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.