METALORGANIC CHEMICAL-VAPOR-DEPOSITION OF COPPER FROM COPPER(II) DIMETHYLAMINO ETHOXIDE

Copper metal films were grown on single-crystal strontium titanate (100) by the thermal decomposition of copper dimethylamino ethoxide in inert atmosphere at temperatures between 150 and 270-degrees-C. Films grown at 200-degrees-C are copper metal, free from contaminants, while higher temperatures result in significant carbon and oxygen incorporation. Deposition products were identified by Fourier transform infrared spectroscopic analysis of the reactor gas phase in situ and by mass spectroscopic analysis of the reactor exit gas during deposition. At 200-degrees-C, deposition occurs by interdependent beta-hydride elimination and reductive elimination reactions which produce (dimethylamino)ethanal, (dimethylamino)ethanol, and copper metal. Beta-Hydride and reductive elimination reactions are also dominant at 250-degrees-C; however, the competition of ligand fragmentation reactions with the whole-ligand eliminating reactions leads to carbon and oxygen contamination of the copper metal film.