LIGHT EMITTING DIODE HAVING AN OMNIDIRECTIONAL REFLECTOR INCLUDING A TRANSPARENT CONDUCTIVE LAYER

• US 20060006402A1
• Filed: 07/08/2005
• Published: 01/12/2006
• Est. Priority Date: 07/12/2004
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Hsieh, Min-Hsun, Tseng, Tzu-Feng, Tao, Ching-San, Ni, Jr-Peng
• Granted Patent: US 7,326,967 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

The present invention is related to a light emitting diode of an omnidirectional reflector providing with a transparent conductive layer. In the present invention, a cohesion layer is formed between a transparent layer and a metal reflection layer to improve the cohesive force therebetween and increase the reflectivity of the light emitting diode, so as the present invention can enhance the light-emitting efficiency of the light emitting diode.

Claims

1. An omnidirectional reflector comprising:

a transparent conductive layer;

a metal reflection layer; and

a cohesion layer between the transparent conductive layer and the metal reflection layer.

2. The omnidirectional reflector of claim 1, wherein the transparent conductive layer is made of at least one material selected from the group consisting of Tin Indium Oxide, Tin Cadmium Oxide, Tin Antimony Oxide, Zinc Oxide, and Tin Zinc Oxide.

3. The omnidirectional reflector of claim 1, wherein the cohesion layer is made of at least one material selected from the group consisting of SiNx, SiO₂, SiO, TiO₂, Al₂O₃, and the like.

4. The omnidirectional reflector claims 1, wherein the metal reflection layer is made of at least one material selected from the group consisting of Al and Ag.

5. A light-emitting diode having an omnidirectional reflector, comprising:

a substrate;

a metal reflection layer;

a cohesion layer formed on the metal reflection layer;

a transparent conductive layer formed on the cohesion layer;

an LED stack formed on the transparent conductive layer; and

an adhesive layer formed between the substrate and metal reflection layer.

6. The light-emitting diode of claim 5 further comprising:

a reaction layer formed between the substrate and the adhesive layer or between the adhesive layer and the metal reflection layer.

7. The light-emitting diode of claim 6 wherein the reaction layer is made of at least one material selected from the group consisting of SiNx, Ti, and Cr.

8. The light-emitting diode of claim 5 further comprising:

a first reaction layer formed between the substrate and the adhesive layer and a second reaction layer formed between the adhesive layer and the metal reflection layer.

9. The light-emitting diode of claim 8, wherein the first or second reaction layer is made of at least one material selected from the group consisting of SiNx, Ti, and Cr.

10. The light-emitting diode of claim 5 further comprising:

a transparent conductive layer formed on the LED stack.

11. The light-emitting diode of claim 10, wherein the transparent conductive layer is made of at least one material selected from the group consisting of Tin Indium Oxide, Tin Cadmium Oxide, Tin Antimony Oxide, Zinc Oxide, and Tin Zinc Oxide.

12. The light-emitting diode of claim 5, wherein the transparent conductive layer is made of at least one material selected from the group consisting of s Tin Indium Oxide, Tin Cadmium Oxide, Tin Antimony Oxide, Zinc Oxide, and Tin Zinc Oxide.

13. The light-emitting diode of claim 5, wherein the cohesion layer is made of at least one material selected from the group consisting of SiNx, SiO₂, SiO, TiO₂, Al₂O₃, and the like.

14. The light-emitting diode of claim 5, wherein the metal reflection layer is made of at least one material selected from the group consisting of Al and Ag.

15. The light-emitting diode of claim 5, wherein the substrate is made of at least one material selected from the group consisting of GaAs, AlGaAs, GaAsP, GaP, Si, SiC, metals, sapphire, GaN, AlN, ZnO, MgO, glass, and the like.

16. The light-emitting diode of claim 5, wherein the adhesive layer is made of at least one material selected from the group consisting of Pi, BCB, PFCB, and the like.

