Abstract:

This paper presents a surface-potential-based analytical current and capacitance model of polysilicon thin-film transistors (poly-Si TTs) for circuit simulation , in which the non-iterative numerical algorithm is adopted to calculate the surface potential of poly-Si TFfs as a function of terminal voltage , thus greatly enhancing the efficiency of the proposed model. Based on the analytical calculation of surface potential and the charge sheet approach , the current-voltage model considering both the small geometry effects and the kink effect is developed. Moreover , a charge-based gate capacitance model is derived. It is indicated that the current and capacitance model is continuous and accurate across the linear and saturation regions without any unphysical interpolation scheme. A comparison between the data obtained by the model and those by experiments shows that the results accord well with each other , which verifies the correctness of the proposed model. S0 , it can be concluded that the proposed model is suitable for the incorporation into circuit simulators.

Key words: polysilicon thin-film transistor, surface potential, current model, capacitance model