Low frequency noise modeling of polycrystalline silicon thin-filmtransistors

摘要

A modified and improved low frequency model for polycrystalline silicon thin-film transistors(poly-Si TFTs) is developed in this paper. For small grain size poly-Si TFTs, based on carrier numberfluctuations, an improvement of the standard low frequency noise model has been investigated to explainthe noise characteristics of poly-Si TFTs. An exponential energy distribution for interface density of statesis employed to model the interface trap capacitance. For large grain size devices, mobility fluctuationsrelated to fluctuations of the grain boundary charges is used to describe the excess subthreshold noise.The anomalous noise increase behavior of poly-Si TFTs when operated in the kink regime is also studiedand modeled. The proposed model and the experimental data agree well over a wide range of operationregimes.