Compact Modeling of the Transient Carrier Trap/Detrap Characteristics in Polysilicon TFTs

An investigation of the carrier trapping influence on device characteristics in poly-Si thin-film transistors (TFTs) is reported. Particular focus is laid on the transient characteristics, which is influenced by the carrier trapping during the device operation. On the basis of these features, a compact model for TFT-circuit simulation has been developed, which considers the dynamically changing time constant of the carrier trapping in the framework of a complete surface-potential description, thus enabling modeling the dynamically varying trapped carrier density. The compact model is verified against measured characteristics of repeated switching.