Dielectric Characterization of SiO2-PMMA Organic – Inorganic Hybrid Thin Films

Résumé

For the research presented in this paper, hybrid organic-inorganic materials were prepared using a modified sol-gel reaction.
Hybrid organic-inorganic compounds were synthesized in ethanol using methylmethacrylate (MMA), SiO₂ nanoparticles, and 3-trimetoxi-silil-propilmethacrylate (TMSPM) as coupling agent. For the deposition of thin films, the spincoating method was used.
The electrical measurements of dielectric thin films were done using a metalinsulator-metal (MIM) devices fabricated to study the dielectric constant of the films as function of frequency (measured at 1 MHz). Electrical results show a weak trend of the dielectric constant of the hybrid films with different MMA molar ratio. More importantly, the PMMA-SiO₂ hybrid films showed a higher dielectric constant than SiO₂ and PMMA layers, due to the presence of additional C-O-C bond. For the calculation of dielectric permittivity, the thickness of thin films was measured using cross-section SEM micrographs and the value of dielectric permittivity was calculated using electrical capacitance formula.