Growth and properties of nanostructured titanium dioxide deposited by supersonic plasma jet deposition

Titanium dioxide (TiO2) is a wide gap semiconductor suitable for many applications. In this work, TiO2 nanostructured thin films are deposited by a plasma assisted supersonic deposition technique on silicon and on conductive glass substrates. Optical Emission Spectroscopy (OES) is used to monitor plasma conditions and precursor dissociation reactions. The influence of deposition parameters on TiO2 structure, uniformity, grain size, and optical properties are investigated by atomic force microscopy (AFM), mechanical profilometer, scanning electron microscopy (SEM) and spectroscopic ellipsometry (SE). Experimental results show how employed technique allows obtaining uniform films, with a tunable deposition range. Grains size could be chosen varying precursor flux during the deposition process. Films nanostructure and porosity result to be affected by grains size. Substrate roughness results to affect film morphology.