Oxidation process to improve polysilicon sidewall roughness

A new step is provided for the creation of polysilicon gate electrode structures. A layer of polysilicon is deposited over the surface of a layer of semiconductor material, the layer of polysilicon is etched using a layer of hardmask material for this purpose. The etch of the layer of polysilicon is performed using a dual power source plasma system. During the etching of the layer of polysilicon, a step of inert oxidation is inserted. This step forms a layer of passivation over the sidewalls of the etched layer of polysilicon. The step of inert oxidation is an oxygen-based plasma exposure.