| 摘要 |
PURPOSE:To improve the high frequency characteristics of a semiconductor device of a bipolar transistor by retaining an insulating film at an infinitesimal distance on the boundary between the emitter and the base, thereby reducing the base resistance and the capacity between the base and the emitter. CONSTITUTION:This semiconductor device has a p type semiconductor substrate 1, an n<+> type buried layer 2, an n type epitaxial layer 3, a p type isolation diffused region 4, a collector contact diffused part 5, a base layer 6 and an emitter 8, and an insulating film 8 of approx. 3000Angstrom thick for contacting hole is retained on the surface on the boundary between the emitter and the base at the infinitesimal distance 8' of approx. 2mum. Further, conductive polysilicons 9, 9' are formed. |
