Basal orientation aluminum nitride grown at low temperature by rf diode sputtering

Abstract

Aluminum nitride films with solely a (0001), or basal crystallographic orientation have been grown on single-crystal silicon and silicon dioxide-coated silicon at substrate temperatures below 100 °C. The deposition technique used was rf diode sputtering of an aluminum target in argon/nitrogen gas mixtures containing 50–100% nitrogen. Unintentional oxygen doping of the growing films was minimized by a target clean-up procedure which was monitored by glow discharge mass spectrometry. X-ray diffraction measurements on the films included relative integrated intensity, peak half width, and precise peak position from which the lattice constant normal to the basal plane was calculated. The preliminary results of a study of the evolution of film crystallography from multiorientation aluminum to single-orientation aluminum nitride as the sputtering gas nitrogen content is increased are also presented.