Surface modified silica mesoporous films as a low dielectric constant intermetal dielectric

Silica mesoporous films with low dielectric constant were successfully fabricated by a multiple-step sol–gel process. Various surface modifications were conducted to make the surface of the films hydrophobicity, which was proved very effective to maintain the low dielectric properties of the films. The basic properties of the silica films were evaluated by atomic force microscopy, specular x-ray reflectivity, Fourier transform infrared, and thermal gravimetric and differential thermal analysis. An inherent low dielectric constant of around 2.0 was realized for about 56% porosity of the silica film with pore size less than 40 nm and the leakage current was at a level of 10−6 A/cm2 after two months of fabrication. Preliminary results of the silica films prepared here present a very positive prospective to intermetal dielectric applications.