A Unified Physical-Based Model of Series Resistance of Polycrystalline Silicon Thin-Film Transistors With Explicit Analytical Solutions

A physical-based analytical series resistance (R_s) model is first proposed to accurately evaluate the R_s of polycrystalline silicon thin-film transistors (TFTs). Through carefully analyzing the gate-to-source/drain overlap regions, three underlying physical effects wherein are adequately included, namely the gate (V_g)-induced carrier accumulation, current path spreading, and carrier transport via thermionic emission over grain boundaries. The proposed model can precisely reproduce the V_g dependent R_s behavior and fit the experimental data of both metal-induced lateral crystallized and excimer laser annealed TFTs. Furthermore, an explicit analytical expression of R_s is derived using appropriate approximation, based on which all underlying R_s components and their dependencies on device parameters can be clarified. Finally, feasible approaches of R_s reduction are suggested.