Formation of TiO_2 thin films by hydrolysis of Ti-tetraethoxide in ethanol: kinetics, surface morphology, constituent phases and their formation mechanism

摘要

titania thin film (≤170 nm in thickness), generally flat, but with a root mean square (RMS) roughness of ～2-3 nm, was deposited on Si(100) substrate by hydrolysis of Ti-tetraethoxide in ethanol at 20 deg. C. Film thickness d (nm) was easily controlled by varying the deposition time t (min): d=142 log(t) -131 (t≥8.4). XRD measurements showed that the as-deposited film was amorphous and that it was transformed to polycrystalline TiO_2 (anatase phase) with 37/100 volume reduction by annealing in air at 350 deg. C.