Effects of terrace formation of SrTiO3 (111) on the growth characteristics of epitaxial Bi4-x, LaxTi(3)O(12) thin films

Abstract

For applications such as non-volatile FRAM, atomic-scale smooth surface of the substrate is necessarily prerequisite to realize epitaxial film growth resulting in sharp interface and high quality film. The objective of this article is to fabricate the SrTiO3 (STO) (I 11) substrate with well defined terrace structure and finally to evaluate the effecs of terrace on the growth of epitaxial Bi4-xLaxTi3O12 (BLT) thin films. Buffered FIT (BOE) solution was successfully applied to terrace formation of STO (111). Compared with BLT films grown on as-received substrate, BLT films on the substrate with well-defined terrace revealed apparently much better surface roughness and coherent interface between BLT film and STO (I 11) substrate. In addition, the c-axis of the BLT film was aligned identically with the STO [001] direction by applying terrace structure. Therefore, step-terrace structure is a crucial factor for the determinination of the structural properties of epitaxial BLT films.