Improvement of Electrical Properties and Bias Stability of InGaZnO Thin-Film Transistors by Fluorinated Silicon Nitride Passivation
Bottom-gate IGZO TFT with SiOX etch-stopper was used for this experiment, and a SiOX or SiNX:F was deposited on the TFT as a passivation . The experimental transfer characteristics (IDS-VGS) of the IGZO TFTs with SiOX and SiNX:F passivation are shown in Fig. 1(a) and 1(b), respectively. The IGZO TFT with SiNX:F passivation showed steep subthrehold swing, low threshold voltage (Vth), and small hysteresis as compared with the SiOX passivation. Fig. 2 shows the comparison of positive bias temperature stress (PBTS) reliability of the IGZO TFTs with SiOX and SiNX:F passivation. It was found that positive threshold voltage shift is significantly suppressed by SiNX:F passivation. Influence of SiNX:F passivation on reliability of the IGZO TFT will be presented at the conference.
Authors would like to thank Tokyo Electron Co., Ltd. for their experimental supports on SiNx:F film.
 K. Nomura, H. Ohta, A. Takagi, T. Kamiya, M. Hirano, and H. Hosono, Nature. 432, 488 (2004).