Quasi-single-crystal (001) SrTiO3 templates on Si

The integration of multifunctional oxides on semiconductor devices requires the formation of single-crystal-like oxide templates directly on silicon. We report the fabrication of quasi-single-crystal (001) SrTiO3 templates on (001) Si by annealing 100 nm thick molecular beam epitaxy-grown epitaxial SrTiO3 films at 900 °C. The full width at half maximum of the (002) rocking curve is 0.006°, which is much narrower than SrTiO3 bulk single crystals. An atomically smooth TiO2-terminated surface is obtained by buffered-HF etching, which allows us to create functional oxide heterointerfaces on Si. Epitaxial SrRuO3 thin films grown on the quasi-single-crystal SrTiO3 template exhibit a superior crystalline quality and surface morphology.