Light emitting diode

• US 6,522,063 B2
• Filed: 03/28/2001
• Issued: 02/18/2003
• Est. Priority Date: 03/28/2001
• Status: Expired due to Term

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Epitech Corporation Ltd.
• Inventors: Li, Wen Liang, Chen, Henrg, Chen, Shi Ming, Wang, Hsin Chuan
• Primary Examiner(s): Martin, David
• Assistant Examiner(s): Phan, Thanh S.
• Application Number:
  US09/820,252
• Publication Number:
  US 20020158572A1
• Time in Patent Office: 692 Days
• Field of Search: 313/509, 313/506, 313/508, 313/501, 313/498, 313/499, 257/431, 257/40, 257/98, 257/89, 257/94
• US Class Current: 313/498
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• 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 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

A light emitting diode. The light emitting diode has a substrate that has two surfaces. On one surface, a distributed Bragg reflector, an n-type confining layer, an active layer, a p-type confining layer, a current spreading layer, a meshed Ohmic contact layer, a transparent conductive oxide layer and a front side electrode are formed. The other surface has a rear side electrode formed thereon. Via the meshed structure, the absorbing area of the Ohmic contact layer is reduced to avoid the light emitting from the active layer being greatly absorbed by the Ohmic contact layer. In contrast, the light intensity of the light emitting diode is increased.

Claims

1. A light emitting diode, comprising:

a substrate having a first side and a second side;

an electrode, on the second side of the substrate;

a distributed Bragg reflector, on the first side of the substrate;

a first conductive type confining layer, on the distributed Bragg reflector;

an active layer, on the first conductive type confining layer;

a second conductive type confining layer, on the active layer;

a current spreading layer, on the second conductive type confining layer;

a meshed Ohmic contact layer, on the current spreading layer;

a transparent conductive oxide layer, on the meshed Ohmic contact layer; and

a front side electrode, on a portion of the transparent conductive oxide layer.

2. The light emitting diode according to claim 1, wherein the first conductive type confining layer includes an n-type aluminum indium gallium phosphide layer.

3. The light emitting diode according to claim 1, wherein the second conductive type confining layer includes a p-type aluminum indium gallium phosphide layer.

4. The light emitting diode according to claim 1, wherein the material of the active layer is selected from an undoped aluminum indium gallium phosphide with a quantum well structure.

5. The light emitting diode according to claim 1, wherein the material of the current spreading layer includes a group consisting of aluminum gallium arsenide and gallium phosphide.

6. The light emitting diode according to claim 1, wherein the material of the meshed Ohmic contact layer includes a group consisting of gallium arsenide, gallium phosphide and gallium phosphide arsenide.

7. The light emitting diode according to claim 1, wherein the material of the transparent conductive oxide layer is selected from a group consisting of indium oxide, tin oxide and indium tin oxide.

8. A light emitting diode, comprising:

a substrate having a first side and a second side;

an electrode, on the second side of the substrate;

a distributed Bragg reflector, on the first side of the substrate;

a first conductive type confining layer, on the distributed Bragg reflector;

an active layer, on the first conductive type confining layer;

a second conductive type confining layer, on the active layer;

a meshed Ohmic contact layer, on the second conductive type confining layer;

a transparent conductive oxide layer, on the meshed Ohmic contact layer; and

a front side electrode, on the transparent conductive oxide layer.

9. The light emitting diode according to claim 8, wherein the first conductive type confining layer includes an n-type aluminum indium gallium phosphide layer.

10. The light emitting diode according to claim 8, wherein the second conductive type confining layer includes a p-type aluminum indium gallium phosphide layer.

11. The light emitting diode according to claim 8, wherein the material of the active layer is selected from an undoped aluminum indium gallium phosphide with a quantum well structure.

12. The light emitting diode according to claim 8, wherein the material of the meshed Ohmic contact layer includes a group consisting of gallium arsenide, gallium phosphide and gallium phosphide arsenide.

13. The light emitting diode according to claim 8, wherein the material of the transparent conductive oxide layer is selected from a group consisting of indium oxide, tin oxide and indium tin oxide.

14. A light emitting diode, comprising:

a substrate having a first side and a second side;

an electrode, on the second side of the substrate;

a distributed Bragg reflector, on the first side of the substrate;

a first conductive type confining layer, on the distributed Bragg reflector;

an active layer, on the first conductive type confining layer;

a second conductive type confining layer, on the active layer;

a current spreading layer, on the second conductive confining layer;

a meshed Ohmic contact layer, on the current spreading layer, wherein the meshed Ohmic contact layer has a first thickness and a plurality of gridlines of a first width, the gridlines spaced with-from each other by a second width;

a transparent conductive oxide layer, on the meshed Ohmic contact layer; and

a front side electrode, on the transparent conductive oxide layer.

15. The light emitting diode according to claim 14, wherein the first conductive type confining layer includes an n-type aluminum indium gallium phosphide layer.

16. The light emitting diode according to claim 14, wherein the second conductive type confining layer includes a p-type aluminum indium gallium phosphide layer.

17. The light emitting diode according to claim 14, wherein the active layer is made of a material selected from a group consisting of an undoped aluminum indium gallium phosphide and a quantum well structure thereof.

18. The light emitting diode according to claim 14, wherein the material of the current spreading layer is selected from a group consisting of aluminum gallium arsenide and gallium phosphide.

19. The light emitting diode according to claim 14, wherein the material of the meshed Ohmic contact layer is selected from a group consisting of gallium arsenide, gallium phosphide and gallium arsenic phosphide.

20. The light emitting diode according to claim 14, wherein the first thickness is about 6 microns.

21. The light emitting diode according to claim 14, wherein the first width is about 5 microns.

22. The light emitting diode according to claim 14, wherein the second width is about 1 micron.

23. The light emitting diode according to claim 14, wherein the material of the transparent conductive oxide layer is selected from a group consisting of indium oxide, tin oxide and indium tin oxide.