Interactions of copper with oxidized TaSiN

Tantalum rich TaSiN exposed to the ambient results in a homogenous surface composition of a silicon rich Ta Si O x y z mixture. The interaction of sputter deposited copper with oxidized TaSiN OrTaSiN. is investigated using X-ray photoelectron spectroscopy XPS.. Copper is found to wet grow conformally on.OrTaSiN at 300 K. For copper coverages of less 0.4 ML based on the Cu to O atomic ratio., copper is present as Cu I.. At higher coverages, Cu 0. is observed. A change in slope of the copper coverage curve is coincident with the change in copper oxidation state. The data indicate that copper is initially deposited in a conformal ionic layer followed by Cu 0. formation in subsequent depositions. The data also show that although the OrTaSiN surface contains significant amounts of silicon and oxygen, the ability of copper to wet OrTaSiN is superior to that of SiO2. Post-deposition annealing experiments performed indicate that although diffusion does not occur for temperatures less than 900 K, copper ‘‘de-wetting’’ occurs for temperatures above 500 K. q1999 Elsevier Science B.V. All rights reserved.