Effect of film thickness on the dielectric properties and charge storage in PMMA thin films

In this work, we demonstrate the excellent charge retention capability of spin-coated Polymethylmethacrylate (PMMA) 200 nm thin films previously charged by atomic force microscopy. In order to elucidate the mechanisms involved in the charge transport and charge storage in PMMA films, the conductivity of 200nm thin PMMA films was analyzed on Metal-Insulation-Metal (MIM) structures. A wide range of electric fields was applied on these structures and the charge and discharge currents were recorded. The thermal dependence of the conduction mechanisms was determined for temperatures below the PMMA glass transition temperature. These results were compared to those obtained for 50μm thick PMMA films in which the conductivity appears much smaller. The effects of PMMA thickness on charge transport are discussed.