Kinetic study on initial surface reaction of titanium dioxide growth using tetrakis(dimethylamino)titanium and water in atomic layer deposition process: Density functional theory calculation

Abstract

The initial steps in the growth process of atomic layer deposition (ALD) of titanium dioxide at room temperature (RT) were investigated using tetrakis(dimethylamino)titanium (TDMAT) and H2O as the titanium and oxygen sources, respectively, in the adsorption and reaction processes, respectively. Density functional theory at the B3LYP/6-31G(d,p) level was used to calculate the process characteristics. Energy pathways were used to investigate the reaction mechanism in the pre-adsorption, adsorption and reaction steps and the results were compared with other published experimental data. The calculated pathways implied that all the relative energies were located below the reactant levels, indicating the possibility of depositing the TiO2 thin film in ALD at RT. This work kinetically elucidated the agility of the ALD process and identified that the purity of the film could be improved with a temperature increase within a range of low temperatures. The effects were discussed of the levels of the computational method and cluster sizes on the realism of the reaction mechanism.