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

We report processing conditions and electromechanical properties of highly textured, 0.7 Pb ( Mg 1/3 Nb 2/3 ) O 3 –0.3 PbTiO 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 ~430 nm were synthesized on thin PbTiO 3 and Pb ( Zr , Ti ) O 3 seed layers. Overall, (100)‐textured films showed higher dielectric permittivity and saturated d 33,f piezoelectric coefficients. Dense, submicron‐thick, (100)‐oriented films showed low‐field, relative dielectric permittivity of up to ~2850 (tan δ = 0.02) at 1 kHz, and remnant polarization values up to 17.5 μC/cm 2 . The films showed saturated d 33,f piezoelectric coefficients as high as 210 pm/V.