| 摘要 |
PURPOSE:To realize a highly integrated IC, by utilizing one and the same impurity region for forming a base region for a bipolar transistor and a drain region for an MOS transistor. CONSTITUTION:An NPN transistor is composed of an N<+> type impurity region 3 for providing an emitter region, low- and high-concentration P-type impurity regions 4 and 5 for providing base regions, and an N-type epitaxial layer 6 and an N<+> type buried layer 2 for providing collector regions. A P-type channel transistor is composed of a gate polysilicon 7, a P<+> type region 8 for providing a source region and the high-concentraion P<+> type region 5 for providing a drain region. Thus, the same high-concentration P<+> type is commonly utilized for both the base region of the NPN transistor and the drain region of the P-type channel transistor. As a result, the degree of integration of the Bi-CMOS IC can be increased. |
