Piezoelectric thin films, key materials for micro and communication technology

After 20 to 40 years in research and development, micro devices based on piezoelectric thin films have conquered several markets such as RF filters for mobile phones and high-resolution ink jet printing. Many more are in the emerging state. Finally, the advantages of piezoelectric coupling in electro-mechanical problems have become evident for a growing community of microsystems engineers.  This talk will first give an overview on the field including own works. The challenges in thin film growth of PZT and AlN-ScN alloys are outlined, before taking the focus on applications at RF frequencies in the lower GHz range as used in mobile communication for signal transmission. This is a particularly fruitful and important application field as sound waves at these high frequencies are trapped within a few micrometers, allowing for about 100 times smaller resonators as compared to trapping the electromagnetic wave directly. In addition, the acoustic quality of selected piezoelectric materials is so high, that there is no competition by other principles. The new microsonics technology is essential for smart phones and 5G networks. Beyond communication, numerous sensor applications are studied. Presently, these include also self-powered, wireless sensor nodes.  
Bio: Paul Muralt is honorary professor at the Swiss Federal Institute of Technology EPFL at Lausanne, Switzerland. He made his PhD on incommensurate phase transitions at the Institute of Solid State Physics of ETH Zürich (1984). In his professional career he was working at the IBM Research Laboratory in Zurich, where he pioneered electric surface potential mapping by an STM technique, at the Free University of Berlin, and in a thin film coating industry (Balzers) before joining the Ceramics Laboratory of the Materials Science Institute of EPFL in 1993. He was leading a group on electroceramic thin films for micro and nano technology. He is particularly known for his works in processing, functional characterization and MEMS applications of piezoelectric and pyroelectric thin films such as PbZrTiO₃, AlN and AlScN. He authored or co-authored over 250 scientific articles, which collected 16’000 citations so far. He was teaching thin film deposition, micro and nano structuration, surface analysis and introduction to ceramics. He is IEEE Fellow, received the outstanding achievement award of the International Symposium of Integrated Ferroelectrics in 2005, and the C.B. Sawyer award for innovations in materials from the IEEE International Frequency Control Symposium in 2016. He acted as co-chair of the MRS spring meeting in 2008, and in 2019 he was chair of a large joint meeting in Lausanne including the IEEE International Symposium on Applications of Ferroelectrics.

Program:

• Introduction from Prof. Harm-Anton Klok, Institute of Materials Science and Engineering Director
• Honorary Lecture from Prof. Paul Muralt - "Piezoelectric thin films, key materials for micro and communication technology"