Atomic layer deposition of vanadium oxide thin films from tetrakis(dimethylamino)vanadium precursor

Abstract

Atomic layer deposition (ALD) of vanadium oxide (VO x ) thin films, using tetrakis(dimethylamino)vanadium as the vanadium precursor, is comprehensively reported in this work. The vanadium precursor is highly volatile and can be used at room temperature for deposition. Either H 2 O or O 3 can be used as the coreactant for depositing VO x at 50-200°C. However, partial precursor decomposition is suggested for the deposition temperature higher than 160°C. The as-deposited VO x films are pure, smooth, and amorphous, and can be crystallized into monoclinic VO 2 phase by postdeposition annealing under N 2 ambient. The minimum annealing temperature for film to crystallize is found, by in situ high-temperature X-ray diffraction experiments, at around 550-600°C. In situ quartz crystal microbalance experiments are performed to further analyze the surface reaction mechanism involved in this ALD process.

Atomic layer deposition of vanadium oxides: process and application review

“…It is also worth noting that 150 • C is a common temperature for ALD in all reports regardless of the type of energy input and reactive gas. Figure 6, shows a significantly low sublimation temperature, which confirms high volatility [78]. The TGA analysis features however, a residue with open and closed cups, which is a clear indication of the partial decomposition of the precursor in both cases.…”

“…Amorphous films with mixed +4 and +5 oxidation states of vanadium were obtained. Vanadium oxide films obtained with H 2 O as a reactant had less carbon and nitrogen contamination than films made using O 3 oxidant, [78,79].…”

“…The compound exhibits a monomeric structure in the gas phase [61,62]. Wang et al, [78,79], have reported the thermal ALD of vanadium oxide by implementing the reaction of TDMAV with H 2 O or O 3 . Authors reported that the volatility of the precursor is high enough to allow sublimation at room temperature.…”

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO2 and V2O3 Nanostructures

“…[16] Both oxides are prototype compounds for Mott transition and of significant interest in condensed-matter physics due to their strongly correlated electron system. [17] Vanadium oxide phases have been synthesized by several methods such as sol-gel [18] , pulsed laser deposition [19] , sputtering [20,21] , atomic layer deposition (ALD) [22,23] or chemical vapor deposition (CVD) [24][25][26][27] . The synthesis of VO2 (M1) films by aerosol-assisted and atmospheric pressure CVD has been extensively investigated mainly due to their easy 3 scalability, lower restriction on volatility of the precursors and easy introduction of dopants in films.…”

NiSx@MoS2 heterostructure prepared by atomic layer deposition as high-performance hydrogen evolution reaction electrocatalysts in alkaline media

“…In addition, the composition and microstructure of the heterointerface can be controlled at the atomic level, which is of great importance to obtain a fundamental understanding about the contribution of heterointerfaces to electrocatalytic activities. There have been great progresses recently in developing ALD processes for various transition metal oxides [32,33,34,35,36,37,38,39,40,41,42] and sulfides [30,31,43,44,45,46,47,48,49,50]. Xiong et al [46] designed and constructed a hybrid compound Fe x Co 1Àx S y electrocatalyst with controllable composition on a complex 3D structure (carbon nanotubes on carbon cloths) for HER by ALD.…”