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.