Method of forming gate electrode structure of a semiconductor device

Abstract

A method of forming a gate structure of a semiconductor device includes forming a gate insulation film and a polysilicon film on a semiconductor substrate where an active region and a field region are defined, followed by forming a buffer layer on the polysilicon film to minimize damage to the polysilicon film during a subsequent ion implantation process. The polysilicon film is made electrically conductive by the implanting of impurities into the polysilicon film. Gate patterns are then formed by etching the conductive polysilicon film and the gate insulation film. Defects, such as active pitting, associated with dual electrodes are effectively prevented because the polysilicon film is protected during the ion implanting process.