Optimization of functional layers in piezoelectric thick film MEMS process

For pure PZT (Pb(Zr_0.52Ti_0.48)O₃) which demonstrates excellent piezoelectric performances, powder-based film requires very high sintering temperature (~1250°C) in order to obtain high density and good electromechanical properties of the film. However, high processing temperatures via volatilization PbO at 900°C, that temperature arise inter-diffusion or reaction between PZT active materials and Si substrate resulting in device failure, should be avoided in micro electro mechanical system (MEMS) fabrication for better performance of silicon-based micro-devices. In this research, for the best method to fabricate stable and reliable PZT thick film devices, the investigation of compatibility including interface stability and adhesion between the layers, which compose the whole integrated devices, were examined.