MBE Grown AlN Films on SiC for Piezoelectric MEMS Sensors

Abstract

AbstractMiniaturized piezoelectric sensors based on Microelectromechanical Systems (MEMS) offer the advantages of reduced size, reduced power consumption, increased sensitivity coupled with the ability to form compact multi-sensor arrays. Fabrication of such sensors from single crystal materials further insure more highly reproducible and stable devices with improved performance. In this paper, we describe the integration of MBE grown AlN films onto photoelectrochemically machined SiC microcantilevers and membranes. AlN exhibits excellent piezoelectric properties, including an electromechanical coupling coefficient of 0.088 and a high in-plane acoustic velocity (∼5700m/sec) as well as excellent thermal-mechanical compatibility with SiC. The fabrication of AlN-SiC-based microresonators and flexural plate wave devices, and their application to chemical, biological and fluid sensing, are reported.