Semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To prevent impurities from diffusing to other regions by a method wherein the second polycrystalline silicon film which does not contain impurities at all or containing them in low density, is formed in high density on the first polycrystalline silicon film. CONSTITUTION:A field oxide film 2 and the first gate oxide film 4 are formed on a silicon single crystal substrate 1, the first polycrystalline silicon film 5 is deposited on the above, and high density of impurities are introduced. The second polycrystalline silicon film 6 is deposited on the whole surface of the first polycrystalline silicon film 5, an etching is performed on the polycrystalline silicon films 5 and 6 and the first gate oxide film 4, excluding the part which will be turned to the first gate electrode and wiring, and the second gate oxide film 7 is formed on the substrate 1 and, at the same time, an oxide film 8 to be used for an intermediate insulating film is formed. Then, the second gate electrode and wiring, consisting of third polycrystalline silicon film 9 is formed and a diffusion layer 10 is formed on the substrate 1 by introducing impurities.

Inventors

• 👤 Akio Kita
• 👤 北　明夫

Bibliographic Details