Ultrathin TiN films were grown by reactive dc magnetron sputtering on thermally oxidized Si (100) substrates. The electrical resistance of the films was monitored in-situ during growth in order to determine the minimum thickness of a continuous film. The coalescence thickness has a minimum of 1 nm at a growth temperature of 400 degrees C after which it increases with growth temperature. The minimum thickness of a continuous film decreases with increasing growth temperature from 2.9 nm at room temperature to 2.2 nm at 650 degrees C. In-situ resistivity measurements show that films grown at 500 degrees C and above are resistant to oxidation indicating high density. X-ray photoelectron spectroscopy and X-ray diffraction measurements show that the TiN grain stoichiometry and grain size increases with increasing growth temperature. (C) 2009 Elsevier B.V. All rights reserved.