| 摘要 |
PURPOSE:To obtain a transistor having preferable frequency characteristic by reduce the resistance of a polysilicon film connected to an emitter layer with metal silicide film. CONSTITUTION:When an emitter electrode is formed on a nonactive region in a double base structure for leading a base electrode from both sides of an emitter layer, a nitride film 203 is formed by a reduced pressure CVD method on a polysilicon film 602, and only polysilicon film portions 602, 603 which become diffusion source including the film 203 remain. In case of double base structure, a double layer of a polysilicon film on an emitter layer and a metal silicide film is connected not on the emitter layer but on the nonactive region with an emitter electrode. Accordingly, it is selectively etched to allow the portions 602, 603 which become diffusion source including the film 203 and the portion connected with low resistance metal wiring on the nonactive region of the film 602 connected with an emitter layer 71 to remain, and with the film 302 as a mask a base contacting window is opened.
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