Initial growth mechanism of atomic layer deposited titanium dioxide using cyclopentadienyl-type precursor: A density functional theory study

摘要

The initial reaction mechanism of atomic layer deposited TiO_2 thin film on the silicon surface using Cp~*Ti(OCH_3)_3 as the metal precursor has been investigated by using the density functional theory. We find that Cp~*Ti(OCH_3)_3 adsorbed state can be formed via the hydrogen bonding interaction between CH_3O ligands and the Si- OH sites, which is in good agreement with the quadrupole mass spectrometry (QMS) experimental observations. Moreover, the desorption of adsorbed Cp~*Ti(OCH_3)_3 is favored in the thermodynamic equilibrium state. The elimination reaction of CH_3OH can occur more readily than that of Cp~*H during the Cp~*Ti(OCH_3)_3 pulse. This conclusion is also confirmed by the QMS experimental results.