| 摘要 |
PROBLEM TO BE SOLVED: To suitably prevent the generation of a leak current from a diffusion layer even when a p-n junction semiconductor element is formed in a semiconductor substrate on a semiconductor integrated circuit device of SOI (semiconductor on an insulating film) structure. SOLUTION: On this semiconductor integrated circuit device having a SOI structure, a semiconductor layer, i.e., SOI layers 3A and 3B are formed on a semiconductor substrate of p-type, for example, through a buried insulating film 2, and semiconductor circuit elements 9A and 9B, which are the functional elements against the above-mentioned SOI layers 3A and 3B, are formed. Also, a MOSFET 14, on which n-type diffusion layers 15 and 16 are formed in the semiconductor substrate 1, may be formed as a protective transistor, for example, of these elements 9A and 9B. In this case, the above-mentioned n-type diffusion layers 15 and 16 of the MOSFET 14 are surrounded by p-type diffusion layers 20 and 21 doped heavier than the semiconductor substrate 1. |
