Growth of (111)-textured SrTiO3 thin films on Pt(111)/Al2O3(1-102) substrates by rf magnetron sputter deposition

Abstract

SrTiO3 thin films, 20-30nm, with high quality crystal structure and low roughness can be used as growth templates for complex oxides or as the dielectric materials for capacitor structures. In this work, stoichiometric STO thin films were grown by radio frequency magnetron sputtering on Pt (111) templates grown on rAl2O3 substrates, and the effects of growth parameters as well as the underlying Pt templates structural properties on the quality of STO films were studied. A comparison between room temp grown Pt and Pt grown at elevated temps showed that the latter lead to highly ordered Pt and STO films with quasi 2D surface roughness. Xray diffraction showed that the STO thin films had (111) and (222) crystal orientation. A rocking curve full width at half maximum value of 0.2° was achieved, indicating that the STO films are high-quality. The STO films have a roughness less than 1 nm, as measured using atomic force microscopy, comparable to the underlying Pt templates roughness.