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

Abstract

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.

Atomic layer deposition of vanadium oxides: process and application review

“…Alkylamide compounds Vanadium (IV) amide complexes are volatile, reactive, produce noncorrosive by-products, and leave marginal impurities in the films, [58]. Alkylamide compounds with higher molec-ular weight decompose at higher temperatures due to the steric hindrance, [59,60]. Ethylamide compound have e.g.…”

Atomic Layer Deposition of V1–xMoxO2 Thin Films, Largely Enhanced Luminous Transmittance, Solar Modulation

“…Several studies have been systematically reported using ALD technique to deposit VO 2 thin films. , However, to our knowledge, doped VO 2 films by ALD process have not been reported yet. To deposit Mo-doped VO 2 film by ALD nanolamination method, one prerequisite is that the reactor temperature should meet the requirement of the deposition temperature for both VO 2 and MoO 3 .…”

Preparation of porous Mo-doped VO2 films via atomic layer deposition and post annealing

“…9,10) Common methods for depositing VO 2 and doped VO 2 films are reactive sputtering, 11) chemical vapor deposition (CVD), 12) pulsed laser deposition (PLD), 13) and atomic layer deposition (ALD). 14,15) Among them, ALD is a state-of-the-art deposition method for the fabrication of dense metal oxide films with ultrasmooth surfaces and pin-hole-free textures. 16) However, the ALD method is seldom used to deposit porous films.…”