Stability of Co/Ni Silicide in Metal Contact Dry Etch

Abstract

Newly developed silicide materials for ULSI should have the appropriate electrical property of low resistant as well as process compatibility in conventional CMOS process. We prepared silicides from 15 nm-Co/15 nm-Ni/Si structure and performed contact dry etch process to confirm the dry etch stability and compatibility of layers. We dry etched the photoresist/SiO/silicide/silicon patterns with gases with varying powers from 100 to 200 W, and pressures from 45 to 65 mTorr, respectively. Polysilicon and silicon active layers without silicide were etched during over etch time of 3min, while silicon layers with proposed silicide were not etched and showed stable surfaces. Our result implies that new silicides may replace the conventional silicides due to contact etch process compatibility.