Characterization of Nb-doped Pb(Zr,Ti)O3 films deposited on stainless steel and silicon substrates by RF-magnetron sputtering for MEMS applications

Piezoelectric Nb-doped Pb(Zr,Ti)O3 thin films (PNZT) were deposited on stainless steel and silicon wafer substrates using RF-magnetron sputtering with the aim of micro-electromechanical systems (MEMS) applications. The obtained films on both kinds of substrates were strongly uniaxially oriented, for stainless steel substrate in (0 0 1) direction, and for silicon substrate in (1 0 0) direction, respectively. Resonance measurements of diaphragm structures with PNZT films found Young's modulus of the obtained film to be 49 GPa. Displacement measurements on both diaphragm structures resulted in piezoelectric coefficients of d31 = −217 pm/V for stainless steel substrate and d31 = −259 pm/V for silicon substrate, demonstrating that both substrates are feasible for MEMS applications with sputtered PNZT film.