STRUCTURE, COMPOSITION AND ORDER AT INTERFACES OF CRYSTALLINE OXIDES AND OTHER HIGH-K MATERIALS ON SILICON

High-resolution medium energy ion scattering (MEIS) was used to investigate structure, composition and defects in amorphous and crystalline oxides, and their interface with silicon. Isotopic oxygen reactions were examined in several model high-κ systems, including Hf and Ce oxides, silicates and nitrided silicates as a function of composition, crystallinity and post-deposition annealing conditions. Our results show that for post-growth oxidation of Hf-based films there was extensive O exchange throughout the film which could be suppressed by the addition of SiO2. Under our growth conditions, there was no measurable interfacial SiO2 formation. In contrast Ce silicates exhibit rapid interface growth under similar oxygen exposures. Epitaxial SrTiO3 and Sc2O3 films grown by MBE on Si were studied in different channeling geometries. We show that diffusion of Ti and O during SrTiO3 film growth on Si (001) results in substitution of thin interfacial Sr