Analytical Physical-Based Drain-Current Model of Amorphous InGaZnO TFTs Accounting for Both Non-Degenerate and Degenerate Conduction

In this letter, we propose a physical-based analytical drain current model for amorphous indium-gallium-zinc oxide thin-film transistors (a-IGZO TFTs). As a key feature, the model accounts for both the non-degenerate and the degenerate conduction regimes, including the contributions of trapped and free charges. These two conduction regimes as well as the trapped and free charges are essential to consistently describe a-IGZO TFTs. The model is compared with both exact numerical calculations and measurements. It is continuous, symmetric, simple, and accurate. The model enables to gain physical insight on the material and device properties, and it is a valuable tool for fast process optimization and circuit design.