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/cm 2 is used to deposit a tungsten film on a SiO 2 substrate in a tungsten hexacarbonyl (W(CO) 6 ) gas environment. The resistivity of the film shows a sharp decrease around a dose of 0.6×10 17 cm -2 , and the resistivity becomes almost constant (at about 120 µΩ·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.