Electrical and Statistical Characterization of Reactively Sputtered TiOx Capacitors with Nickel Electrodes

Thin film capacitors were sputtered on Si wafers with Ni electrodes in order to
determine the dielectric properties of reactively sputtered TiOx with a base metal
electrode system. The use of Ni electrodes gave electrically responsive devices with low frequency resistances of 350 to 9100 Ω, permittivities from 250 to 1500, and losses between 0.300 and 0.750. The large loss values have been attributed to the semiconductive nature of sub-stoichiometric TiOx. The decreased resistance is subsequently responsible for the elevated permittivities. Dielectric data was able to be analyzed by a full factorial design of experiments analysis and has been related to the activity of oxygen in the plasma during deposition. XPS characterization confirmed the proposed effects of oxygen both in and on the film during deposition.