| 摘要 |
An N type buried layer is buried in a P type silicon substrate. An N type epitaxial layer is formed on this buried layer. A P type intrinsic base region and an extrinsic base region are formed on the surface of the epitaxial layer. An N type emitter region is formed in the intrinsic base region. An emitter electrode is formed to contact the emitter region. A collector plug region is formed in an area separated from the extrinsic base region through a filed insulating film. A cobalt silicide film is formed on the extrinsic base region to surround the emitter electrode. An extrinsic base contact hole is formed at only one side of the emitter electrode. In the semiconductor device, the base resistance Rb and the collector-base capacity Ccb are reduced to make the maximum oscillation frequency fmax sufficiently large.
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