US Patent 7235854 Lanthanide doped TiO

A dielectric film containing lanthamide doped TiOx and a method of fabricating such a dielectric film produce a reliable gate dielectric having an equivalent oxide thickness thinner than attainable using SiO2. A dielectric film is formed by ion assisted electron beam evaporation of TiO2 and electron beam evaporation of a lanthamide selected from a group consisting of Nd, Tb, and Dy. The growth rate is controlled to provide a dielectric film having a lanthamide content ranging from about ten to about thirty percent of the dielectric film. These dielectric films containing lanthamide doped TiOx are amorphous and thermodynamically stable such that the lanthamide doped TiOx will have minimal reactions with a silicon substrate or other structures during processing.