MODELING OF OXIDE CHARGING EFFECTS IN PLASMA PROCESSING

An analytical model of oxide charging in plasma processing is presente d. The model simulates the interactions of the plasma with semiconduct or device structures on the wafer and the substrate bias to determine the charging induced in thin gate oxides. This model agrees well with experimental data for pulsed substrate bias. The simulation shows that a lower plasma electron temperature can reduce the charging damage. W ell structures modulate the charging damage, with p wells charging mor e negatively and n wells charging more positively than an identical ca se without a well structure. Two-dimensional charging effects such as plasma nonuniformities and antenna structures have also been successfu lly modeled. Antenna-type device structures are shown to enhance the c harging damage in both capacitor and well structures. (C) 1996 America n Vacuum Society.