Transparent, well-insulated SiO2 thin films were deposited at room temperature by pulsed laser deposition with a dimethylpolysiloxane target. It could be asserted with confidence that the films deposited at the oxygen gas pressure of 4.4 x 10(-2) Torr were to be SiO2 by X-ray photoelectron spectroscopy (XPS). The XPS analyses also supported that carbon ejected from the target and background oxygen gas interacted to form a carbon-free SiO2 film, though a polymer target was used. However, an excessive oxygen gas pressure such as 4.4 x 10(-1) Tort caused to roughen the surface of the deposited films. Lowering the deposition rate helped to make a dense film and to improve electrical resistivity of the films up to 10(9) Omegam. (C) 2002 Elsevier Science B.V All rights reserved.