Etching characteristics and mechanism of Pb(Zr,Ti)O-3 thin films in CF4/Ar inductively coupled plasma

摘要

The effect of the CF4/Ar mixing ratio on the etching behaviour and mechanisms for Pb(Zr,Ti)O-3 (PZT) thin films in an inductively coupled plasma was carried out. It was found that an increase of Ar mixing ratio causes non-monotonic behaviour of the PZT etch rate, which reaches a maximum of 2.38 nm/s at 80% Ar. Investigating the plasma parameters, we found a weak sensitivity of both electron temperature and electron density to the change of CF4/Ar mixing ratio. A combination of zero-dimensional plasma model with the model of surface kinetics shows the possibility of a non-monotonic etch rate behaviour due to the concurrence of physical and chemical pathways in the ion-assisted chemical reaction. (C) 2004 Elsevier Ltd. All rights reserved.