A study of lead zirconate titanate etching characteristics using magnetized inductively coupled plasmas

In this study, Pb(Zr1-xTix)O-3 (PZT) thin films were etched using magnetize d inductively coupled plasmas (MICP) and their etch characteristics were co mpared with those by non-magnetized conventional inductively coupled plasma s (TCP). The use of Helmholtz type axial electromagnets around the chamber wall increased the PZT etch rates while decreasing etch uniformity. By usin g both the multidipole magnets and the axial electromagnets around the cham ber wall, the etch uniformity could be improved while maintaining high PZT etch rates. PZT etch rates close to 1700 Angstrom /min which are three time s higher than those etched using the conventional ICP plasmas could be obta ined with optimized MICP conditions. The etch selectivities over Pt at thes e conditions were higher than 1.5. The MICP used in the experiment showed h igher Cl radicals and Cl-2(+)/Cl+ ratios in the plasmas compared with those in the conventional ICP plasmas. Therefore, the increased chemical and/or physical sputtering by the increased Cl-2(+)/Cl+ ratios along with the incr eased chemical reactivity by higher Cl radical densities appears to be resp onsible for high PZT film etch rates obtained with the MICP in our study. U sing the MICP in 90%Cl-2 + 10%Ar gas mixture, a nearly vertical etch profil e could be also obtained. (C) 2000 Elsevier Science B.V. All rights reserve d.