| 摘要 |
<p>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. A 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. <IMAGE></p> |
