| 摘要 |
PURPOSE:To reduce the increase of junction leakage by radiation exposure by separating a high-concentration impurity diffusion layer region from a thick selective thermal oxidation region and coating the region of a thin oxide film between the high- concentration impurity diffusion layer region and the selective thermal oxidation region with a conductor layer at the same potential as a substrate. CONSTITUTION:An oxide film region 2 and a selective thermal oxidation oxide film 3 are shaped onto a P-type substrate 1 in impurity concentration of approximately 10<16>cm<-3>. The pattern 4 of an N-type polycrystalline silicon layer is formed onto a boundary between the thin oxide film region 2 and the thick oxide film region 3 so as to be projected to the region 2 side by 5mum. An N-type impurity diffusion layer region 5 in approximately 10<20>cm<-3> concentration is shaped through ion implantation from the upper section of the polycrystalline silicon pattern 4, and the boundary of the diffusion layer region 5 extends up to the lower section of the polycrystalline silicon pattern 4. contacts 6, 7 are each shaped for taking the potential of the N<+> diffusion layer 5 and the N-type polycrystalline silicon 4, and a phosphorus glass layer 9 in 1mum thickness is formed under an aluminum wiring layer 8. The potential of the N-type polycrystalline silicon is made the same as the substrate.
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