Processing Optimization of Lead Magnesium Niobate-Lead Titanate Thin Films for Piezoelectric MEMS Application

We report processing conditions and electromechanical properties of highly textured, 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) (PMN-PT) films, processed via chemical solution deposition on platinized silicon substrates. Textured perovskite seed layers, optimization of heat treatment conditions and Pb content control were studied to obtain pure perovskite PMN-PT films with dense, columnar grains. Highly (100)- and (111)-oriented films, with Lotgering factors between 91% and 97%, and average grain size up to similar to 430 nm were synthesized on thin PbTiO3 and Pb(Zr,Ti)O-3 seed layers. Overall, (100)-textured films showed higher dielectric permittivity and saturated d(33,f) piezo-electric coefficients. Dense, submicron-thick, (100)-oriented films showed low-field, relative dielectric permittivity of up to similar to 2850 (tan delta = 0.02) at 1 kHz, and remnant polarization values up to 17.5 mu C/cm(2). The films showed saturated d(33,f) piezo-electric coefficients as high as 210 pm/V.