Optimization of TiO2 Thin Film Growth at Different Temperatures by Atomic Layer Deposition

Abstract

In this work TiO2 films were grown on silicon substrates by atomic layer deposition (ALD) using TiCl4 and H2O as precursors. The effect of precursor pulse length and reaction temperature on the film growth rate and film uniformity was studied. The film thickness and refractive indices were measured by ellipsometry.

The simulation of TiO2 growth with different TiCl4 pulsing lengths was carried out. The results indicated that in an appropriate temperature range the growth rate and the uniformity are insensitive to a longer pulsing length.

In the temperature optimization experiment, TiO2 films with a small thickness variation of 1% - 4% and growth rate (0.4 Å - 0.5 Å/cycle) were obtained in the temperature range of 200 °C to 300 °C.