AN XPS STUDY OF ZINC-OXIDE THIN-FILM GROWTH ON COPPER USING ZINC ACETATE AS A PRECURSOR

Ultrathin zinc oxide (ZnO) films (10-200 angstrom thickness range) were grown on polycrystalline copper substrates via the sublimation of anhydrous zinc acetate (Zn(CH3COO)2) in high vacuum (5 x 10(-7) mbar). The thermal decomposition of basic zinc acetate precursor films, deposited on room temperature substrates, to ZnO were examined using X-ray photoelectron spectroscopy (XPS). The transformation to ZnO was monitored as a function of post-deposition sample heating, up to temperatures of 350-degrees-C. ZnO films were grown on copper substrates heated to 400-degrees-C and analysed using angle-dependent XPS and depth profiling. These films were found to contain less than 4% atomic carbon in the bulk and there was no direct evidence for island-type growth.