| 摘要 |
PURPOSE:To obtain a circuit usable for MNOS and C-MOS elements by forming a region floated potentially additionally to a semiconductor substrate provided with source and drain regions as an input protecting circuit. CONSTITUTION:P<+> type source and drain regions 5 and 6 are diffused in an N type Si substrate 1 at ground potential, and a gate Si3N4 film 8 is coated through a gate SiO2 film 7 being extremely thin on the substrate 11 exposed therebetween. Subsequently, the regions 5 and 6 are spaced, and are provided with P type region 2 used as floating state without connecting to any potential point at the substrate 1, an N<+> type region 3 is provided therein, and a shallow N<-> type region 4 is diffused in the surface layer of the region 2 surrounding the region 3. Thus, a diode D1 is formed between the regions 3 and 4, and a diode D2 is formed between the egion 3 and the substrate 1, an SiO2 film 10 is covered on the entire surface as an input protective circuit, a window is opened, and an input voltage applying metal wire 9 is connected to the region 3. |
