The etch rates and mechanisms for HfO2 thin films in Cl-2-, SF6- or CH4/H-2-based plasmas were measured as a function of source power. r.f. chuck power and discharge composition. Both Cl-2- and SF6-based plasmas produced some degree of chemical enhancement in the etch mechanism. Selectivities between 0.2 and 5 were obtained for Si over HfO, in these two plasma chemistries. High fidelity pattern transfer was achieved for photoresist-masked HfO2/Si structures etched with Cl-2/Ar over a broad range of pressures or with SF6/Ar at low pressures. The surface morphologies of both HfO2 and Si were smooth over a wide range of etching conditions. (C) 2002 Elsevier Science B.V. All rights reserved.