Patent ID: 6987056

Claim:
A method of forming a gate in a semiconductor device, comprising: forming a gate pattern on a gate oxide film disposed on a semiconductor substrate, the gate pattern including a polysilicon film, an anti-diffusion film stacked on the polysilicon film and a metal film stacked on the anti-diffusion film and the gate pattern being stacked on a given region of the semiconductor substrate, wherein a cleaning process using a HF solution is performed on the polysilicon film before the anti-diffusion film is stacked thereon to remove a native oxide from the polysilicon film, forming a hard mask on top of the gate pattern; and performing an oxygen plasma treatment to a form an oxide film on sides of the conductive layer and not on the hard mask, wherein the oxygen plasma treatment is performed using oxygen and hydrogen with a flow ratio of oxygen:hydrogen being in a range of from 0.01 to 0.2.