Effect of gas mixing ratio on etch behaviors of Ba2Ti9O20 (BTO) and Pt thin films in Cl-2/Ar inductively coupled plasma

Abstract

An investigation of the Ba2Ti9O20 (BTO) and Pt thin films etch mechanism in the Cl-2/Ar inductively coupled plasma was carried Out. It Was found that an increase in At mixing ratio at fixed gas pressure and input power causes a fast decrease in the BTO etch rate (26.9-1.2 nm/min for 0-100% Ar) while the Pt etch rate increases slightly from 17.4-23.0 nm/min. Langmuir probe diagnostics and zero-dimensional plasma modeling provided the data on plasma parameters, steady-state composition and fluxes of active species on the etched surface. From the model-based analysis of etch kinetics, it was shown that the behavior of the BTO etch rate corresponds to the reaction-rate-limited etch regime, where the etch rate is limited neither by physical sputtering of the main material nor by the ion-stimulated desorption of low-volatile reaction products. The etch process of Pt appears in the transitional regime and is controlled by the neutral and ion fluxes together. (C) 2008 Elsevier B.V. All rights reserved.