A closed-form trapped-charge-included drain current compact model for amorphous oxide semiconductor thin-film transistors. (December 2018) - Yu, Fei
Abstract: A closed-form drain current compact model for amorphous oxide semiconductor (AOS) thin-film transistors (TFTs), including the influence from trapped charges, is presented in this paper. Accounting for both channel and interface trapped charges in this model, we explicitly solve the inherent closed-form surface potential by improving the computational efficiency of the effective charge density approach. Furthermore, based on the explicit solution of the surface potential, the expressions of the trapped and inversion charges in the channel film are derived analytically, and the drain current is integrated from the charge sheet model. Then, for the cases of the different operational voltages, the accuracy and practicability of our model are verified by numerical results of the surface potential and experimental data of the drain current in amorphous In-Ga-Zn-O TFTs, respectively. Finally, we give a discussion about the influence of the interface trapped charges on the device reliability. As a result, the model can be easily to explore the drain current behavior of the AOS TFTs for next-generation display circuit application. Highlights: An inherent closed-form trapped-charge-included drain current compact model of AOS TFTs is derived. The closed-form surface potential without smoothing function is explicitly solved. The drain current is derived from the charge-sheet model and validated by experimental data. Some discussions are gave about the influence from interface trapped charges on the DC properties of AOS TFTs.