TY  - JOUR
U1  - Wissenschaftlicher Artikel
A1  - Mayer, Elena
A1  - Rogall, Olga
A1  - Ding, Anli
A1  - Nair, Akash
A1  - Žukauskaitė, Agnė
A1  - Pupyrev, Pavel Dmitrievich
A1  - Lomonosov, Alexey M.
A1  - Mayer, Andreas
ED  - Joshi-Imre, Alexandra
T1  - Laser Ultrasound Investigations of AlScN(0001) and AlScN(11-20) Thin Films Prepared by Magnetron Sputter Epitaxy on Sapphire Substrates
JF  - Micromachines
N2  - The laser ultrasound (LU) technique has been used to determine dispersion curves for surface acoustic waves (SAW) propagating in AlScN/Al2O3 systems. Polar and non-polar Al0.77Sc0.23N thin films were prepared by magnetron sputter epitaxy on Al2O3 substrates and coated with a metal layer. SAW dispersion curves have been measured for various propagation directions on the surface. This is easily achieved in LU measurements since no additional surface structures need to be fabricated, which would be required if elastic properties are determined with the help of SAW resonators. Variation of the propagation direction allows for efficient use of the system’s anisotropy when extracting information on elastic properties. This helps to overcome the complexity caused by a large number of elastic constants in the film material. An analysis of the sensitivity of the SAW phase velocities (with respect to the elastic moduli and their dependence on SAW propagation direction) reveals that the non-polar AlScN films are particularly well suited for the extraction of elastic film properties. Good agreement is found between experiment and theoretical predictions, validating LU as a non-destructive and fast technique for the determination of elastic constants of piezoelectric thin films.
KW  - laser ultrasound
KW  - AlScN
KW  - surface acoustic waves
KW  - magnetron sputter epitaxy
KW  - elastic properties
KW  - thin films
Y1  - 2022
UN  - https://nbn-resolving.org/urn:nbn:de:bsz:ofb1-opus4-62107
SN  - 2072-666X
SS  - 2072-666X
U6  - https://doi.org/10.3390/mi13101698
DO  - https://doi.org/10.3390/mi13101698
VL  - 13
IS  - 10
SP  - 1
EP  - 17
PB  - MDPI
CY  - Basel
ER  -