Thin films of Ti-Si-N were deposited by plasma-enhanced atomic layer deposition (PEALD) using TiCl4, SiH4, and N-2 /H-2 /Ar radicals at 350degreesC. When the reactants were supplied in the sequence of TiCl4 pulse, SiH4 pulse, then N-2 /H-2 /Ar plasma, the thickness per cycle and Si content in Ti-Si-N thin film saturated at 0.73 Angstrom/cycle and 8.5 atom % (Cl less than or equal to 0.5 atom %), respectively. The thickness per cycle is different from that of metallorganic ALD (MOALD). Although X-ray diffraction did not detect the presence of silicon nitride, the silicon nitride phase was investigated by electron spectroscopy for chemical analysis. The addition of Si in Ti-Si-N thin films results in increased resistivity (approximately 500 muOmega cm) and improved Cu diffusion barrier properties due to the Si3N4 phase. (C) 2004 The Electrochemical Society.