| 摘要 |
PURPOSE:To protect against an external surge and prevent the generation of a parasitic leakage current, by providing a P-N junction part with a high withstand voltage by reducing the impurity density of a region P-N joined with an impurity region which supplies input-output signals. CONSTITUTION:An N<+> diffused layer 31 and a low density P type impurity region 32 are provided between a P<+> layer 12 and an N<+> diffused layer 14 formed on a substrate 11. Further, a polysilicon film 34 is formed on the surface of the P type impurity region 32 via an insulating thin film 33 consitituted of an Si oxide, etc. This polysilicon film 34 is connected to a metallic film 18 and the N diffused layer 31 through open hole parts 35, 36 provided on the insulating film 16. Thus, the P-N junction part is provided with a high withstand voltage by reducing the impurity density of the P-N joined region 32 resulting in the protection against an external surge, and the generation of a parasitic leakage current is prevented. |
