Two-dimensional device simulation of polysilicon thin film transistors

Electrical characteristics of polysilicon thin-film transistors (poly-Si TFTs) are strongly affected by density of trap states in the energy bandgap. Based on the single exponential deep state density, two-dimensional simulation is used to construct an n-channel poly-Si TFT and simulate its DC and AC characteristics. Subthreshold swing, threshold voltage and gate capacitances are included. Compact models are derived that can describe the unique behaviors of the aforementioned parameters based on the observation of simulation results.