SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

PURPOSE: To provide a large current drive capability and a threshold voltage characteristic which is similar to that of MOSFET for reducing hot carriers, generated in the vicinity of a drain, when the power supply voltage is kept constant by forming a gate electrode on a gate insulation layer of a laminated structure. CONSTITUTION: A first oxide film 21, a first polysilicon film 22 and a second oxide film 23 are stacked on a P-type semiconductor substrate 200 to form a gate insulation layer 2G. Next, a second polysilicon film 24 which is doped by a high concentration impurity on the second oxide film 23 is deposited, a gate electrode 24' is formed by an anisotropic etching by a photoetching method and a first impurity region 26 is formed by the ion-implantation of the N-type impurity of low concentration, using the electrode 24' as the mask. Next, after an insulation oxide film has been deposited, the anisotropic etching is conducted to form a spacer 27' to the sidewalls of the gate electrode 24' and gate insulation layer. Subsequently, ion-implantation is conducted, using the high concentration N-type impurity spacer 27' as a mask for forming a second impurity region 29.