The etching characteristics of LaNiO3 (LNO) thin films and SiO2 in Cl-2/Ar plasma were investigated. LNO etch rates decreased with increasing Cl-2 fraction in Ar plasma and the working pressure. Langmuir probe measurement showed a noticeable influence of Cl-2/Ar mixing ratio on electron temperature, electron density, and ion current density. The modeling of volume kinetics for charged particles and OES measurements for neutral atoms indicated monotonous changes of both-densities and fluxes of active species such as chlorine atoms and positive ions. The LNO etch rate behavior may be explained by physical mechanisms. (c) 2005 Elsevier B.V. All rights reserved.