Characterization of advanced excimer laser crystallized polysilicon thin film transistors

This work presents electrical and radiation stress as well as transient current analysis results for thin film transistors fabricated using an advanced polysilicon laser crystallization method, termed sequential lateral solidification. The TFTs exhibit excellent device characteristics and parameters such as very high electron mobility, as well as good bias stress endurance, with only a small threshold shift but without appreciable subthreshold swing degradation. The analysis of the drain current transients observed after a gate bias pulsing in the OFF state indicated a peak in their temperature dependence, with a generation freezeout at cryogenic temperatures suggesting good crystal quality. Gamma irradiation of TFTs, particularly in the presence of gate bias, resulted in a negative threshold voltage shift due to positive oxide charge creation and a small subthreshold swing degradation.