Fluorine can be naturally incorporated into the silicon oxide (SiO2−xFx) prepared by the liquid phase deposition (LPD) method at 35 °C. Fourier transform infrared and x‐ray photoelectron spectroscopy spectra show that an annealing treatment can change its bond‐structure. Changes in properties accompanying the restructuring are also observed. The annealing also densifies the LPD oxide and reduces its thickness because Si–F intensity decreases and the Si–O–Si intensity increases as annealing temperature increases. ©1995 American Institute of Physics.