The stability of piezoelectric scandium aluminium nitride (Sc_xAl_1-xN) thin films with x= 27% was investigated after post deposition annealings up to 1000°C. The Sc_xAl_1-xN thin films targeted for applications in micro-electromechanical systems (MEMS) were deposited close to room-temperature applying DC magnetron sputtering. Varying deposition parameters yielded films with different microstructural properties and piezoelectric constants. Upon annealing, the crystalline quality of thin films with c-axis orientation increased, as found via characterization techniques such as X-ray diffractometry and fourier transform infrared absorbance measurements. Additionally, piezoelectric constants after annealing steps up to 1000°C are reported as obtained via a Berlincourt measurement principle. Furthermore, modifications in chemical composition during temperature loads up to 1000°C were recorded by thermal effusion measurements.

Date Published: 21 May 2015
PDF: 7 pages
Proc. SPIE 9517, Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems, 95171C (21 May 2015); doi: 10.1117/12.2178503

Published in SPIE Proceedings Vol. 9517:
Smart Sensors, Actuators, and MEMS VII; and Cyber Physical Systems
José Luis Sánchez-Rojas; Riccardo Brama, Editor(s)