The characteristic of nanoporous SiO2 thin film prepared by sol-gel method with catalyst HF was studied by scanning electron microscopy, Fourier transform infrared, HP analyzer series and ellipsometry. Results showed the incorporation of HF effectively adjusted the pore size and distribution, and lowered the leakage current density and dielectric constant. This might be related to the weak acidity of HF, which properly controlled the velocity of chemical reaction in solution, and to the introduction of strong Si-F bonds, which had the lower electronegative and the larger volume.
