Integration, electrical and electromechanical properties of PZT and PMN-PT thin films for MEMS applications

Piezoelectric and electrostrictive thin films are potential candidates for actuator functions in micro-electro-mechanical systems (MEMS) offering displacements and forces which outperform standard solutions, e.g. in micro mirrors and micro relays. Within this context the paper reports on the preparation and the integration processes of chemical solution deposited (CSD) Pb(Zr-x Til-x)O-3 (PZT) and (PbMg1/3Nb2/3)(l-z)-(PbTiO3)(z) (PMN-PT) thin films in combination with silicon bulk micro machining technique. The operativeness of the processes is demonstrated by the development of an integrated micro actuator for a micro switch application, Furthermore, the work deals also with the characterization of the integrated materials. For fabrication control and electrical characterizations microscopy, SEM, hysteresis- and CV-, and degradation measurements were performed. Laser interferometry and resonance frequency measurements were used to characterize the electromechanical performance of both materials in comparison to the behavior of the developed micro actuator.