PURPOSE: To stabilize the operation of the insulated gate type semiconductor device by laminating and forming nonsingle crystalline semiconductors, the principal ingredient thereof is silicon to which fluorine having heat-resisting property is added, onto a conductive layer on a substrate.

CONSTITUTION: The first nonsingle crystalline semiconductor 3, the principal ingredient thereof is silicon to which fluorine is added and which has an N type conductive layer, is formed onto the insulating substrate 1 on which the conductive layer 2 is formed selectively. The intrinsic or substantially intrinsic second nonsingle crystalline semiconductor 4, the principal ingredient thereof is silicon to which fluorine is added, is formed onto the semiconductor 3. The third nonsignal crystalline semiconductor 5 with the same N type conduction type as the first semiconductor 3 is laminated and formed gradually onto the second semiconductor 4 through a plasma vapor method. Source-drain are constituted by the first and third same conduction type semiconductors 3, 5, and a gate insulating film 16 is formed onto the second semiconductor 4 and a gate electrode 17 onto the insulating film 16.