Anomalous "sweeping stress" induced degradation in n-type low temperature poly-Si thin film transistors

Anomalous "sweeping stress" induced degradation is first observed in n-type metal-induced laterally crystallized low temperature thin film transistors (TFTs). Key stress parameters include the maximum drain bias, the sweeping time and the number of sweeping. Degradation occurs only when the maximum drain bias exceeds a critical value. Both transfer and output characteristic degradation is found much similar to that of hot carrier (HC) degradation. But longer sweeping time causes larger degradation, which is opposite to that in dynamic He degradation. Besides, such degradation can only be observed in low temperature crystallized TFTs. © 2009 IEEE