TY  - CHAP
U1  - Konferenzveröffentlichung
A1  - Feil, Niclas M.
A1  - Mayer, Elena
A1  - Christian, Björn
A1  - Ding, Anli
A1  - Žukauskaitė, Agnė
A1  - Ambacher, Oliver
T1  - Novel Method for Extracting Material Constants of Epitaxial Wurtzite AlScN Films on Sapphire Using Higher Order Surface Acoustic Wave Modes
T2  - 2020 Symposium Proceedings
N2  - Partial substitution of Al atoms with Sc in wurtzite AlN crystals increases the piezoelectric constants. This leads to an increased electromechanical coupling, which is required for high bandwidths in piezo-acoustic filters. The crystal bonds in Ah-xScxN (AlScN) are softened as function of Sc atomic percentage x, leading to reduction of phase velocity in the film. Combining high Sc content AlScN films with high velocity substrates favors higher order guided surface acoustic wave (SAW) modes [1]. This study investigates higher order SAW modes in epitaxial AlScN on sapphire (Al2O3). Their dispersion for Pt metallized epitaxial AlScN films on Al2O3was computed for two different propagation directions. Computed phase velocity dispersion branches were experimentally verified by the characterization of fabricated SAW resonators. The results indicated four wave modes for the propagation direction (0°, 0°, 0°), featuring 3D polarized displacement fields. The sensitivity of the wave modes to the elastic constants of AlScN was investigated. It was shown that due to the 3D polarization of the waves, all elastic constants have an influence on the phase velocity and can be measured by suitable weighting functions in material constant extraction procedures.
Y1  - 2020
SN  - 1948-5727 (digital)
SS  - 1948-5727 (digital)
SN  - 1948-5719 (Print on Demand)
SS  - 1948-5719 (Print on Demand)
SN  - 978-1-7281-5448-0 (digital)
SB  - 978-1-7281-5448-0 (digital)
SN  - 978-1-7281-5449-7 (Print on Demand)
SB  - 978-1-7281-5449-7 (Print on Demand)
U6  - https://doi.org/10.1109/IUS46767.2020.9251767
DO  - https://doi.org/10.1109/IUS46767.2020.9251767
SP  - 4
S1  - 4
PB  - IEEE
ER  -