METHOD FOR FORMING GATE STACK OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A gate stack formation method of semiconductor devices is provided to prevent a generation of voids between a polysilicon layer and a metal silicide by using a CVD(Chemical Vapor Deposition) oxide and a thermal oxide. CONSTITUTION: After forming a gate oxide(410) on a semiconductor substrate(400), a polysilicon layer(420) and a metal silicide film(430) are sequentially formed on the gate oxide(410). A silicon nitride(440) and a silicon oxide(450) are sequentially formed on the metal silicide film. By sequentially etching the silicon oxide, the silicon nitride, the metal silicide film and the polysilicon layer, a gate stack is formed. A CVD oxide(470) is formed on the entire surface of the resultant structure. By performing a thermal oxidation, a thermal oxide(480) is formed at both sidewalls of the polysilicon layer(420) and the metal silicide film(430).