Method for producing high-brightness LED

• US 20030087463A1
• Filed: 09/30/2002
• Published: 05/08/2003
• Est. Priority Date: 11/07/2001
• Status: Abandoned Application

• Current Assignee: National Chung Hsing University (Government of The Republic of China)
• Original Assignee: National Chung Hsing University (Government of The Republic of China)
• Inventors: Chung, Chih-Ru, Horng, Ray-Hua, Wu, Tung-Hsing, Huang, Shao-Hua, Yang, Juin-Jer
• Application Number:
  US10/256,713
• Publication Number:
  US 20030087463A1
• Time in Patent Office: Days
• US Class Current: 438/29
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

The present invention discloses a method for producing a high-brightness light emitting diode (LED), which primarily includes at least one step of bonding a reflective layer formed on an LED epitaxial layer to an adhesive layer formed on an Si substrate. An n-type ohmic contact electrode and a p-type ohmic contact electrode are deposed on the front side of the LED. In the present invention, the reflective layer, the adhesive layer and the ohmic contact electrodes preferably perform single function, so that the most appropriate materials can be applied. Therefore, the LED of the present invention can exhibit excellent brightness.

Claims

1. A method for producing a high-brightness light emitting diode, comprising steps of:

A) forming a reflective layer on an LED epitaxial layer and a first adhesive layer on an Si substrate, wherein said LED epitaxial layer is grown on a temporary substrate and has a pn junction structure to define a first-type layer adjacent to said temporary substrate and a second-type layer;

B) bonding said reflective layer to said first adhesive layer by thermal pressing and then removing said temporary substrate;

C) forming a first-type ohmic contact electrode on partial top surface of said LED eptaxitial layer by physical vapor deposition;

D) etching at least partial remained LED epitaxial layer from top surface thereof and stopping at said second-type layer to form a metal contact layer; and

E) forming a second-type ohmic contact electrode on said metal contact layer by physical vapor deposition.

2. The method as claimed in claim 1, wherein said LED eptaxitial layer further comprises a p-type confining layer and a n-type confining layer.

3. The method as claimed in claim 1, wherein said first ohmic contact electrode further comprises a transparent electrode thereon.

4. The method as claimed in claim 1, wherein said reflective layer comprises a metal and an insulator.

5. The method as claimed in claim 4, wherein said insulator is adjacent to said LED epitaxial layer.

6. The method as claimed in claim 4, wherein said metal is selected from the group consisting of Al, Ag, Au, Pt, Pd.

7. The method as claimed in claim 4, wherein said insulator is selected from the group consisting of Al₂O₃, MgF₂, SiO₂, TiO₂ and Si₃N₄.

8. The method as claimed in claim 1, wherein said reflective layer comprises a high-dielectric material and a low-dielectric material.

9. The method as claimed in claim 8, wherein said low-dielectric material is adjacent to said LED epitaxial layer.

10. The method as claimed in claim 8, wherein said high-dielectric material has a refractive index larger than 2.1, and said low-dielectric material has a refractive index less than 1.56.

11. The method as claimed in claim 8, wherein said high-dielectric material is selected from the group consisting of TiO₂, CeO₂, and Si.

12. The method as claimed in claim 8, wherein said low-dielectric material is selected from the group consisting of Al₂O₃, MgF₂, SiO₂ and Si₃N₄.

13. The method as claimed in claim 1, wherein said etching of step D) is chemical wet etching or dry etching.

14. The method as claimed in claim 1, wherein said physical vapor deposition of steps C) and E) is e-gun evaporation deposition.

15. The method as claimed in claim 1, wherein said physical vapor deposition of steps C) and E) is thermal evaporation deposition.

16. The method as claimed in claim 1, wherein said physical vapor deposition of steps C) and E) is sputter deposition.

17. The method as claimed in claim 1, wherein said reflective layer further comprises a second adhesive layer therebelow to reinforce attachment with said first adhesive layer.

18. The method as claimed in claim 17, wherein said second adhesive layer is a metal.

19. The method as claimed in claim 1, wherein said first adhesive layer is a metal.

20. The method as claimed in claim 1, wherein said first adhesive layer is a polymer nonconductor.