A dielectric film containing lanthanide 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 Ti, electron beam evaporation
of a lanthanide selected from a group consisting of Nd, Tb, and Dy, and oxidation
of the evaporated Ti/lanthanide film in a Kr/oxygen plasma. The growth rate is
controlled to provide a dielectric film having a lanthanide content ranging from
about five to about forty percent of the dielectric film. These dielectric films
containing lanthanide doped TiOx are amorphous and thermodynamically
stable such that the lanthanide doped TiOx will have minimal reactions
with a silicon substrate or other structures during processing.
