METHOD FOR FABRICATING TUNGSTEN PLUG OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method of forming a tungsten plug is provided to simplify process steps using low-priced slurry without metal ions in a chemical mechanical polishing process. CONSTITUTION: The method comprises the steps of forming an insulating layer on a semiconductor substrate; etching the insulating layer down to a partial top surface of the substrate to form a contact hole; forming a barrier metal layer on a surface of the contact hole and the insulating layer; forming a tungsten layer on the barrier metal layer to be buried in the contact hole in which the barrier metal layer is formed; polishing the tungsten layer and the barrier metal layer down to a top surface of the insulating layer using a chemical mechanical polishing process; oxidizing a metal layer for a plug of an outside of the contact hole to form a tungsten oxide layer; and polishing the tungsten oxide layer and the barrier metal layer.