The Research on Parameters Measurement Method of Piezoelectric Thick Film Used to SAW Gas Sensor Based on MEMS Technology

摘要

A structure of SAW gas sensor based on the PZT film is provided, on which includes input interdigital transducers, output interdigital detector and gas sensing films. The PZT piezoelectric thick film is fabricated on the structure of Au/Cr/SiO2/Si multilayer membrane. The piezoelectric parameters measurement method of the thick film are investigated systematically, i.e., the electric hysteresis loop, the dielectric constant, piezoelectric constants and the thickness of PZT thick film. The measurement results for the maximal piezoelectric constant d"33 is 201pC/N at thickness of 4μm, and the average of dielectric constant εr is 1080. The remanent polarization and the coercive field are up to 60μC/cm2 and 23kV/cm at 25V, respectively.