Study of a Vanadium Precursor for VO2 Thin-Film Growth in the Atomic Layer Deposition Process by Multiscale Simulations

To develop an effective vanadium precursor for the atomic layer deposition (ALD) of VO 2 thin films on glass, ALD reactions were investigated via a multiscale approach combining density functional theory (DFT) and an off-lattice kinetic Monte Carlo (KMC) model. Tris(dimethylamino) cyclopentadienyl vanadium (CpV(NMe 2 ) 3 ) was designed as a novel precursor and compared with tetrakis(ethylmethylamino) vanadium (TEMAV). DFT was applied to predict the thermal stability and adsorption energy of precursors and ALD reaction pathways for ligand decomposition. The thermal stability of CpV(NMe 2 ) 3 is at a similar level to that of TEMAV, and the ligands of CpV(NMe 2 ) 3 exhibit weaker adsorption than those of TEMAV, implying lower surface contamination. Calculations of energetics during ligand decomposition show that the dominant reaction paths of CpV(NMe 2 ) 3 are more energetically favorable than those of TEMAV, which lead to fast growth of pure film. The off-lattice KMC model was employed to simulate the ALD process with activation energies provided from DFT calculation. KMC simulation shows that CpV(NMe 2 ) 3 produces 6.5% less impurity and leads to 10 3 times faster film growth than the TEMAV. Therefore, it is revealed that the CpV(NMe 2 ) 3 precursor is superior to TEMAV for the ALD process of VO 2 films with low film impurity and high growth rate.