Selective CVD tungsten contact plug technology with plasma pre-treatment

Abstract

Low-resistance contact plug technology using selective CVD of W by the SiH/sub 4/ reduction of WF/sub 6/ with SF/sub 6/ pretreatment was developed. This technology solved problems such as encroachment, wormholes, Si consumption, and poor adhesion encountered in only the H/sub 2/-reduction system or only the SiH/sub 4/-reduction system without pretreatment. The contact resistance in this system is lower than that in conventional metallization with Al-Si/Si contacts. It is predicted that this technology will become important for improving the reliability of the interconnection for submicron VLSI.<>