Effects of Nitrogen Doping on Performance of Amorphous SnSiO Thin Film Transistor

Abstract

We investigated the effect of nitrogen flow rate during the sputtering on the performances of tin silicon oxide (TSO) thin film transistors (TFTs) through comparing to the TFTs with different oxygen flow rates. Increasing nitrogen flow rate as well as oxygen flow rate can reduce the carrier concentration and shift turn on voltage to the positive direction, indicating that nitrogen can be a good carrier suppressor of the TSO channel layer. The oxygen vacancies can be filled with nitrogen atoms resulting in less electron donors. Correspondingly, the mobility decreases due to the percolation conduction model. Besides, the TSO channel layer is amorphous regardless of nitrogen flow rate, which is important to ensure uniformity of oxide TFTs.