Etch behavior of PB(ZrxTi1-x)O-3 films using a TiO2 hard mask

Dry etching of lead zirconate titanate (PZT) thin film and Pt/PZT stack str ucture was investigated using a TiO2 hard mask in an inductively coupled pl asma (ICP). An annealed TiO2 thin film was employed as an etch mask for PZT and Pt/PZT stack etching. Etch characteristics of PZT thin films were exam ined with Cl-2/O-2/Ar etch chemistry in terms of the etch rate, the etch se lectivity, and the etch profile. The etch selectivity of the PZT film to th e TiO2 mask was in the range of one to five at the etch conditions used in this study. It was found that the etch selectivity of the PZT film to the T iO2 mask was strongly affected by the ratio of O-2 to Cl-2 concentration. A n X-ray photoelectron spectroscopy study revealed that the O-2 gas played a n important role in obtaining high selectivity of PZT/TiO2 films. Finally, the pattern transfer of Pt/PZT stack structure with the submicrometer dimen sion was achieved using a TiO2 hard mask. The sidewall angle of etched Pt/P ZT stack was approximately 75 degrees without etch redeposition or residue. (C) 2001 The Electrochemical Society. [DOI: 10.1149/1.1360207] All rights reserved.