SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress a leak current in a semiconductor integrated circuit device formed on a semiconductor substrate having an input protection circuit element such as a diode formed thereon. SOLUTION: An N type MOS 9b and a P type MOS 9b are formed to be a single crystalline silicon layer of an SOI(silicon on insulator) type, and an N type diffusion layer 18 and a P type diffusion layer 19 are formed in a semiconductor substrate 1 to form a protective diode 17 which forms an input protection circuit of a CMOS inverter circuit 13 The N type diffusion layer 18 is surrounded by the P type diffusion layer 19 so that the P type diffusion layer 19 cuts off a depletion layer formed at an interface of an embedded insulating film 2 within the semiconductor substrate 1, thereby suppressing a leak current between the P and N type diffusion layers 18 and 19.