Disclosed herein is a semiconductor device with high reliability which
has TFT of adequate structure arranged according to the circuit performance required.
The semiconductor has the driving circuit and the pixel portion on the same substrate.
It is characterized in that the storage capacitance is formed between the first
electrode formed on the same layer as the light blocking film and the second electrode
formed from a semiconductor film of the same composition as the drain region, and
the first base insulating film is removed at the part of the storage capacitance
so that the second base insulating film is used as the dielectric of the storage
capacitance. This structure provides a large storage capacitance in a small area.
