| 摘要 |
PURPOSE:To isolate a collector completely from a substrate, by using the collector and an emitter formable by the same process so as to compose a longitudinal type bipolar transistor. CONSTITUTION:After a p-type diffusion layer 4 is used to obtain isolation regions for NPN and PNP transistors and a CMOSFET, p-type impurities are used to perform ion implantation or the like so as to form a (p) well layer 5 and a collector layer 51 into said two transistors by the same process, n type impurities are used to form a base layer 61 and an (n) well layer 6 in the same process in the collector layer 51 and the (P) channel FET part. After the formation of the base layer 71, a P channel FET p<+> S/D diffusion layer 9 and an N channel FET n<+> S/D diffusion layer 84 are formed in the CMOS part. An emitter layer 91 is formed in the base layer 61 at the bipolar part by the same process as the p<+> S/D diffusion layer 9 is formed, and an emitter layer 81, a collector layer 82 are formed in the base layer 71 by the same process as the n<+> S/D diffusion layer 84 is formed. Hence, a circuit high in its collector potential can be used without necessitating the formation of the collector common to ground.
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