A thermal evaporation method was used for the deposition of tungsten films. The tungsten source was resistively heated to a temperature between 1810 and 2010 degrees C for the deposition. The resulting BCC alpha-tungsten film exhibits a rod-like structure and a highly preferred (200) orientation. This unique microstructure leads to field emission properties that are not only superior to the other forms of tungsten but also better than most of the other thin film emitters. A low turn-on field of 1.3 V/mu m and an extremely high field enhanced factor of 398095 were obtained. (c) 2005 Elsevier B.V. All rights reserved.