Highly Efficient Rapid Annealing of Thin Polar Polymer Film Ferroelectric Devices at Sub-Glass Transition Temperature.

An unexpected rapid anneal of electrically active defects in an ultrathin (15.5 nm) polar polyimide film at and below glass transition temperature ( ) is reported. The polar polymer is the gate dielectric of a thin-film-transistor. Gate leakage current density ( ) through the polymer initially increases with temperature, as expected, but decreases rapidly at - 60 °C. After ≈2 min at , the leakage is reduced by nearly three orders of magnitude. A concomitant observation is that the drain current ( )-gate voltage ( ) hysteresis decreases with temperature, reaching zero at nearly the same temperature at which collapses. As drops further, the drain current hysteresis increases again but in the opposite direction. This combination strongly supports the interpretation of rapid defect annealing.