GROWTH OF TUNGSTEN FILM BY FOCUSED ION-BEAM INDUCED DEPOSITION

Growth of tungsten film by focused-ion-beam (FIB) induced deposition is studied using scanning electron microscope. A 30 kV Ga+ beam with a current density of 14 mA/cm2 is used to deposit a tungsten film on a SiO2 substrate in a tungsten hexacarbonyl (W(CO)6) gas environment. These resistivity of the film shows a sharp decrease around a dose of 0.6 x 10(17) cm-2, and the resistivity becomes almost constant (at about 120-mu-OMEGA . cm) at a larger dose. The film has island structures during the early stages of deposition. The sharp decrease in its resistivity corresponds to coalescence of the islands.