METHOD FOR FORMING POLYSILICON CONTACT PLUG OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming polysilicon contact plug of a semiconductor device is provided to stably form the polysilicon plug without damage of a hard mask nitride by using downstream microwave and RF bias plasmas. CONSTITUTION: A gate structure having a hard mask nitride(4) and a nitride spacer(5) is formed on a semiconductor substrate(1). An interlayer dielectric(7) is formed on the resultant structure and a contact hole is formed by self-aligned contact etching of the interlayer dielectric(7). A polysilicon is sufficiently filled into the contact hole. By etch back the polysilicon using a downstream microwave and an RF bias plasma processes, a polysilicon contact plug(8) is formed.