Nitride semiconductor LED and fabrication method thereof

• US 8,089,082 B2
• Filed: 11/01/2010
• Issued: 01/03/2012
• Est. Priority Date: 07/06/2005
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Lee, Suk Hun
• Primary Examiner(s): Tran, Long
• Assistant Examiner(s): KLEIN, JORDAN M
• Application Number:
  US12/917,082
• Publication Number:
  US 20110042645A1
• Time in Patent Office: 428 Days
• Field of Search: 257/95, 257/96, 257/97, 257/E33.027, 257/E33.008, 257/E33.001
• US Class Current: 257/96
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• 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 33/14 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 33/36 characterised by the electrodes

Abstract

A nitride semiconductor light emitting diode according to the present invention, includes: a substrate; a buffer layer formed on the substrate; an In-doped GaN layer formed on the buffer layer; a first electrode layer formed on the In-doped GaN layer; an In_xGa_1−xN layer formed on the first electrode layer; an active layer formed on the In_xGa_1−xN layer; a first P—GaN layer formed on the active layer; a second electrode layer formed on the first P—GaN layer; a second P—GaN layer partially protruded on the second electrode layer; and a third electrode formed on the second P—GaN layer.

Claims

1. A light emitting diode, comprising:

a first conductive semiconductor layer;

an active layer on the first conductive semiconductor layer;

a second conductive semiconductor layer on the active layer;

a third conductive semiconductor layer on the second conductive semiconductor layer;

a fourth semiconductor layer on the third conductive semiconductor layer, and

a fifth semiconductor layer formed on a surface of the fourth semiconductor layer,

wherein the fourth semiconductor layer comprises portions partially protruded from the third conductive semiconductor layer and the portions are spaced apart from each other,

wherein the fourth semiconductor layer includes a dopant of an opposite polarity from a polarity of the first conductive semiconductor layer,

wherein the first conductive semiconductor layer, the third conductive semiconductor layer and the fifth semiconductor layer comprise an n-type semiconductor layer,

wherein the second conductive semiconductor layer and the fourth semiconductor layer comprise a p-type semiconductor layer.

2. The light emitting diode according to claim 1, wherein a width of a top surface of the fourth semiconductor layer is smaller than a width of lower surface of the fourth semiconductor layer.

3. The light emitting diode according to claim 1, wherein the fifth semiconductor layer comprises segments spaced apart from each other and the fourth semiconductor layer has a protrusive convex shape, respectively.

4. The light emitting diode according to claim 1, wherein a thickness of the fourth semiconductor layer is thicker than a thickness of the fifth semiconductor layer.

5. The light emitting diode according to claim 1, wherein the active layer includes a well layer, a GaN based cap layer and a barrier layer and has a single quantum well structure or a multi quantum well structure.

6. A light emitting diode, comprising:

a first conductive semiconductor layer;

an active layer on the first conductive semiconductor layer;

a second conductive semiconductor layer on the active layer;

a third conductive semiconductor layer on the second conductive semiconductor layer;

a fourth semiconductor layer on the third conductive semiconductor layer; and

a fifth semiconductor layer formed on a surface of the fourth semiconductor layer,

wherein the third conductive semiconductor layer and the second conductive semiconductor layer have substantially the same width,

wherein the fourth semiconductor layer comprises portions partially protruded from the third conductive semiconductor layer and the portions are spaced apart from each other,

wherein the fourth semiconductor layer includes a dopant of an opposite polarity from a polarity of the first conductive semiconductor layer,

wherein the first conductive semiconductor layer, the third conductive semiconductor layer and the fifth semiconductor layer comprise an n-type semiconductor layer,

wherein the second conductive semiconductor layer and the fourth semiconductor layer comprise a p-type semiconductor layer.

7. The light emitting diode according to claim 6, wherein the third conductive semiconductor layer is an n-In_xGa₁₋

xN based layer, wherein an indium content of the third conductive semiconductor layer is sequentially fluctuated.

8. The light emitting diode according to claim 7, wherein the n-In_xGa₁₋

xN based layer has a range of 0<

x<

0.2.

9. The light emitting diode according to claim 6, wherein the first conductive semiconductor layer is a GaN based layer.

10. The light emitting diode according to claim 6, further comprising an In_xGa₁₋

xN based layer between the first conductive semiconductor and the active layer.

11. The light emitting diode according to claim 6, further comprising an electrode formed on the fourth semiconductor layer and the third conductive semiconductor layer,

wherein the electrode is formed of transmission metal oxide or transmission resistant metal.

12. The light emitting diode according to claim 11, wherein the transmission metal oxide is a selected one of Indium-Tin-Oxide (ITO), Zinc Oxide (ZnO), iridium oxide (IrOx), ruthenium oxide (RuOx), and nickel oxide (NiO).

13. The light emitting diode according to claim 11, wherein the transmission resistant metal is aurum (Au) alloy containing nickel (Ni).

14. A light emitting diode, comprising:

a first conductive semiconductor layer;

an active layer on the first conductive semiconductor layer;

a second conductive semiconductor layer on the active layer;

a third conductive semiconductor layer on the second conductive semiconductor layer;

a fourth semiconductor layer on the third conductive semiconductor layer; and

a fifth semiconductor layer formed on a surface of the fourth semiconductor layer,

wherein the third conductive semiconductor layer and the second conductive semiconductor layer have substantially the same width,

wherein the fourth semiconductor layer comprises portions partially protruded from the third conductive semiconductor layer and the portions are spaced apart from each other,

wherein the fourth semiconductor layer includes a dopant of an opposite polarity from a polarity of the first conductive semiconductor layer,

wherein the fifth semiconductor layer includes a super lattice structure of a InGaN based layer/InGaN based layer on the fourth semiconductor layer portions spaced apart from each other.

15. The light emitting diode according to claim 14, wherein the third conductive semiconductor layer has an opposite polarity from a polarity of the second conductive semiconductor layer.

16. The light emitting diode according to claim 14, wherein the first conductive semiconductor layer, the third conductive semiconductor layer and the fifth semiconductor layer comprise an n-type semiconductor layer,

wherein the second conductive semiconductor layer and the fourth semiconductor layer comprise a p-type semiconductor layer.