Epitaxial perovskite thin films grown on silicon by molecular beam epitaxy

Perovskite-type oxide thin films have been grown epitaxially on Si(001) substrates by molecular beam epitaxy (MBE). Reflection high energy electron diffraction (RHEED) and X-ray diffraction (XRD) analysis have demonstrated high quality heteroepitaxy of SrTiO₃ (STO) films with STO[100]//Si[110] and STO(001)//Si(001). Atomic force microscopy (AFM) has revealed atomically smooth STO surface with a 1.2 angstroms rms roughness. Both n- and p-channel metal oxide semiconductor field effect transistors (MOSFET) with epitaxial STO gate dielectric have been fabricated and tested. The leakage current in the devices is over two orders of magnitude lower than an electrically comparable SiO₂ gate dielectric.