| 摘要 |
PURPOSE:To lower breakdown voltage by injecting an impurity having the same conduction type as an E region into a base region except an emitter region, diffusing the base through heat treatment and forming a swelled section to a base-collector junction overlapping on a collector region. CONSTITUTION:P<+> Separation regions 4, 4', a deep N<+> diffusion layer region 3' and a buried layer 3 connected to the region 3' are formed to a substrate 1. An N<+> region 12a is shaped through the implantation of phosphorus ions. A base region diffusion layer 15 is formed through the injection of boron. When the whole is thermally treated in order to diffuse the base, the base 5 is shaped in a region where phosphorus is not implanted, and a shallow section is molded to a B-C junction and changed into the swelled section 7a in a region where phosphorus is implanted. Accordingly, low breakdown voltage can be set, and the breakdown voltage is not affected by the conditions of the surface. |