17. The light-emitting diode of claim 5, wherein the LED stack comprises:

a first contact layer;

a first cladding layer formed on the first contact layer;

a light-emitting layer formed on the first cladding layer;

a second cladding layer formed on the light-emitting layer; and

a second contact layer formed on the second cladding layer.

18. The light-emitting diode of claim 17, wherein the first contact layer is made of at least one material selected from the group consisting of GaP, GaAs, GaAsP, AlGaInP, GaN, InGaN, and AlGaN.

19. The light-emitting diode of claim 17, wherein the first cladding layer is made of at least one material selected from the group consisting of AlGaInP, AlInP, AlN, GaN, AlGaN, InGaN, and AlGaInN.

20. The light-emitting diode of claim 17, wherein the light-emitting layer is made of at least one material selected from the group consisting of AlGalnP, InGaP, GaN, AlGaN, InGaN, and AlGaInN.

21. The light-emitting diode of claim 17, wherein the second cladding layer is made of at least one material selected from the group consisting of AlGalnP, AlInP, AlN, GaN, AlGaN, InGaN, and AlGaInN.

22. The light-emitting diode of claim 17, wherein the second contact layer is made of at least one material selected from the group consisting of GaP, GaAs, GaAsP, InGaP, AlGaInP, AlGaAs, GaN, InGaN, and AlGaN.

23. A flip-chip light-emitting diode having an omnidirectional reflector providing, comprising:

a transparent substrate optionally including an adhesive layer;

an LED stack formed below the transparent substrate;

a transparent conductive layer formed below the LED stack;

a cohesion layer having a distributed geometrical pattern thereon and formed below the transparent conductive layer; and

a metal reflection layer formed below the cohesion layer.

24. The light-emitting diode of claim 23, wherein the transparent conductive layer is made of at least one material selected from the group consisting of s Tin Indium Oxide, Tin Cadmium Oxide, Tin Antimony Oxide, Zinc Oxide, and Tin Zinc Oxide.

25. The light-emitting diode of claim 23, wherein the cohesion layer is made of at least one material selected from the group consisting of SiNx, SiO₂, SiO, TiO₂, Al₂O₃ and the like.

26. The light-emitting diode of claim 23, wherein the metal reflection layer is made of at least one material selected from the group consisting of Al and Ag.

27. The light-emitting diode of claim 23, wherein the transparent substrate is made of at least one material selected from the group consisting of GaP, SiC, sapphire, GaN, ZnO, MgO, and the like.

28. The light-emitting diode of claim 23, wherein the adhesive layer is made of at least one material selected from the group consisting of Pi, BCB, PFCB, and the like.

29. The light-emitting diode of claim 23, wherein the LED stack comprises:

a first contact layer;

a first cladding layer formed on the first contact layer;

a light-emitting layer formed on the first cladding layer;

a second cladding layer formed on the light-emitting layer; and

a second contact layer formed on the second cladding layer.

30. The light-emitting diode of claim 29, wherein the first contact layer is made of at least one material selected from the group consisting of GaP, GaAs, GaAsP, AlGaInP, GaN, InGaN, and AlGaN.

31. The light-emitting diode of claim 29, wherein the first cladding layer is made of at least one material selected from the group consisting of AlGaInP, AlInP, AlN, GaN, AlGaN, InGaN, and AlGaInN.

32. The light-emitting diode of claim 29, wherein the light-emitting layer is made of at least one material selected from the group consisting of AlGalnP, InGaP, GaN, AlGaN, InGaN, and AlGaInN.

33. The light-emitting diode of claim 29, wherein the second cladding layer is made of at least one material selected from the group consisting of AlGalnP, AlInP, AlN, GaN, AlGaN, InGaN, and AlGaInN.

34. The light-emitting diode of claim 29, wherein the second contact layer is made of at least one material selected from the group consisting of GaP, GaAs, GaAsP, InGaP, AlGaInP, AlGaAs, GaN, InGaN, and AlGaN.