Subthreshold conduction in short-channel polycrystalline-silicon thin-film transistors
A model that characterizes the subthreshold regime and the threshold voltage of a short-channel polycrystalline silicon thin-film transistor (poly-Si TFT) is developed and supported experimentally. The subthreshold variations with gate and drain voltages are reported and a stronger drain voltage dependence is observed. The subthreshold swing is calculated and its variation with channel length and doping concentration is studied. The results are compared with the available experimental data and a good match is found. The temperature dependence of subthreshold swing and drain current is also shown. The channel length dependent proposed threshold voltage shows excellent agreement with experimental data.