Evaluation of self-heating and hot carrier degradation of poly-Si thin-film transistors using charge pumping technique

Self-heating (SH) and hot carrier (HC) degradation of n-type poly-Si thin-film transistors (TFTs) is evaluated by using charge pumping (CP) technique. By extracting trap state energy distribution, it is demonstrated that SH degradation is mainly attributed to the generation of deep states. For HC stressed TFTs, an anomalous I_CP decrease with the stress time is observed in a low V_g stress condition controlled by hole trapping; while in a mid V_g condition, CP signal clearly indicates the trap states generation controlled by electron trapping.