| 摘要 |
PURPOSE:To improve integration degree, by taking out a base contact from the oblique upper part of a base region by using polycrystalline silicon. CONSTITUTION:An embedded layer 2 is diffused in an Si substrate 1. An Si epitaxial growing layer 3 is formed on the layer 2. Four layers of an SiO2 film 4, an Si3N4 film 5, an SiO2 film 6 and an Si3N4 film 7 are formed. Then, a resist pattern 8 is formed, and the film 7 and the film 6 are etched. The film 6 is further side-etched. With the Photoresist 8 as a mask, the film 5 and the film 4 are vertically machined by dry etching, and the resist is removed. A part of the film 3 is etched. Thereafter, an SiO2 film 9 is formed by selective oxidation. After the film 5 is etched, the SiO2 film 7 is etched. Then a slant surface 10 of Si is exposed. Thereafter, a poly Si film 11 is deposited on the surface. A hole 12 is provided, and an intrinsic base region 14 is formed. Then, the poly Si is oxidized, and an SiO2 film 15 is formed. A hole is provided through the Si3N4 film 5 and the SiO2 film 4, and an emitter diffused layer is formed. An emitter electrode 17, a base electrode 18 and a collector electrode are formed. Thus, the integration degree is improved, and decrease in stray capacity can be realized.
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