Enhancement of effective electromechanical coupling factor by mass loading in layered surface acoustic wave device structures
- 9 June 2016
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 55 (7S1) , 07KD07
Abstract
This paper describes a drastic enhancement of the effective coupling factor by mass loading in layered surface acoustic wave (SAW) device structures such as the ScAlN film/Si substrate structure. This phenomenon occurs when the piezoelectric layer exhibits a high acoustic wave velocity. The mass loading decreases the SAW velocity and causes SAW energy confinement close to the top surface where an interdigital transducer is placed. It is shown that this phenomenon is obvious even when an amorphous SiO2 film is deposited on the top surface for temperature compensation. This enhancement was also found in various combinations of electrode, piezoelectric layer, and/or substrate materials. The existence of this phenomenon was verified experimentally using the ScAlN film/Si substrate structure.Keywords
This publication has 27 references indexed in Scilit:
- Elastic constants and critical thicknesses of ScGaN and ScAlNJournal of Applied Physics, 2013
- Piezoelectric Al1−xScxN thin films: A semiconductor compatible solution for mechanical energy harvesting and sensorsApplied Physics Letters, 2013
- Microstructure and dielectric properties of piezoelectric magnetron sputtered w-ScxAl1−xN thin filmsJournal of Applied Physics, 2012
- Electromechanical properties of Al0.9Sc0.1N thin films evaluated at 2.5 GHz film bulk acoustic resonatorsApplied Physics Letters, 2011
- Aluminum scandium nitride thin-film bulk acoustic resonators for wide band applicationsVacuum, 2011
- Increased electromechanical coupling in w−ScxAl1−xNApplied Physics Letters, 2010
- Effects of volume mismatch and electronic structure on the decomposition of ScAlN and TiAlN solid solutionsPhysical Review B, 2010
- Influence of growth temperature and scandium concentration on piezoelectric response of scandium aluminum nitride alloy thin filmsApplied Physics Letters, 2009
- Cubic Sc1−xAlxN solid solution thin films deposited by reactive magnetron sputter epitaxy onto ScN(111)Journal of Applied Physics, 2009
- Enhancement of Piezoelectric Response in Scandium Aluminum Nitride Alloy Thin Films Prepared by Dual Reactive CosputteringAdvanced Materials, 2009