Etching characteristics of lead magnesium niobate–lead titanate (PMN–PT) relaxor ferroelectrics

Etching characteristics of Pb{(Mg1/3Nb2/3)0.9Ti0.1}O3 (PMN–PT) were studied by an inductively coupled plasma etcher using Ar, Cl2, and BCl3 gas combinations. Using Ar/BCl3 and Cl2/BCl3, PMN–PT etch rates higher than 2500 Å/min could be obtained with the etch selectivity over photoresist higher than 1.0. In general, the increase of BCl3 in Ar/BCl3 and Cl2/BCl3 increased etch selectivity without decreasing PMN–PT etch rates significantly. X-Ray photoelectron spectroscopic analysis revealed that, during the PMN–PT etching, Ar ion bombardment enhanced the etching of Pb and Ti components preferentially, BCl3 plasma enhanced the etching of O, Nb, and Mg components, and Cl2 plasma enhanced the etching of Pb component. The etched profile angle of PMN–PT increased with the increase of PR selectivity.