Method for forming a titanate thin film on silicon, and device formed thereby

摘要

A method for forming a dielectric layer onto a substrate having a silicon surface includes initially depositing an oxidizable metal thin film onto the surface and thereafter depositing a thin film of a metal titanate compound, such as the zirconium titanate. The metal thin film is preferably formed of tantalum, titanium or zirconium. Following deposition of the metal titanate thin film, the metal titanate is annealed by heating in an oxidizing atmosphere at a temperature effective to recrystalize the titanate to increase the dielectric properties. During annealing, the metal film reacts with oxygen to form a metal oxide thin film intermediate the metal titanate thin film and the silicon surface. The oxidation of the metal thin film inhibits oxidation of the underlying silicon that would otherwise reduce the effective capacitance of the dielectric layer. The resulting coated substrate thus includes a dielectric layer that includes a thin film of the oxidized metal and an oxygen-annealed metal titanate thin film and exhibits an increased effective capacitance and improved dielectric properties, particularly in comparison to a comparable oxygen-annealed titanate films formed directly onto silicon surfaces.