METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE WITH GATE STACK STRUCTURE OF POLYSILICON AND TUNGSTEN FOR RESTRAINING CONTAMINATION OF TUNGSTEN

摘要

PURPOSE: A method for manufacturing a semiconductor device having a gate electrode of polysilicon/tungsten structure is provided to restrain the contamination of tungsten by using a selective oxide layer. CONSTITUTION: A gate insulating layer(22) is formed on a semiconductor substrate(20). A gate stack including a polysilicon layer(23) and a tungsten film(25) is formed on the gate insulating layer. A selective oxide layer(29) is formed to restrain the oxidation of the tungsten film by selective oxidation processing under a diluted source gas containing hydrogen to an inert gas or a nitrogen gas.