Improved Crystal Quality of C-Axis Oriented AlN Films With ZnO Buffer Layer

In order to improve the crystal quality of AlN films grown on Si substrate, ZnO buffer layers with different thickness (20, 40, 60, 80, 160 nm) were introduced. The structure, elemental composition, crystalline orientation and surface morphology of AlN/ZnO films were studied in this paper. The results show that ZnO buffer layer improves the crystal quality of AlN films and the optimal thickness of ZnO buffer layer is 60 nm, which yields the best c-axis orientation, uniform grain size and obvious columnar growth. This work makes AlN films on Si substrate more helpful for the preparation of SAW devices.