The effect of fluorine neutral/ion-beam irradiation to an n-type GaN surface on the ohmic contact property of a Ti/Al/Au multilayer scheme was investigated. The contact formed after a fluorine neutral-beam treatment showed lower contact resistivity than that formed without the treatment and that formed after a fluorine ion-beam treatment. The irradiation of the fluorine neutral beam is believed to create nitrogen vacancies at the surface region of n-GaN due to the preferential removal of nitrogen, which acts as a donor impurity. In addition, the GaN surface treated by the fluorine neutral beam showed less GaFx formation and smaller surface damage compared to the surface treated by the fluorine ion beam. This resulted in lower ohmic contact resistivity. After annealing at temperatures above 600 degrees C, the contact formed after the fluorine neutral-beam treatment exhibited an excellent linear current-voltage characteristic. (c) 2007 The Electrochemical Society.