Atomic layer deposition of TiO2 films from TiCl4 and H2O was studied a
t reactor temperatures 100-500 degrees C. Amorphous films grew at temp
eratures below 165 degrees C, anatase structure was observed in the fi
lms grown at 165-350 degrees C while rutile dominated in the films obt
ained at temperatures above 350 degrees C. The surface morphology and
optical losses of the films are related to the film structure. The hig
hest surface roughness was observed at the temperature of amorphous to
crystalline phase transition. The smoothest surfaces were recorded fo
r amorphous films. The amorphous films grown at 100 degrees C had opti
cal losses below 100 cm(-1) in the visible range of the spectrum.