X-ray photoelectron spectroscopy of amorphous AlN alloys prepared by reactive rf sputtering

Thin films of aluminum–nitrogen (AlN) were deposited by radiofrequency sputtering an aluminum target in an N2+H2 atmosphere. The films were deposited on sapphire and Si 〈1 0 0〉 substrates in the ∼50–300 °C temperature range. After deposition the films were investigated by means of optical techniques, X-ray diffraction, and X-ray photoelectron spectroscopy. The substrate temperature exerts great influence on both the sort and number of chemical bonds formed by the Al atoms. The presence of H2 during the film deposition induces changes on the LO phonon in the Al–N bonds in the infrared region. Either the substrate temperature or the presence of hydrogen atoms alters the growth kinetics which determine the main characteristics of the films.