Laser Ultrasound Investigations of AlScN(0001) and AlScN(11-20) Thin Films Prepared by Magnetron Sputter Epitaxy on Sapphire Substrates.

The laser ultrasound (LU) technique has been used to determine dispersion curves for surface acoustic waves (SAW) propagating in AlScN/AlO systems. Polar and non-polar AlScN thin films were prepared by magnetron sputter epitaxy on AlO substrates and coated with a metal layer. SAW dispersion curves have been measured for various propagation directions on the surface.