Changhua Chen from San Ramon, CA, age 44

Epitaxial Material Grown Laterally Within A Trench And Method For Producing Same
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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.

Formation Of Ohmic Contacts In Iii-Nitride Light Emitting Devices
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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.

Formation Of Ohmic Contacts In Iii-Nitride Light Emitting Devices
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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.

Formation Of Ohmic Contacts In Iii-Nitride Light Emitting Devices
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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.