Structural, electrical and mechanical properties of templated silsesquioxane porous films

Porous dielectric films were successfully synthesized by incorporating poly(amidoamine) (PAMAM) template to silsesquioxane host polymer. The structural, electrical and mechanical properties of the films could be tuned with PAMAM concentration. The porosity of the films increased while the dielectric constant of the films decreased with PAMAM fraction. Films with ultra-low dielectric constant about 2.06 could be obtained with leakage current density on the order of 10−7 A/cm2 at 1 MV/cm. The conduction mechanism was analyzed and showed that the carries in the films followed Schottky mechanism. The mechanical properties of the films were determined with nanoindentation. Both elastic modulus and hardness decreased with PAMAM concentration, suggesting that the incorporation of the porosity to the films compromised their mechanical properties.