| 摘要 |
PURPOSE:To narrow a field region as far as possible by a method wherein a field oxide film is tapered independently of the formation of a thick oxide film so that an intrusion into an active region can be controlled irrespective of the thickness of the oxide film. CONSTITUTION:A thick oxide film 3 is removed selectively by an etching method and is left only on a channel stopper 2. If a silica film 4 is applied by using a spin coating method, much silica is collected at a stepped part of the oxide film 3 and the sheer stepped part becomes a smooth slope. The silica film 4 at a flat part is removed by the etching method and the surface of a semiconductor substrate 1 is exposed. A gate oxide film 6 is formed by thermal oxidation; furthermore, polysilicon 7 is applied and patterned. A source-drain region 8 of a MOSFET is formed. By this setup, a field region is narrowed as far as possible.
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