Method for epitaxial growth of (110)-oriented SrTiO₃ thin films on silicon without template

摘要

A process and structure utilizes pulsed laser deposition technique to grow SrTiO₃ (STO) films with single (110) out-of-plane orientation upon a surface of all (100), (110) and (111)-oriented silicon (Si) substrates. No designed buffer layer is needed beneath the STO thin films. The in-plane alignments for the epitaxial STO films grown directly on Si (100) are as STO [001]//Si [001] and STO [1 10]/Si [010]. The SrTiO₃/Si interface is epitaxially crystallized without any amorphous oxide layer. The formation of a coincident site lattice at the interface between Si and a Sr-silicate and/or STO helps to stabilize STO in the epitaxial orientation. The invention can be applied to epitaxial template and barrier for the integration of many other functional oxide materials on silicon. In particular, the (110)-oriented STO structure is useful for practical applications such as the preparation of ferroelectric-insulator-semiconductor devices as well as providing a broad solution to the generic problem of polarity discontinuities at perovskite heterointerfaces.