Method For Epitaxial Growth of (110)-Oriented SrTiO3 Thin Films on Silicon Without Template

Abstract

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 <O OSTYLE="SINGLE"> 1 0 ]/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.