Etch stop layer used for the fabrication of an overlying crown shaped

Abstract

A process for creating a crown shaped storage node structure, for a DRAM capacitor structure, featuring the use of a silicon oxynitride layer, underlying the crown shaped storage node structure, has been developed. A silicon oxynitride layer is placed overlying the interlevel dielectric layers that used to protect underlying DRAM elements, and placed underlying a capacitor opening in an overlying insulator layer. A selective RIE procedure is used to create the capacitor opening, in an insulator layer, with the RIE procedure terminating at the exposure of the underlying silicon oxynitride layer. After creation of the crown shaped storage node structure, in the capacitor opening, overlying the silicon oxynitride layer at the bottom of the capacitor opening, the insulator layer used for formation of the capacitor opening, is selectively removed from the regions of silicon oxynitride layer, not covered by the overlying crown shaped storage node structure, using wet etch procedures.