Synthesis and characterization of nanosized titanium oxide films on the (0001) α-Al 2O 3 surface

Abstract

Titanium oxide thin films on the (0001) α-Al 2O 3 surface were synthesized by the method of molecular layering. Atomic force microscopy analysis showed changes in surface morphology when titanium oxide film was formed. On the clean surface of substrate there were only ‘macrosize” features with dimensions of 40–100 nm in the plane of the surface and 1.5–2 nm in height, whereas after the first cycle of synthesis a ‘nanoroughening’ with a height of 0.4–0.8 nm appeared. Dimensions of ‘nanorelief’ elements were in the range of 1–10 nm. During next cycles of synthesis a decreasing of nanorelief height was observed. The film thickness estimated by the ellipsometry measurements as a function of the synthesis cycle number was obtained. The increase in the film thickness per growth cycle was 0.25 nm. The model of fitanium oxide film growth on (0001) α-Al 2O 3 surface was identified by means of angle-resolved X-ray photoelectron spectroscopy investigation.