| 摘要 |
PURPOSE:To reduce the parasitic capacitance in a base, in a bipolar transistor, by arranging an emitter and a base taking-out electrode only through an SiO2 film, thereby reducing carriers between the emitter and a base or between a collector and the base, and reducing a base area. CONSTITUTION:On a P-type silicon substrate 11, an N<+> type embedded layer 12 is formed. An N-type epitaxial layer 13 is formed by epitaxial growing on the layer 12. A base region 15 is formed in active region, which is confined by a field oxide film for element isolation. On a base region, a P<+> type doped polysilicon film 16, which is to become a base taking-out electrode, is arranged. A hole is opened in the polysilicon film 16 for an emitter forming part. An SiO2 film 17, which is to become an insulating film, is formed on the surface. The polysilicon film, which is to become the base taking-out electrode, is all contacted with the base region 15, except the thickness of the SiO2 film 17 and a part where the SiC film 18 is contacted with the substrate. Therefore even if the base region 15 is formed in a small shape, the base resistance can be suppressed to a small value, and the parasitic capacitance of the base can be made small.
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