A statistical model to predict the performance variation of polysilicon TFTs formed by grain-enhancement technology

A statistical model to predict grain boundary distribution in the channel of a polysilicon thin-film transistor (TFT) is proposed. The model is valid for arbitrary transistor size to grain size ratio, and is particularly useful to predict the grain boundary distribution of recrystallized large-grain polysilicon TFTs where the transistor size is comparable to the grain size and gives significant device-to-device variation. The model has been extensively verified by comparing it with statistical data obtained from TFTs fabricated using metal-induced-lateral-crystallization and regular solid-phase epitaxial techniques. Good agreements between the experimental results and model prediction are demonstrated.