In this study (Pb,Sr)TiO3 (PST) thin films were etched with inductively coupled Cl-2/(Cl-2+Ar) plasmas. The etch characteristics of PST thin films as a function of Cl-2 / (Cl-2 + Ar) gas mixtures were analyzed by using a quadrupole mass spectrometer. Systematic studies were carried out as a function of the etching parameters, including the radio frequency power and the working pressure. The maximum PST film etch rate is 56.2 nm/min, because a small addition Of Cl-2 to the Cl-2/Ar mixture increased the chemical effect. It was proposed that sputter etching is the dominant etching mechanism while the contribution of a chemical reaction is relatively low due to low volatility of the etching products. (c) 2005 American Vacuum Society.