Theoretical analysis of ultra low-k porous films with periodic pore arrangement and high elastic modulus

We have demonstrated that the periodicity in pore structure increases the elastic modulus E with maintaining the dielectric constant k by analytical and numerical calculations. The periodic porous silica films having the hexagonal arrangement of circular cylindrical pores with k<2.0 and E>3 GPa is feasible at the porosity of 0.62 with the bulk material of k/sub b/=4.0 and E/sub b/>21 GPa. Calculation results have been confirmed with the experimental data by taking into account the experimental pore shape. The periodic porous silica films having the three-dimensional cubic structure of spherical pores with k<2.0 and E>3GPa is feasible at the porosity of 0.60 using the bulk material of k/sub b/=4.0 and E/sub b/>12 GPa.