| US 7,550,786 B2 | ||
| Compound semiconductor epitaxial substrate | ||
| Hisashi Yamada, Tsukuba (Japan); Takenori Osada, Chiba (Japan); and Noboru Fukuhara, Tsukuba (Japan) | ||
| Assigned to Sumitomo Chemical Company, Limited, Tokyo (Japan); and Sumika Epi Solution Company, Ltd., Tokyo (Japan) | ||
| Appl. No. 10/554,706 PCT Filed Apr. 07, 2004, PCT No. PCT/JP2004/005016 § 371(c)(1), (2), (4) Date Oct. 27, 2005, PCT Pub. No. WO2004/097924, PCT Pub. Date Nov. 11, 2004. |
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| Claims priority of application No. 2003-124374 (JP), filed on Apr. 28, 2003. | ||
| Prior Publication US 2006/0255367 A1, Nov. 16, 2006 | ||
| Int. Cl. H01L 29/739 (2006.01); H01L 31/072 (2006.01) | ||
| U.S. Cl. 257—197 [257/190; 257/198] | 4 Claims |
| 1. A compound semiconductor epitaxial substrate comprising a substrate, and a sub-collector layer, a collector layer, a base
layer, an emitter layer and a contact layer(s) formed in this order on said substrate,
wherein said compound semiconductor epitaxial substrate has an oxygen-containing layer between said substrate and said sub-collector
layer, and said oxygen-containing layer has an oxygen concentration of 1×1016 cm−3 or more and 1×1021 cm −3 or less.
|