High brightness light emitting diode

• US 6,806,112 B1
• Filed: 09/22/2003
• Issued: 10/19/2004
• Est. Priority Date: 09/22/2003
• Status: Active Grant

• Current Assignee: National Science Council
• Original Assignee: National Chung Hsing University (Government of The Republic of China)
• Inventors: Horng, Ray-Hua, Chiu, Chi-Ying, Wu, Dong-Sing, Chiang, Yann-Jyh
• Primary Examiner(s): Fourson, George
• Assistant Examiner(s): Maldonado, Julio J.
• Application Number:
  US10/668,554
• Time in Patent Office: 393 Days
• Field of Search: 438/33, 438/29, 438/39, 438/42, 438/458, 438/956, 257/E33.068
• US Class Current: 438/29
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate

Abstract

The present invention discloses a high brightness light emitting diode and a method for producing the same. The light emitting diode includes a gallium phosphide window and a reflective mirror so as to promote brightness thereof. To produce the light emitting diode, a glass substrate is bonded to the main structure of the light emitting diode and then the temporary substrate for epitaxing thereon can be removed for depositing a reflective mirror. After bonding a permanent substrate below the reflective mirror, the glass substrate is removed, too. By means of the double-bonding process, reflectivity of the mirror is maintained in the present invention.

Claims

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

a) providing a temporary substrate for epitaxing;

b) sequentially epitaxing an n-type cladding layer, an active layer with quantum well structure and a p-type cladding layer on said temporary substrate;

c) forming a p-GaP layer on said p-type cladding layer;

d) forming a metal contact layer on said p-GaP layer;

e) etching a part of said metal contact layer, said p-GaP layer, said p-type cladding layer and said active layer, and an upper part of said n-type cladding layer to expose said n-type cladding layer;

f) forming a p-type ohmic contact electrode and an n-type ohmic contact electrode on said metal contact layer and said exposed n-type cladding layer to complete a main structure of said light emitting diode;

g) bonding a glass substrate to an surface of said main structure on which with said electrodes are present;

h) removing said temporary substrate;

i) forming a reflective mirror on a bottom surface of said n-type cladding layer;

j) bonding a permanent substrate to a bottom surface of said reflective mirror; and

k) removing said glass substrate.

2. The method as claimed in claim 1, wherein said temporary substrate is a GaAs substrate.

3. The method as claimed in claim 1, wherein said active layer is made from AlGaInP.

4. The method as claimed in claim 1, wherein said reflective mirror is selected from the group consisting of In, Sn, Al, Au, Pt, Pd, Zn, Ag, Ge, Ni, Au/Zn, Au/Be, Au/Ge and Au/Ge/Ni, or mixtures thereof.

5. The method as claimed in claim 1, wherein said reflective mirror is a composite of high dielectric and low dielectric.

6. The method as claimed in claim 1, wherein said reflective mirror is a composite of dielectric and metal.

7. The method as claimed in claim 1, wherein said permanent substrate is bonded to the bottom surface of said reflective mirror by being previously coated an adhesive layer at a temperature below 350°

C.

8. The method as claimed in claim 7, wherein said adhesive layer is a pure metal or an alloy with a melting point less than 350°

C.

9. The method as claimed in claim 1, which further comprises a transparent conductive film between said metal contact layer and said p-type ohmic contact electrode.

10. The method as claimed in claim 1, wherein said p-type ohmic contact electrode is a transparent conductive film.