Gallium nitride based light emitting diode

• US 9,362,454 B2
• Filed: 11/28/2014
• Issued: 06/07/2016
• 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:
  US14/555,979
• Publication Number:
  US 20150123074A1
• Time in Patent Office: 557 Days
• US Class Current: 1/1
• 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 includes a first conductive type semiconductor layer; at least one In_xGa_1−xN layer (0<x<0.2) on the first conductive type semiconductor layer; an active layer directly on the at least one In_xGa_1−xN layer(0<x<0.2); a second conductive type semiconductor layer on the active layer; and a transparent ITO (Indium-Tin-Oxide) layer on the second conductive type semiconductor layer. At least one period of the active layer includes at least three layers including an InGaN and a GaN. The second conductive type semiconductor layer has a thickness of 750Ř1500Å.

Claims

1. A light emitting diode comprising:

an un-doped GaN layer having a thickness of 1 μ

m ˜

3 μ

m;

a first conductive type semiconductor layer on the un-doped GaN layer;

at least one In_xGa<sub>1−

x</sub>N layer (0<

x<

0.2) on the first conductive type semiconductor layer;

at least one GaN layer having a thickness of 10 Å

˜

30 Å

directly on the at least one In_xGa<sub>1−

x</sub>N layer(0<

x<

0.2);

an active layer directly on the at least one GaN layer;

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

a transparent ITO (Indium-Tin-Oxide) layer on the second conductive type semiconductor layer;

wherein the active layer comprises a well layer including an InGaN and a barrier layer including a GaN,

wherein a thickness of the barrier layer is greater than a thickness of the well layer, and

wherein a thickness of the at least one In_xGa<sub>1−

x</sub> N layer (0<

x<

0.2) is less than a thickness of the second conductive type semiconductor layer having 750 Å

˜

1500 Å

.

2. The light emitting diode according to claim 1, wherein the active layer comprises a multi-quantum well structure including at least one dopant in at least one of the well layer or the barrier layer.

3. The light emitting diode according to claim 1, wherein light generated at the active layer is emitted via the transparent ITO (Indium-Tin-Oxide) layer to an external.

4. The light emitting diode according to claim 1, wherein the at least one In_xGa₁₋

xN layer (0<

x<

0.2) is directly disposed on the first conductive type semiconductor layer.

5. The light emitting diode according to claim 1, wherein an Indium composition of the at least one In_xGa₁₋

xN layer (0<

x<

0.2) is lower than an Indium composition of the active layer.

6. The light emitting diode according to claim 1, wherein the at least one In_xGa₁₋

xN layer (0<

x<

0.2) has a thickness less than 200 Å

.

14. The light emitting diode according to claim 1, further comprising a sapphire substrate under the un-doped GaN layer.

15. The light emitting diode according to claim 1, wherein at least one period of the active layer comprises at least three layers including the InGaN and the GaN.

16. The light emitting diode according to claim 1, wherein the second conductive type semiconductor layer has a thickness of 750 Å

˜

1500 Å

.

17. The light emitting diode according to claim 1, wherein a thickness of the at least one In_xGa₁₋

xN layer (0<

x<

0.2)is less than a thickness of the second conductive type semiconductor layer.

7. A light emitting diode comprising:

an un-doped GaN layer;

a first conductive type semiconductor layer on the un-doped GaN layer;

at least one In_xGa<sub>1−

x</sub>N layer (0<

x<

0.2) on the first conductive type semiconductor layer;

at least one GaN layer directly on the at least In_XGa<sub>1−

x</sub>N layer (0<

x<

0.2);

an active layer directly on the at least one GaN layer;

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

a transparent ITO (Indium-Tin-Oxide) layer on the second conductive type semiconductor layer,

wherein the second conductive type semiconductor layer has a thickness of 750 Å

˜

1500 Å

.

8. The light emitting diode according to claim 7, wherein a thickness of the at least one GaN layer is 10 Å

˜

30 Å

.

9. The light emitting diode according to claim 7, wherein the undoped GaN layer having a thickness of 1 μ

m˜

3 μ

m.

10. The light emitting diode according to claim 7, wherein a thickness of the at least one In_xGa₁₋

xN layer (0<

x<

0.2) is less than a thickness of the second conductive type semiconductor layer.

11. The light emitting diode according to claim 7, wherein the at least one In_xGa₁₋

xN layer (0<

x<

0.2) has a thickness less than 200 Å

.

12. The light emitting diode according to claim 7, wherein the at least one In_xGa₁₋

xN layer (0<

x<

0.2) is directly disposed on the first conductive type semiconductor layer.

13. The light emitting diode according to claim 7, wherein an Indium composition of the at least one In_xGa₁₋

xN layer (0<

x<

0.2)is lower than an Indium composition of the active layer.

18. The light emitting diode according to claim 7, further comprising a substrate under the un-doped GaN layer.

19. The light emitting diode according to claim 7, wherein at least one period of the active layer comprises at least three layers including an InGaN an a GaN.

20. The light emitting diode according to claim 7, wherein the active layer comprises a multi-quantum well structure including at least one dopant in at least one of at least one well layer or at least one barrier.