Method for manufacturing semiconductor elemental device forming an amorphous high dielectric film and an amorphous silicon film

Abstract

A base substrate is first prepared, and a high dielectric amorphous film composed of a high permittivity material is formed over the base substrate. Next, an amorphous silicon film is formed over the high dielectric amorphous film with an amorphization temperature of the high permittivity material as a deposition temperature. Then, the amorphous silicon film is processed by a photolithography method and dry etching to form gate electrode forming films. Wet etching with the gate electrode forming films as masks is next performed to allow portions of the high dielectric amorphous film, which are covered with the gate electrode forming films to remain and remove exposed portions of the high dielectric amorphous film. Next, the gate electrode forming films are thermally treated to reform amorphous silicon into polysilicon so as to constitute gate electrodes.