Patent ID: 7851891

Claim:
A semiconductor device, comprising: an insulating film formed on a substrate; a first semiconductor region into which an impurity is implanted, and which is formed on the insulating film; and a second semiconductor region of an undoped type formed on the insulating film so as to surround the first semiconductor region, wherein the insulating film includes a first portion and a second portion, and the first portion of the insulating film has a thickness larger than that of the second portion of the insulating film, a polysilicon resistor is formed in the first semiconductor region including the second portion, and the average density of leakage current from the first semiconductor region of a first conductivity type to the outside of the first and second portions of the insulating film has an absolute value of 1×10 =10 (A/mm 2 ) or more when the potential difference between the first semiconductor region of the first conductivity type and the outside of the first and second portions of the insulating film has an absolute value of 1.5 V.