(163ay) Computational Study of Zno Deposition from Diethylzinc and Water in Metal Organic Chemical Vapor Deposition

A computational study of the gas-phase decomposition of diethylzinc, a common precursor for deposition of Zn-VI compounds, was performed. Density Functional Theory (DFT) was used to describe the bond dissociation behavior of Zn(C2H5)2 using the model-chemistry B3LYP/6-311G(d) to estimate the geometry of this precursor and, expected products. The Raman active vibrational frequencies of Zn(C2H5)2 and product species were also calculated. Raman scattering experiments in a flow-cell provided evidence for Zn-C bond cleavage by both ß-hydride elimination and homolytic fission mechanisms. Additional computational studies were then pursued to better understand reactions between anticipated Zn-containing species produced by diethylzinc pyrolysis (i.e. Zn(C2H5)2, HZnC2H5, and (Zn(C2H5)2)2) and water. The B3LYP/6-311G(d) model chemistry was also used to optimize geometries, estimate thermodynamic properties, and compare likely reaction pathways. The calculations indicate that dihydroxozinc (Zn(OH)2) is the most probable gas phase reaction product near to the substrate. Therefore, various calculations have been perfomed to find how this molecule interact each other to from in wurtzite structure ZnO film and trimerization of three dihydroxozinc molecules was suggested as a likely mechanism.