Changhua Chen

US Patent:

6500257, Dec 31, 2002

Filed:

Apr 17, 1998

Appl. No.:

09/062028

Inventors:

Shih-Yuan Wang - Palo Alto CA
Changhua Chen - San Jose CA
Yong Chen - Mountain View CA
Scott W. Corzine - Sunnyvale CA
R. Scott Kern - San Jose CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

C30B 2300

US Classification:

117 95, 438479

Abstract:

An epitaxial material grown laterally in a trench allows for the fabrication of a trench-based semiconductor material that is substantially low in dislocation density. Initiating the growth from a sidewall of a trench minimizes the density of dislocations present in the lattice growth template, which minimizes the dislocation density in the regrown material. Also, by allowing the regrowth to fill and overflow the trench, the low dislocation density material can cover the entire surface of the substrate upon which the low dislocation density material is grown. Furthermore, with successive iterations of the trench growth procedure, higher quality material can be obtained. Devices that require a stable, high quality epitaxial material can then be fabricated from the low dislocation density material.

US Patent:

6630695, Oct 7, 2003

Filed:

Jul 8, 2002

Appl. No.:

10/191886

Inventors:

Changhua Chen - San Jose CA 95129
James Dong - Claremont CA 91711
Heng Liu - Arcadia CA 91007

International Classification:

H01L 3300

US Classification:

257190, 257103

Abstract:

A GaN based three layer buffer structure disposed on a substrate, and having a GaN layer disposed on the three layer buffer structure, the GaN layer serving as a platform for growth of a light emitting structure thereon.

US Patent:

6794731, Sep 21, 2004

Filed:

Oct 9, 1998

Appl. No.:

09/169218

Inventors:

Stephen A. Stockman - San Jose CA
Daniel A. Steigerwald - Cupertino CA
Changhua Chen - San Jose CA

Assignee:

Lumileds Lighting U.S., LLC - San Jose CA

International Classification:

H01L 29167

US Classification:

257610, 257 13, 257 79, 257 80, 257 82, 257103, 257918

Abstract:

A method for improving the operating stability of compound semiconductor minority carrier devices and the devices created using this method are described. The method describes intentional introduction of impurities into the layers adjacent to the active region, which impurities act as a barrier to the degradation process, particularly undesired defect formation and propagation. A preferred embodiment of the present invention uses O doping of III-V optoelectronic devices during an epitaxial growth process to improve the operating reliability of the devices.

US Patent:

6888171, May 3, 2005

Filed:

Dec 22, 2000

Appl. No.:

09/748801

Inventors:

Heng Liu - Los Angeles CA, US
Changhua Chen - Los Angeles CA, US

Assignee:

Dallan Luming Science & Technology Group Co., Ltd. - Dalian

International Classification:

H01L027/15
H01L029/12
H01L029/40

US Classification:

257 99, 257 79, 257613, 257615, 257612, 257624, 257626

Abstract:

A semi-conductor light emitting diode includes closely spaced n and p electrodes formed on the same side of a substrate to form an LED with a small foot-print. A semi-transparent U shaped p contact layer is formed along three sides of the top surface of the underlying window layer. The p electrode is formed on the p contact layer centered on the closed end of the U shaped layer. An n contact layer is formed on an n cladding layer and centered in the open end of the U of the p contact layer. The n electrode is formed on the n contact layer. The n and p electrodes are electrically isolated from one another by either a trench or an insulator, situated between the electrodes.

US Patent:

6914272, Jul 5, 2005

Filed:

Nov 24, 2003

Appl. No.:

10/721440

Inventors:

Werner K. Goetz - Palo Alto CA, US
Michael D. Camras - Sunnyvale CA, US
Changhua Chen - San Jose CA, US
Gina L. Christenson - Sunnyvale CA, US
R. Scott Kern - San Jose CA, US
Chihping Kuo - Milpitas CA, US
Paul Scott Martin - Pleasanton CA, US
Daniel A. Steigerwald - Cupertino CA, US

Assignee:

Lumileds Lighting U.S., LLC - San Jose CA

International Classification:

H01L033/00

US Classification:

257123, 257 79, 257 86, 257102, 257103, 313506

Abstract:

P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 Ωcm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.

US Patent:

20020008243, Jan 24, 2002

Filed:

Jan 5, 2001

Appl. No.:

09/755935

Inventors:

Werner Goetz - Palo Alto CA, US
Michael Camras - Sunnyvale CA, US
Changhua Chen - San Jose CA, US
Xiaoping Chen - San Jose CA, US
Gina Christenson - Sunnyvale CA, US
R. Kern - San Jose CA, US
Chihping Kuo - Milpitas CA, US
Paul Martin - Pleasanton CA, US
Daniel Steigerwald - Cupertino CA, US

International Classification:

H01L027/15

US Classification:

257/079000

Abstract:

P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 cm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.

US Patent:

20050167693, Aug 4, 2005

Filed:

Mar 30, 2005

Appl. No.:

11/095854

Inventors:

Werner Goetz - Palo Alto CA, US
Michael Camras - Sunnyvale CA, US
Changhua Chen - San Jose CA, US
Xiaoping Chen - San Jose CA, US
Gina Christenson - Sunnyvale CA, US
R. Kern - San Jose CA, US
Chihping Kuo - Milpitas CA, US
Paul Martin - Pleasanton CA, US
Daniel Steigerwald - Cupertino CA, US

International Classification:

H01L021/00
H01L033/00

US Classification:

257103000, 438022000

Abstract:

P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 Ω cm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.

US Patent:

59090510, Jun 1, 1999

Filed:

Feb 18, 1997

Appl. No.:

8/802183

Inventors:

Stephen A. Stockman - San Jose CA
Daniel A. Steigerwald - Cupertino CA
Changhua Chen - San Jose CA

Assignee:

Hewlett-Packard Company - Palo alto CA

International Classification:

H01L 3300
H01L 29167

US Classification:

257610

Abstract:

A method for improving the operating stability of compound semiconductor minority carrier devices and the devices created using this method are described. The method describes intentional introduction of impurities into the layers adjacent to the active region, which impurities act as a barrier to the degradation process, particularly undesired defect formation and propagation. A preferred embodiment of the present invention uses O doping of III-V optoelectronic devices during an epitaxial growth process to improve the operating reliability of the devices.