MIS FIELD EFFECT TRANSISTOR AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To provide a field effect transistor which is easily controlled in threshold voltage and provided with a gate electrode that is less depleted. SOLUTION: This transistor is equipped with gate electrode films 40 and 50 which are both of multilayered structure formed of conductive film. Lower conductor films 41 and 51 coming into contact with a gate insulating film 30 are set thin enough to change a substrate channel region in potential by the upper conductor films 42 and 52, and the lower conductor film 51 of the gate electrode film 50 is set different in thickness from the lower conductor film 41 of the gate electrode film 40.