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.