Microstructure of titanium dioxide (TiO2) thin films grown in the atomic layer deposition (ALD) process from titanium ethoxide (Ti(OCH2CH3)(4)) and water (H2O) vapor was studied. It was revealed that formation of crystalline (anatase) phase in the films at 200 degreesC and higher substrate temperatures resulted in considerable surface roughening and increase in the growth rate. The effect most markedly contributed to the film growth at 200 degreesC. At this temperature, the average growth rate increased 1.4 times with the increase of film thickness from about 100 to 280 nm.