| Recently, there have been increased efforts toward the facile synthesis of thermally stable metal-organic compounds. Such compounds are well suited for use in the fabrication of microelectronic devices. ZnO is a wide band gap, compound semiconductor exhibiting piezoelectric and optoelectric properties. Simple ligand systems providing clean decomposition are preferable for the synthesis of the metal-complexes that act as ZnO precursors. Herein, the syntheses and characterization of Renaminoesters and the first examples of bis (beta-iminoesterate) Zinc II complexes are reported. The growth of ZnO is also reported.;A series of 25 beta-enaminoesters were synthesized by reaction of the appropriate primary amine with the appropriate t-butyl, methyl or ethyl beta-ketoester in a 1:1 molar ratio. The beta-enaminoesters were isolated as yellow viscous liquids and one low-melting white solid (72 % - 99 % yield, reflux, lh reaction period). Purification via reduced pressure distillation afforded colorless, high-purity oils as determined by standard characterization methods. Metal-Organic Chemical Vapor Deposition (MOCVD) precursors were synthesized by reaction of the free ligands with diethyl zinc in a 2:1 molar ratio respectively. Reactions were carried out under an inert atmosphere of argon or nitrogen using standard Schlenk and vacuum line techniques. The products were isolated as either white solids or viscous liquids and crystallized from pentane affording single crystals that were suitable for X-ray analysis. Further analysis was carried out via 1H-NMR, 13C-NMR, elemental analysis, TGA, and MALDUTOFMS. Analyses revealed homoleptic, monomeric complexes with a tetravalent zinc metal center. Deposition experiments were performed on silicon in a horizontal, hot-walled reactor at atmospheric pressure. The deposited films were analyzed via AFM, XRD and XPS, confirming ZnO. The bis (beta-iminoesterate) zinc II complexes were found to be thermally stable, and in addition provided deposition with low carbon contamination. |
