| 摘要 |
PURPOSE:To flatten a semiconductor element and reduce the chip area, by a method wherein the upheaving part and lateral spreading part of an oxide film due to the selective oxidation of a semiconductor substrate are eliminated by a selective etching, and polycrystalline silicon is deposited on the exposed silicon part. CONSTITUTION:When a field oxide film 5 is selectively formed on the surface of an epitaxial growth layer 4, a bird's head 6 and a bird's beak 7 generate at the end-portion. However, the bird's head 6 and the bird's beak 7 in the field film 5 neighbouring with a base region 10 are selectively eliminated by etching, and as the result, a recessed part where silicon is exposed on the surface is generated. After polycrystalline silicon is thickly deposited on the surface of a semiconductor device, the polycrystalline silicon is selectively eliminated by photo-lithography in the manner in which the polycrystalline silicon 13 is left only on said recessed part. Thereby the part of a base where the bird's head 6 and the bird's beak 7 are eliminated is flatten, and the chip area can be reduced.
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