Fig. 1: Lattice parameters and texture of sputtered Al1-xScxN on GaN.

a Lattice parameters a and c of 100-nm-thin Al1-xScxN grown by sputter epitaxy on GaN templates in dependence of Sc content. The black dashed lines correspond to the relaxed a-lattice parameter of AlN and the measured a-lattice parameter of the GaN template. b Corresponding FWHM of the Al1-xScxN 0002 RC in dependence on the Sc content. The values for ferroelectric MOCVD7 and MBE4-grown Al1-xScxN/GaN heterostructures, as well as the FWHM of the 0002 RC of the GaN template (dashed line), are included for comparison.