In order to fabricate an electronic device, we have optimized growth conditions of VO2 films on amorphous SiO2/Si structure substrates by pulsed laser deposition. The phase of VO2 films observed consisted of multiphases such as VO2, V2O5, and V2O3. The correlation between phase changes and growth conditions of VO2 films was analyzed. Also, the electrical characteristics of VO2-based three terminal devices, attributed to structural and phase changes, are discussed. VO2 films under optimal growth conditions have a change in resistivity of the order of 10(2) near a critical temperature, T-c=340 K. Furthermore, an abrupt jump in current was observed when an electric field was applied to the three terminal device in the VO2-based SiO2/Si structure. The source-drain voltage, in which the abrupt current jump occurred, changed with application of a gate electric field. (C) 2004 American Institute of Physics.