The etch characteristics of SrBi2Ta2O9 (SBT) films were investigated with BCl3/Cl-2/Ar inductively coupled plasma. When 10% BCl3 added in Cl-2/Ar plasma, the SBT etch rate increased and then decreased over 20% addition of BCl3. As RF power and dc bias increased and pressure decreased, etch rate of SBT increased. We obtained a maximum etch rate of 1137 Angstrom/min under the condition of 700 W and - 250 V The etch rate behavior of SBT was understood with the measurements of optical emission spectroscopy (OES) and X-ray photoelectron spectroscopy (XPS). The volume density of the Cl radical and BCl molecule were monitored with OES. The chemical status change on the SBT surface was investigated on the surface of SBT treated by BCl3/Ar plasma and found SrClx and B-O. These layers prohibit a possibility of chemical reaction or a reduction of physical sputtering by positive ions. (C) 2003 Elsevier B.V. All rights reserved.