METHOD OF FORMING A SEMICONDUCTOR DEVICE

摘要

A method comprises: a step of forming a dummy gate of a transistor at the surface of a wafer; a step of removing the dummy gate; and a step of filling a trench left by the removed dummy gate with a metallic material. A chemical mechanical polish (CMP) is then performed on the metallic material, wherein a remaining portion of the metallic material forms a metal gate of the transistor. After the CMP, a treatment is performed on an exposed top surface of the metal gate using an oxidation-and-etching agent comprising chlorine and oxygen.