Etching Characteristics of VO2 Thin Films Using Inductively Coupled Cl-2/Ar Plasma

Abstract

A study on both etching characteristics and mechanism Of VO2 thin films in the Cl-2/Ar inductively coupled plasma was carried. The variable parameters were gas pressure (4-10 mTorr) and input power (400-700W) at fixed bias power of 150 W and initial mixture composition of 25% Cl-2 + 75% Ar. It was found that an increase in both gas pressure and input power results in increasing VO2 etch rate while the etch selectivity over photoresist keeps a near to constant values. Plasma diagnostics by Langmuir probes and zero-dimensional plasma model provided the data on plasma parameters, steady-state densities and fluxes of active species on the etched surface. The model-based analysis of the etch mechanism showed that, for the given ranges of operating conditions, the VO2 etch kinetics corresponds to the transitional regime of ion-assisted chemical reaction and is influenced by both neutral and ion fluxes with a higher sensitivity to the neutral flux. (C) 2009 The Japan Society of Applied Physics