| 摘要 |
PURPOSE:To reduce the resistance of a collector without lowering with-standing voltage between a collector and a base, and the collector and an emitter by diffusing a reverse conduction type impurity from first and second impurity diffusing window regions and connecting the diffusion regions through all openings. CONSTITUTION:An SiO2 film 2 is formed extending over the whole region of the surface of a P<-> type silicon substrate 1. A large number of fine striped openings 3 are formed in a region B, and wide openings 4 are shaped in regions C. Phosphorus is evaporated on the surfaces of the silicon substrates exposed into the openings, and phosphorus is diffused in an oxidizing atmosphere. Diffusion regions for phosphorus formed through several opening are all connected. The SiO2 films on the silicon substrate are all removed, and an N<-> type epitaxial layer is grown on the silicon substrate. The whole region on the silicon substrate is coated with an SiO2 film again. An N<+> type collector wall diffusion region, a P type base region and an N<+> type emitter region are thus formed. |
