Patent ID: 6680259
Filing Date: 2004-01-20
Classification: H01L,Y10S

Abstract:
A method of reactive ion etching SiO2 comprising the steps of:providing a silicon substrate comprising a semiconductor device including a gate structure between a first and a second portion of said silicon substrate, forming a barrier of silicon nitride directly on said substrate said barrier of silicon nitride having a first section and a second section superimposed on each other and coextensive entirely with each other with one of said sections being in contact with said first and second portions of said silicon substrate and the other section being spaced from said silicon substrate, said second section having a ratio of Si:N of at least about 0.8 and providing desired etch selectivity, the Si:N ratio of the silicon nitride in said first section being less than about 0.8 and providing desired resistance to positive mobile ion penetration, forming a layer of SiO2 on said barrier, and forming at least one opening by reactive ion etching said layer of SiO2 using said silicon nitride barrier as an etch stop layer.