Speaker
Description
Al(X)N substituted with Sc (Al1-xScxN, ASN) is one of the most popular thin film materials for piezoelectric micro-electromechanical system (MEMS) devices. One of the main challenges is to tailor composition and microstructure of ASN to achieve piezoelectric properties suitable for actuator applications.
In this work, we will showcase some approaches to enhance the piezoelectric performance of ASN either by improving the crystal quality or by designing tailored multilayer thin film stacks. In particular, we will show that by employing carefully optimized sputtering processes and suitable buffer layers and electrode designs, Al0.64Sc0.36N multilayer thin films achieve excellent piezoelectric properties, making them a valid alternative to lead-based materials for piezoMEMS. Using a compositionally graded approach, we were also able to tailor the ferroelectric imprint of AlScN thin films, which is relevant to implementation as bimorph actuator or as ferroelectric memory. Furthermore, by employing a mixed experimental-computational approach, we are also exploring alternative AlN-based alloys (e.g. AlYN), which may lead to replacing the critical element Sc, thus enhancing the sustainability and EU strategic autonomy for this class of materials.