Theoretical and experimental study of ScAlN/Sapphire structure based SAW sensor

Several SAW devices based on Sc
_0.1
Al
_0.9
N/Sapphire bilayer structures were fabricated using various wavelengths and film thicknesses. The acoustic velocity, electromechanical coupling coefficient and temperature coefficient of frequency (TCF) of each device was then measured and the results were compared with calculations using several sets of elastic, piezoelectric and dielectric constants available in the literature. We have shown that the accuracy of available constants is not enough to permit a reliable optimization and design of SAW devices for signal processing and sensors applications.