Abstract
Reliable integration of a nanostructured piezoelectric thin film into silicon-based microsystems on an industrial scale is a key enabling technology for a wide range of future products. However, the availability of high performance piezoelectric thin films is low and current knowledge in the field is mostly limited to the conditions and scale of academic laboratories. To enhance industrial take-up new industrial standards had to be developed. As of today the known processes for deposition of thin PZT films on silicon are not suitable for high volume production. SINTEF and partners will develop high volume deposition, characterization and integration processes for piezoelectric thin films in the new FP7 project, piezoVolume. The process will ultimately be available on 200 mm wafers with a deposition speed of 3-4 wafers/h*µm from commercial providers. SINTEF is currently a competence centre for piezoMEMS in Europe and using the moveMEMS process in fabrication of devices. To demonstrate the capability of the SINTEF moveMEMS piezoMEMS process (www.microbuilder.org) for fabrication of devices, a multi-project wafer design based on silicon on insulator (SOI) technology was fabricated. Components such as; ultrasonic transducer arrays, accelerometers, ultrasonic microphones, acoustic gas sensors, energy harvesters, micro pumps and actuators for micro-optical mirrors were made to test the feasibility of the piezoMEMS process and technology. The functional piezoelectric material is a thin film of lead zirconate titanate (PZT) deposited by a state-of-the-art chemical solution deposition (CSD) procedure providing a record high effective transversal piezoelectric coefficient of -15 C/m2. Design, fabrication and testing of the packaged devices will be presented in addition to the possibilities within the moveMEMS process.
