Reactively rf magnetron sputtered AlN films as gate dielectric

Abstract

AlN films were deposited on silicon (100, 111), fused quartz and GaAs (100) by sputtering in an Ar:N2 gas mixture. We report on the physical and chemical analysis of the films with the aid of scanning electron microscopy, x-ray diffraction, and Auger electron spectroscopy. The films were found to be transparent with a c-axis orientation. Their bulk resistivity was 1015 Ω-cm. Quasistatic C-V analysis of Al/AlN/Si gave a flat-band voltage of 0.85 V, density of fixed charge of 6×1010 cm−2 and a density of fast interface charge of 1.5×1011 cm−2 eV−1 at midgap. These films were formed at 250 °C and offer an attractive fabrication alternative for gate dielectric.