TaCxNy film was deposited with plasma-enhanced atomic layer deposition using tert-butylimido[tri-diethylamido]tantalum and methane/hydrogen reactive gas mixture. The effect of the methane concentration in the gas mixture on the film property was studied. The resistivity was the lowest at 360 mu Omega cm with 1.5 mol % methane due to the increase in the TaC conducting phase and with over 2.5 mol %, the resistivity was increased due to the incorporation of free carbon. The work function of the film was measured from the metal-oxide-semiconductor structure with a slanted oxide layer. With the introduction of 1.5-2.5% methane, the TaCxNy film with lower work function could be obtained. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3490413] All rights reserved.