A p channel TFT of a driving circuit has a single drain structure and its
n channel TFT, an LDD structure. A pixel TFT has the LDD structure. A
pixel electrode disposed in a pixel unit is connected to the pixel TFT
through a hole bored in at least a protective insulation film formed of
an inorganic insulating material and formed above a gate electrode of the
pixel TFT, and in an inter-layer insulation film disposed on the
insulation film in close contact therewith. These process steps use 6 to
8 photo-masks.