Reliability of crystalline TFTs is improved in a large area integrated
circuit typified by an active matrix type liquid crystal display device.
In TFTs having an LDD structure, a region whose LDD region overlaps with
a gate electrode and a region not overlapping with the gate electrode are
fabricated inside one TFT. To accomplish this structure, n-channel TFTs
are fabricated in non-self-alignment whereas p-channel TFTs are
fabricated in self-alignment.