This paper describes a research project in which tantalum boride (TaBx) films were deposited on silicon substrates by radio frequency (rf) magnetron sputtering of a TaB2 alloy target. The deposition rate, chemical composition, crystalline microstructure, and sheet resistivity were examined by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, and sheet resistance measurements. The results indicate that the deposition rate, film composition, and microstructure correlate closely with the bias. The deposition mechanism and kinetic model which control the film characteristics are presented here as well. (C) 2003 The Electrochemical Society.