Silicon oxide formation was studied by a novel liquid phase deposition (LPD) method with H2O addition only at 35-degrees-C. The deposition rate could be controlled by varying the quantity of H2O added. The LPD-oxide was lightly oxygen-deficient. FTIR spectra and AES depth profiles indicate that a small amount of fluorine was incorporated into the oxide. The composition of LPD-oxide can be represented as SiO2-xFx. The physicochemical properties of LPD oxide were investigated, as was the behavior of fluorine in the oxide and the chemical reaction. A model for the LPD mechanism is proposed that satisfactorily explains all of the experimental phenomena observed.