Thermocurable hyperbranched polystyrenes for ultrathin polymer dielectrics.

Thermocurable hyperbranched polystyrenes were successfully synthesized using atom transfer radical polymerization and exhibited superior ultrathin film formation capabilities in comparison with the linear analogues, as assessed by the minimal film thickness attainable by spin-coating without dewetting. They were suitable as ultrathin film organic dielectrics, with parallel plate specific capacitances as high as ∼680 nF/cm2. Similar to high performance inorganic dielectrics, capacitance measurements pointed to the presence of "dead" interfacial capacitance, which could be accounted for by considering the geometric effect of roughness "incommensurability" between metal electrode and polymer film.