Effect of hot carrier stress on the performance, trap densities and transient behavior of SLS ELA TFTs

The effects of DC hot carrier stressing on the device parameters, the active layer trap densities and the carrier generation-trapping characteristics, as deduced from the transient drain current, for thin film transistors fabricated in polysilicon films crystallized using the advanced SLS ELA process are investigated. Both the total grain boundary trap density and the midgap trap density are found to degrade faster for TFTs in thicker films, with devices in ultra-thin films showing almost no trap generation. The application of HCS significantly affected the drain current transients, indicating the introduction of additional defects in the active layer that affect the carrier recombination process.