| 摘要 |
PURPOSE:To enhance the reliability, to reduce the decrease or variations in the current amplification factor by forming an oxidized film and an insulating film which contains extremely low boron content rate and using it as the surface protecting film of an emitter and base junction. CONSTITUTION:An insulating film 9 which is formed of a thermally oxidized layer 9a of a single crystal substrate 1, a CVD SiO2 layer 9b, a polysilicon oxide 9c and polysilicon layer 9d is formed on a base region 4 and a base electrode 7, the electrode 7 and an emitter electrode 10 are insulated and isolated, and a junction of the region 4 and an emitter region 3 is protected. Since a CVD method is employed, boron contained in the films 9b, 9d can be extremely reduced in density, thereby improving the reliability. The positional relationship between the emitter 10 and a p<+> type base compensating diffused layer 4a can be arbitrarily determined with good controllability, and decreases in the reverse withstand voltage and the current amplification factor of the emitter and base junction does not occur. |
