Highly Reliable Multiple-Channel IGZO Thin-Film Transistors Employing Asymmetric Spacing and Channel Width

We designed and fabricated highly reliable multiple-channel indium-gallium-zinc oxide (IGZO) thin-film transistors (TFTs) without any additional fabrication processes. We also investigated the geometric factors of the multiple-channel structure that influence the reliability of the IGZO TFTs in high saturation mode, such as the spacing and width of the subchannels. The proposed device exhibited superior reliability $(\Delta V_{\rm TH}~< ~0.2~{\rm V)}$ due to the larger spacing in the central part of the IGZO channel region, whereas the TFTs with the conventional structure showed a 3 V $\Delta V_{\rm TH}$ shift. This is due to the more effective emission of heat induced inside the TFTs during operation.