We report the fabrication and characterization of tungsten films obtained using a thermal evaporation method. Single phase a-tungsten films were obtained at higher substrate temperatures (520-680 degrees C) than the single phase beta-tungsten films (180-220 degrees C). X-ray spectra show that both the a-tungsten films and the 6-tungsten films are polycrystalline having unusual preferred (200) and (321) orientations, respectively. Poor adhesion was observed when the films were deposited on bare silicon substrate. The adhesion is greatly improved by the introduction of a carbon layer between the film and the substrate. The field emission properties of the a-tungsten films and the B-tungsten films were also examined. The a-tungsten films and beta-tungsten films exhibit turn-on fields at 1.3 and 2.8 V/mu m, respectively. Current densities in the order of 10(-1) mA/cm(2) were observed. These field emission properties are believed to be better or much better than that of both tungsten nanowires and nanorods. The relation between the field emission properties and the film structures is discussed. (c) 2007 American Vacuum Society.