Epitaxial growth mechanism of chemical-vapor-deposited anatase on strontium titanate substrate

Abstract

Titanium dioxide films were chemically prepared on (001) single-crystal strontium titanate, SrTiO3, using a vapor deposition apparatus operating under atmospheric pressure with titanium tetra-isopropoxide. At a substrate temperature of 400°C, titanium dioxide grew epitaxially with lateral growth of steps, as well as multinucleation was observed during the initial growth process, i.e., the so-called Stranski-Krastanov growth. As a result, the surface of strontium titanate was completely covered by titanium dioxide steps with an average lateral growth rate of 100 nm/s, followed by multinucleation growth. The nuclei developed in a number of highly oriented crystallites having well defined facets. X-ray diffractometry and transmission electron microscopy revealed that these crystallites consisted of 〈001〉-oriented anatase-type structure.