| 摘要 |
PURPOSE:To prevent the decrease in capacity value and to perform stable circuit operation, by surrounding the peripheral part of a p type diffused layer by an n<+> type diffused layer, whose conductive type is reverse to that of the p type diffused layer. CONSTITUTION:A ring-shaped n<+> type diffused layer 7 is formed along the peripheral part of a p<+> type diffused layer 2 so as to cover the surface of an n type substrate. An Al electrode 5, which is connected to the p type diffused layer, is formed so as to short the n<+> type diffused layer. The p<+> type diffused layer can be formed by utilizing the base diffusion or the p type well diffusion in an n-p-n transistor process. The n<+> type diffused layer can be formed by utilizing the emitter diffusion in the n-p-n transistor process by the same way. In this MOS capacity device, a potential V becomes high and an inverted layer 8, which is generated on the surface of the p<+> type diffused layer, is connected to the n<+> type diffused layer 7 having the reverse conductive type. In this way, the reduction in capacity value after inversion is immediately recovered to the original state. |
