Light valve device with a protection circuit including a semiconductor device.

摘要

An aim is to provide a MOS integrated circuit with improved static electricity tolerance without sacrificing the high speed characteristic of an IC on a SOI substrate. A semiconductor device in which the thickness of a silicon single crystal thin film device forming layer (103) of an input/output protection circuit forming region (104) in a MOS integrated circuit on a SOI substrate (101,102) is made greater than the thickness of the silicon single crystal thin film device forming region (103) of a MOS integrated circuit forming region (105). The benefits can also be attained when the semiconductor device is used in a light valve device such as an active matrix liquid crystal display device.