Phase transition during heat treatment in TiO$_2$ films prepared by atomic layer deposition

The process of obtaining a thin TiO$_2$ film on a silicon substrate using atomic layer deposition is described. The study investigates the phase transition in these films from the anatase to rutile polymorphs under various heat treatment conditions. Raman spectroscopy, X-ray diffraction, and atomic force microscopy are used to analyze the structural changes and surface morphology of the films before and after thermal treatment. Analytical data confirm that the anatase TiO$_2$ polymorph grows during thermal atomic layer deposition using titanium tetra-isopropoxide and water as precursors, resulting in a polycrystalline film. During thermal treatment, a complete transition from anatase to rutile for a 1.5 $\mu$m thick film on a silicon substrate occurs after 2 to 3 hours at 1000$^\circ$C.