New approach for the preparation of nanoporous polyorganosilicate low‐k films

Abstract

The distribution of pores and the mechanical properties of materials are the key factors in preparing satisfactory low-k films. In the present study, a kind of silsesquioxane-polyethylene glycol (SSQ-PEG) was synthesized and used as a template to make the distribution of pores more even in the low-k films. The crosslinking density of films could be adjusted by the sol-gel of tetramethoxysilane/dimethoxydimethylsilane with various proportions. The porosity of films could also be adjusted with different proportions of pendant PEG chains introduced. A dielectric constant as low as 2.1 had been achieved for nanoporous polyorganosilicate films with good tenacity.

Cross-Linkable Molecular Glasses: Low Dielectric Constant Materials Patternable in Hydrofluoroethers

“…In order to reduce the dielectric constant of a material, various approaches have been extensively explored in the past decade − . Because the k values of a material depend upon the density and polarizability, increasing the free volume inside the film and reducing the polarizable moieties are straightforward strategies for material design.…”

“…Lowering density has been studied by introducing pores into the film or appending sterically bulky moieties into the molecular structure. While those porous films successfully provided dielectric constants of down to 1.8 ,, , a loss of mechanical toughness due to the fragile pores during subsequent processing steps remains a significant problem. Materials involving bulky molecular structures seem promising for robust insulating layers, although they tend to be brittle , .…”