Microelectromechanical systems using piezoelectric thin films

Ferroelectric thin films have been integrated with silicon-based microelectromechanical systems, commonly called MEMS. Several thin films of the PZT family have been used in the formation of both microsensors and microactuators in processes compatible with silicon nitride, surface-micromachined, membranes and analog CMOS technology. Back-end micromachining of MEMS structures based on PZTtype electroceramic thin films is described. Several ferroelectric MEMS examples are described including 1) cantilever beam micro-accelerometer, 2) acoustic pressure sensor, 3) uncooled pyroelectric infrared imaging array, 2) integrated acoustic sensor, 4) micro-positioner, and 5) simple cantilever flap actuators. Major issues of merging technologies with ferroelectric thin films with microelectromechanical structures and on-chip electronics are described.