Gallium nitride-based light emitting diode and fabrication method thereof

• US 7,531,827 B2
• Filed: 01/18/2006
• Issued: 05/12/2009
• 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:
  US11/333,247
• Publication Number:
  US 20060113550A1
• Time in Patent Office: 1,210 Days
• Field of Search: 257 12- 15, 257/22, 257/183, 257/189, 257/190, 257/200, 257/E25.028, 257/E25.032, 257/E33.028, 257/E33.031, 257/E33.033, 257/E33.034, 257/E33.049
• US Class Current: 257/13
• 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 buffer layer disposed above a substrate;

at least one N-type GaN layer disposed above the buffer layer;

a GaN layer having indium disposed above the N-type GaN layer;

an active layer disposed above the GaN layer having indium; and

at least one P-type GaN layer disposed above the active layer,

wherein a thickness of the GaN layer having indium is 50-200 Å

,

wherein the active layer includes a well layer, a crystal layer and a barrier layer, and

wherein the crystal layer is formed between the well layer and the barrier layer.

2. The LED according to claim 1, wherein the active layer has a three dimensional structure.

3. The LED according to claim 1, further comprising an undoped GaN layer disposed between the buffer layer and the N-type GaN layer.

4. The LED according to claim 1, wherein the GaN layer having indium has a low mole of indium.

5. The LED according to claim 1, wherein 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<

0.2.

6. The LED according to claim 1, wherein a GaN layer whose thickness is 10-30 Å

, is formed above the GaN layer having indium.

7. The LED according to claim 6, wherein the active layer directly formed on the GaN layer.

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

9. An LED comprising:

a first conductive type semiconductor layer;

a GaN layer having indium formed on the first conductive type semiconductor layer;

a GaN layer directly formed on the GaN layer having indium;

an active layer directly formed on the GaN layer; and

a second conductive type semiconductor layer disposed above the active layer,

wherein 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<

0.2,

wherein a thickness of the GaN layer having indium is 50-200 Å

,

wherein the active layer includes a well layer, a crystal layer and a barrier layer, and

wherein the crystal layer is formed between the well layer and the barrier layer.

10. The LED according to claim 9, comprising an undoped GaN layer disposed under the first conductive type semiconductor layer.

11. The LED according to claim 10, comprising a buffer layer disposed under the undoped GaN layer.

12. An LED comprising:

a first conductive type semiconductor layer;

a GaN layer having indium formed on the first conductive type semiconductor layer;

a GaN layer directly formed on the GaN layer having indium;

an active layer directly formed on the GaN layer; and

a second conductive type semiconductor layer disposed above the active layer.

13. The LED according to claim 12, wherein 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<

0.2.

14. The LED according to claim 12, wherein a thickness of the GaN layer having indium is 50-200 Å

.

15. The LED according to claim 12, a thickness of the GaN layer is 10-30 Å

.

16. The LED according to claim 12, wherein the active layer includes a well layer, a crystal layer and a barrier layer.