| 摘要 |
PURPOSE:To protect a gate oxide film against strong impact during wire bonding operation, by composing an insulation film lying under a metal film of a thin insulation film lying over the periphery of an active semiconductor region and of a thick insulation film lying over the other regions. CONSTITUTION:A p<+> type semiconductor layer 23 is selectively formed on an n-type epitaxial layer deposited on the surface of an n<+> type silicon substrate 21 containing a high concentration of n-type dopant. A thick oxide film (SiO2) 24 is further formed on the layer 23. The oxide film 24 is then selectively etched and another thick gate oxide film (SiO2) 25 is formed on the exposed surface of the epitaxial layer 22. A polycrystalline silicon film 26 for providing a gate electrode is selectively formed thereon and a p-type semiconductor layer 27 for providing a channel region is formed. Further, n-type dopant ions are implanted selectively in the p-type semiconductor layer 27 and then a CVD-SiO2 film 28 is formed. After heat treatment, an n<+> type semiconductor layer 29 for providing a source is formed. |
