On the mechanical and electrical properties of self-assembly-based organosilicate porous films

Abstract

The effect of the replacement of Si–O–Si by Si–CH₂–Si groups on the mechanical and electrical properties of silica-based hybrid sol–gel thin films is reported. For a reliable inference, two sets of organosilica films were synthesized – one consisting of a silica matrix decorated with methyl groups (Si–CH₃) while the other further incorporating bridging methylene (Si–CH₂–Si) functionalities. As a result, at the film density of 0.87 g cm⁻³, a higher Young's modulus of 6.6 GPa was deduced for the film containing Si–CH₂–Si groups compared to 5.3 GPa for the one with Si–O–Si functionalities. Concurrently, the introduction of the methylene bridging groups leads to a dielectric constant increase from 2.12 to 2.27. Furthermore, the type of surfactant, ionic or nonionic, employed as a templating agent has a negligible effect on the electrical properties and the reliability performance of the porous organosilica films.