CVD Tungsten Via Void Minimization for Sub 0.25 μm Technology

摘要

The mechanism of void formation in tungsten plugs during W CVD process is analyzed qualitatively and analytically. A simple mathematical model for W plug fill is presented for order of magnitude analyses. The model is shown to make good "relative" predictions for process pressure and temperature to be used to fill various aspect ratio contacts. The electrical data shows that contacts with smaller voids result in lower via chain and Van der Pauw resistances.