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

Highly (0 0 2) c-axis-oriented AlN films have been successfully deposited on Ti/Si substrates using reactive magnetron radio frequency (RF) sputtering deposition and ideal AlN films could be obtained by fine-tuning the parameters at pressure 5Pa, temperature of 250 degrees C, and N-2 ratio 85%. The detailed layer-by-layer microstructure of AlN films deposited on Ti/Si substrate consists of TiO2 thin film, amorphous layer without Al2O3 particles, transition layer, and the columnar (0 0 2) e-axis preferred orientation layer. 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. (c) 2004 Elsevier B.V. All rights reserved.