Effect of Annealing and Gate Insulator Material Changing on the Performances of IGZO-TFT

Abstract:

Indium-gallium-zinc oxide Thin Film Transistors (IGZO-TFT) were separately prepared with SiO_x and SiN_x/ SiO_x as gate insulator,with IGZO films deposited at room-temperature by RF magnetron sputtering method as active layer.Compared with TFT with SiO_x as gate insulator, The saturation mobility and the on/off ratio of TFT with SiN_x/ SiO_x as gate insulator were much higher. And,the threshold swing was also smaller.But,the threshold voltage was not good enough,was larger. By annealing at 200°C in the air,the saturation mobility increased from 1.42 to 7.5 cm².V^-1.S^-1. While, the saturation mobility had no obvious change when TFT was annealed at high temperature. Seriously, IGZO annealed at high temperature would become crystal,it was not good for the ohmic contact between active layer and metal conductive layer,and,the interface between active layer and insulator would be deteriorated.These will result in the threshold swing become larger and the on/off ratio get smaller.200°C is a suitable temperature for annealing. So,using SiN_x/ SiO_x films as gate insulator,together with TFT annealing at low temperature, could improve the performances of TFT effectively.

• Periodical: Applied Mechanics and Materials (Volumes 670-671)
• Pages: 1467-1470
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.670-671.1467
• Online since: October 2014
• Authors: Ji Feng Shi*, Long Long Chen, Xiang Sun
• Keywords: Indium-Gallium-Zinc Oxide, Insulator, Thin Film Transistor

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