Fabrication and characterization of Al0.8Sc0.2N piezoelectric thin films

8-inch Al
0.8
Sc
0.2
N piezoelectric thin films were fabricated by RF magnetron sputtering. Soft-etching and AlN buffer layer were used to suppress the appearance of abnormally oriented grains and improve the preferred orientation of films. XRD FWHM of (002) of the film with 1
$\mu \mathrm{m}$
thickness can reach 1.35 < and the roughness is 1.1nm. The Raman shift, refractive index, optical absorption, density, stress, Young's modulus and corrosion resistance of the films were also studied.