Effect of Exposure to Ultraviolet-Activated Oxygen on the Electrical Characteristics of Amorphous Indium Gallium Zinc Oxide Thin Film Transistors

An exposure of the back channel of an indium gallium zinc oxide (IGZO) thin film transistor (TFT) to ultraviolet (UV)-activated oxygen can effectively shift the threshold voltage (V-th) of the TFT. The V-th decreases linearly with the exposure time while the on-state current greatly increase with the exposure time. The exposure doesn't have a strong impact on other device parameters. The effect of the exposure on the V-th is attributed to the increase in the electron concentration of the channel layer as a result of the creation of oxygen vacancies by exposure. (C) 2013 The Electrochemical Society.