2162-8769/2014/3(2)/Q20/4/$31.00 © The Electrochemical Society The Influence of Fluorinated Silicon Nitride Gate Insulator on Positive Bias Stability toward Highly Reliable Amorphous

For gate insulator of amorphous InGaZnO thin-film transistor, we fabricated fluorinated silicon nitride (SiN:F) film formed by an inductively-coupled plasma enhanced chemical vapor deposition method by utilizing SiF4/N2 as source gases. Threshold voltage shift against electrical stress was successfully suppressed. Chemical analysis revealed that the hydrogen concentration was reduced to 1/10 of conventional SiN film and fluorine was introduced into the interface between the SiN:F film and channel layer. We conclude that the decrease of hydrogen content and introduction of fluorine lead to decrease of electron trap density at the interface and/or the SiN:F film. © 2013 The Electrochemical Society. [DOI: 10.1149/2.014402jss] All rights reserved. Manuscript submitted September 30, 2013; revised manuscript received November 6, 2013. Published December 3, 2013. Amorphous In-Ga-Zn-O thin-film transistors (a-IGZO TFTs) have attracted considerable attention as an alternative device for conven-tional amorphous silicon (a-Si) TFTs. The features of this material are a low fabrication temperature less than 200◦C, and preferable electronic properties such as higher field-effect mobility and lower threshold voltage (Vth) compared with those of a-Si TFTs. Such de-sirable performances also enable us to design peripheral circuits fo