High mobility thin film transistors fabricated on a plastic substrate at a processing temperature of 110°C

We present results from excimer laser processed poly-silicon thin film transistors fabricated on a plastic substrate. Except for the temperature rise during excimer laser irradiation for crystallization, the highest processing temperature that the substrate was subjected to was 110 degrees C. Transistor field-effect mobility of 250 cm(2)/V.s and sub-threshold swing of 0.16 V/decade were measured in these devices. These are the best characteristics reported to date for a thin film transistor (TFT) on a plastic substrate. The performance is attributed to our optimized laser crystallization process of helium sputtered Si films, laser-assisted low-temperature doping processes, and transient annealing.