| 摘要 |
PURPOSE:To form an impurity diffused polysilicon layer without reducing an epitaxial layer region by growing an epitaxial layer in the opening of an insulating film layer on a substrate, then reducing the thickness of the layer therearound, forming a high concentration impurity layer and a polysilicon layer thereon, and conducting heat treatment then. CONSTITUTION:After a nondoped SiO2 film 2-1, a B-doped SiO2 layer 2A and a nondoped SiO2 film 2-3 are formed on an Si substrate 1, an epitaxial layer 4 is grown in an opening 3. Then, the film 2-3 is removed, it is covered with a polysilicon layer 5, and heat treated to form an impurity diffused polysilicon layer 5A. After the nondoped polysilicon is removed to be flattened, an SiO2 film 7 is formed on the surface, and an ion implanted region 10 is formed with a resist 8. After it is covered with a polysilicon layer 11, it is heat treated to form an emitter region 15, and the remaining region 10 is used as a base region. Finally, an emitter electrode 12, a base electrode 13 and a collector electrode (not shown in the figure) are formed.
|
