Preparation and Properties of Aluminum Oxide Films Obtained by Glow Discharge Technique

Abstract

Amorphous aluminum oxide films have been deposited on silicon substrates by decomposing aluminum trichloride in an rf induced glow discharge of oxygen. Among various deposition parameters, it is shown that the reactant gas pressures affect greatly the deposition rate and the resultant film quality. The properties of these films such as infrared transmission, etch rate, film structure, resistivity, dielectric constant, and dielectric strength are described. Aluminum‐aluminum oxide‐silicon (MAS) structures were prepared and characterized by the positive values of flat band voltage, distortion of C‐V curves, and a large, positive shift in flat band voltage under negative bias at an elevated temperature. The field effect electron mobility was as low as 70 cm2/V · sec, while it could be improved by the annealing at around 700°C, or by putting a thin layer of thermally oxidized silicon dioxide between the aluminum oxide and the silicon.