Epitaxial integration of high-mobility La-doped BaSnO3 thin films with silicon.

La-doped BaSnO₃ has been epitaxially integrated with (001) Si using an SrTiO₃ buffer layer via molecular-beam epitaxy (MBE). A 254 nm thick undoped BaSnO₃ buffer layer was grown to enhance the mobility of the overlying La-doped BaSnO₃ layer. The x-ray diffraction rocking curve of the BaSnO₃ 002 peak has a full width at half maximum of 0.02°. At room temperature, the resistivity of the La-doped BaSnO₃ film is 3.6 × 10⁻⁴ Ω cm and the mobility is 128 cm² V⁻¹ s⁻¹ at a carrier concentration of 1.4 × 10²⁰ cm⁻³. These values compare favorably to those of La-doped BaSnO₃ films grown by all techniques other than MBE on single-crystal oxide substrates. Our work opens an exciting arena for integrating hyper-functional oxide electronics that make use of high-mobility oxide films with the workhorse of the semiconductor industry, silicon. [ABSTRACT FROM AUTHOR]