Theoretical Investigation of Dielectric Constant and Elastic Modulus of Three-Dimensional Isotropic Porous Silica Films with Cubic and Disordered Pore Arrangements

The dielectric constant (k) and elastic modulus (E) of self-assembled three-dimensional porous silica films were investigated by analytical and numerical calculations to reveal the relationship between k and E. It was found that cubic pore arrangements have E values higher than those of random pore arrangements and two-dimensional periodic hexagonal pore arrangements for the same k. It was also found that disordered isotropic porous silica films having cylindrical pores with well-controlled pore size distributions exhibit an E vs k relationship similar to that of two-dimensional hexagonal periodic porous silica films. The elastic modulus of the skeletal silica was determined to be 40 GPa from the combination of the calculated results and experimental data on ultralow-k disordered porous silica film with a k value of 2.0 and a modulus of 8 GPa.