Patent ID: 6482690
Filing Date: 2002-11-19
Classification: H01L

Abstract:
A method for fabricating a semiconductor device, comprising the steps of:forming an isolation region on a surface portion of a semiconductor substrate of silicon, thereby defining first and second regions, which are isolated from each other by the isolation region, on the semiconductor substrate; forming a tantalum oxide film and a silicon dioxide film in the first and second regions on the semiconductor substrate, respectively; forming a tantalum nitride film in a surface portion of the tantalum oxide film and changing the silicon dioxide film into a silicon oxynitride film by heat-treating the semiconductor substrate within an ambient containing nitrogen as a main component; forming a first gate electrode on the stack of the tantalum oxide and nitride films and a second gate electrode on the silicon oxynitride film, respectively; and forming first and second gate insulating films by etching the stack of the tantalum oxide and nitride films and the silicon oxynitride film using the first and second gate electrodes as respective masks.