| 摘要 |
PURPOSE:To reduce an external resistance of a base by diffusing an impurity into the base from above the region between a graft base and an emitter in such a manner as to be indentical in the conductivity type to base in the production of a transistor having a graft base. CONSTITUTION:An n<+> epitaxial layer 2 is grown on an n<+> type semiconductor substrate. With an SiO2 film 8 on the surface thereof, the p type impurity is diffused to form a p type graft base 3 and boron ion is implanted to a p type ion-implanted region 14. Then a boron silicate glass film 13 and an SiO2 film 15 are grown on the SiO2 film 8 and a portion on the base region 14 is etched away to make an emitter window. Then, an Si layer 17 containing oxygen and phosphorus and a poly Si layer 18 doped with phosphorus are grown sequentially and phosphorus in the Si layer 17 is diffused by heat treatment to form an n<+> type emitter region 6. |
