Modeling of thin-film transistor device characteristics based on fundamental charge transport physics

Abstract

A model is described that enables the calculation of thin-film transistor (TFT) characteristics starting from fundamental considerations of charge transport. Starting from scattering mechanisms and trap distribution in a semiconductor, electric field and charge density distributions are calculated along the channel length direction. Output and transfer characteristics of a TFT can be calculated at any temperature. The model is quasi-two-dimensional and is based on multiple trap and release transport in the semiconductor active layer. Importantly, the charge transport models that constitute the basis of this paper are very sophisticated and operate at a level of depth and detail that go beyond most other studies on thin-film transistors. Contact resistance effects, often very important in TFTs, are included in the model. Simulation results are presented for several representative TFT dimensions and parameter sets. The model is designed for convenient use by the research community, and the source code as well as instructions are publicly available. The modular nature of the models allows for ease in changing the semiconductor parameters, transport mechanisms, contact barriers, etc.