Sputter Deposition and Characterization of Sm-Doped Pb(Mg_1/3, Nb_2/3)O₃–PbTiO₃ Epitaxial Thin Film on Si Toward Giant-Piezoelectric Thin Film for MEMS Actuator Application

To meet the growing demand for better piezoelectric thin films for microelectromechanical systems (MEMSs), we have developed an SM-doped Pb(Mg _1/3 , Nb _2/3 )O ₃ –PbTiO ₃ (Sm-PMN-PT) epitaxial thin film as a next-generation piezoelectric thin film to replace Pb(Zr, Ti)O ₃ (PZT). The inherent piezoelectricity $\left |{ {e}_{{31},{f}} }\right |$ achieved 20 C/m ² , which is greater than those of intrinsic PZT thin films and the best Nb-doped PZT thin film. Besides, the simulation results show that the $\left |{ {e}_{{31},{f}} }\right |$ value of the single Sm-PMN-PT film could be around 26 C/m ² . Meanwhile, the breakdown voltage of the as-deposited thin film was higher than 300 kV/cm. These results suggest the high potential of the Sm-PMN-PT epitaxial thin film for piezo-MEMS actuators with large displacement or force.