| 摘要 |
PURPOSE:To reduce a mask-matching work by a method wherein a diffusion source, with which an emitter and a base consisting of polysilicon will be formed, is formed on the upper surface of a substrate, and after an insulating film has been coated between the above-mentioned polysilicon layers, a flattening process is performed. CONSTITUTION:After a plurality of polysilicon layers 21,... have been formed on a substrate 1, an insulating film 13 is formed on the whole surface of the layer 21, a resist film 14 is coated thereon, and the surface is flattened. Then, the upper surface of the non-doped polysilicon layer 21 is exposed. Subsequently, the expected region where an emitter will be formed is coated with a resist film, ions are implanted, a base contact region 15 is formed, then a base region only is coated with a resist film, ions are implanted, and an emitter region 16 is formed. Lastly, an emitter electrode 17E and a base electrode 17B are formed. As a result, the mask matching requiring high preciseness can be reduced from the twice required in the past to once. Also, the lowering of the yield of production due to the short-circuit generating between the emitter and the base can be prevented.
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