Commercial prototyping of piezoelectric microsystems

Micro electro-mechanical systems (MEMS) with integrated piezoelectric thin films (piezoMEMS) have displayed particular versatility, as a result of the large displacements, high sensing functionality and high energy densities that can be obtained, compared to pure Si-MEMS. They fulfil many of the requirements for sensors and actuators in tomorrow’s smart systems.   The prototyping costs and needed competence for industries that would like to exploit this new technology can be both unaffordable and hard to create. SINTEF and collaborators have reduced this problem by applying a processing scheme inherited from conventional silicon foundry labs; multi project wafer (MPW) processing, to piezoMEMS, creating the SINTEF MoveMEMS process. On an MPW, several different device prototypes are produced using the same set of design rules. Through batch processing, a large number of prototypes can be made, but at a much lower cost for each participant. Since all the devices on an MPW will undergo the same sequence of material depositions and etching steps, multiple MPWs may be needed to meet different design requirements. This presentation will show the processing of MPWs and give examples of devices that is fabricated.  The process relies on PZT films deposited by chemical solution deposition resulting in very good performance and reliability. The films generally displays an e31,f coefficient of -15 C/m2.