Microstructural evolution and formation of highly c-axis-oriented aluminum nitride films by reactively magnetron sputtering deposition

AlN films possessing a higher deposition rate to form an amorphous layer in the initial deposition stage will result in the lower deposition rate to form following transition and columnar preferred orientation textures. Therefore, we strongly suggest adopting a two-step deposition method, that is, use lower deposition rate to form preferred orientation layers and then a higher deposition rate to form preferred orientation textures.