier layer.

10. The LED according to claim 1, wherein the GaN layer having indium has a thickness less than 200 Å

.

11. The LED according to claim 1, wherein the second conductive type semiconductor layer has a thickness of 750-1500 Å

.

12. The LED according to claim 1, wherein the active layer includes at least one well layer and at least one barrier layer formed in 1 period to 7 periods.

13. The LED according to claim 1, the LED further comprising a transparent metal on the second conductive type semiconductor layer, wherein the transparent metal is ITO (Indium-Tin-Oxide).

14. The LED according to claim 1, the first conductive type semiconductor layer is n-type semiconductor layer and the second conductive type semiconductor layer is p-type semiconductor layer.

15. An LED, comprising:

a first conductive type semiconductor layer;

at least one GaN layer having indium on the first conductive type semiconductor layer;

at least one GaN layer directly on the GaN layer having indium;

an active layer directly on the GaN layer; and

a second conductive type semiconductor layer on the active layer, wherein the second conductive type semiconductor layer includes at least one well layer and at least one barrier layer.

16. The LED according to claim 15, wherein an empirical formula of the GaN layer having indium is given by In_xGa_1-xN and a range of x is given by 0<

x<

0.2.

17. The LED according to claim 15, wherein the active layer is formed of a multi-quantum well structure having an InGaN/GaN structure.

18. The LED according to claim 15, wherein a thickness of the GaN layer is 10-30 Å

.

19. The LED according to claim 15, wherein a thickness of the first conductive type semiconductor layer is 1-3 μ

m.

20. The LED according to claim 15, wherein the second conductive type semiconductor layer has a thickness of 750-1500 Å

.

21. The LED according to claim 15, wherein the active layer includes at least one well layer and at least one barrier layer formed in 1 period to 7 periods.

22. The LED according to claim 15, further comprising:

a substrate;

a buffer layer on the substrate; and

a first GaN layer between the buffer layer and the first conductive type semiconductor layer.

23. The LED according to claim 22, wherein a thickness of the first GaN layer is 1-3 μ

m.

24. An LED, comprising:

a first conductive type semiconductor layer;

at least one GaN layer having indium on the first conductive type semiconductor layer;

at least one GaN layer directly on the GaN layer having indium;

an active layer directly on the GaN layer; and

a second conductive type semiconductor layer on the active layer, wherein the second conductive type semiconductor layer has a thickness of 750-1500 Å

.

25. The LED according to claim 24, wherein an empirical formula of the GaN layer having indium is given by In_xGa_1-xN and a range of x is given by 0<

x<

0.2.

26. The LED according to claim 24, wherein the active layer is formed of a multi-quantum well structure having an InGaN/GaN structure.

27. The LED according to claim 24, wherein a thickness of the GaN layer is 10-30 Å

.

28. The LED according to claim 24, wherein a thickness of the first conductive type semiconductor layer is 1-3 μ

m.

29. The LED according to claim 24, wherein the active layer includes at least one well layer and at least one barrier layer formed in 1 period to 7 periods.

30. The LED according to claim 24, the LED further comprising a transparent metal on the second conductive type semiconductor layer, wherein the transparent metal is ITO (Indium-Tin-Oxide).

31. The LED according to claim 24, wherein the second conductive type semiconductor layer includes at least one well layer and at least one barrier layer.

32. The LED according to claim 24, wherein the GaN layer having indium has a thickness less than 200 Å

.

33. The LED according to claim 32, wherein the GaN layer having indium has a thickness greater than 50 Å

and less than 200 Å

.

34. The LED according to claim 24, further comprising:

a substrate;

a buffer layer on the substrate;

a first GaN layer between the buffer layer and the first conductive type semiconductor layer.

35. The LED according to claim 34, wherein the buffer layer is formed of GaN-based material.

36. The LED according to claim 34, wherein a thickness of the first GaN layer is 1-3 μ

m.

37. The LED according to claim 34, wherein a total thickness of the first GaN layer and the first conductive type semiconductor layer is 2˜

6 μ

m.

38. The LED according to claim 34, wherein the first GaN layer includes an undoped GaN layer.

39. The LED according to claim 34, wherein the buffer layer is formed of GaN-based material.

40. An LED, comprising:

a first conductive type semiconductor layer;

at least one GaN layer having indium on the first conductive type semiconductor layer, wherein the GaN layer having indium has a thickness less than 200 Å

;

at least one GaN layer directly on the GaN layer having indium;

an active layer directly on the GaN layer; and

a second conductive type semiconductor layer on the active layer.

41. The LED according to claim 40, wherein the GaN layer having indium has a thickness greater than 50 Å

and less than 200 Å

.

42. An LED, comprising:

a first conductive type semiconductor layer;

at least one GaN layer having indium on the first conductive type semiconductor layer;

at least one GaN layer directly on the GaN layer having indium, wherein the GaN layer has a thickness of 10-30 Å

;

an active layer including InGaN directly on the GaN layer, wherein the active layer includes at least one well layer and at least one barrier layer; and

a second conductive type semiconductor layer on the active layer, wherein the second conductive type semiconductor layer has a thickness of 750-1500 Å

.

43. The LED according to claim 42, wherein an empirical formula of the GaN layer having indium is given by In_xGa_1-xN and a range of x is given by 0<

x<

0.2.

44. The LED according to claim 42, wherein a thickness of the first conductive type semiconductor layer is 1-3 μ

m.

45. The LED according to claim 42, wherein the well layer and the barrier layer formed in 1 period to 7 periods.

46. The LED according to claim 42, the LED further comprising a transparent metal on the second conductive type semiconductor layer, wherein the transparent metal is ITO (Indium-Tin-Oxide).

47. The LED according to claim 42, wherein the second conductive type semiconductor layer includes at least one well layer and at least one barrier layer.

48. The LED according to claim 42, wherein the GaN layer having indium has a thickness less than 200 Å

.

49. The LED according to claim 48, wherein the GaN layer having indium has a thickness greater than 50 Å

and less than 200 Å

.

50. The LED according to claim 42, further comprising:

a first GaN layer under the first conductive type semiconductor layer.

51. The LED according to claim 50, wherein a thickness of the first GaN layer is 1-3 μ

m.

52. The LED according to claim 50, wherein a total thickness of the first GaN layer and the first conductive type semiconductor layer is 2˜

6 μ

m.

53. The LED according to claim 50, further comprising:

a buffer layer under the first GaN layer.

54. The LED according to claim 50, wherein the first GaN layer includes an undoped GaN layer.

55. The LED according to claim 54, wherein the buffer layer is formed of GaN-based material.