Proposal and examination of new type of TFT with tunneling dielectric film at both ends of channel fabrication area

An important aspect of a thin-film transistor (TFT) is reducing the current flowing between the source and drain when the gate is off. In this research, we proposed a new TFT, the tunneling dielectric TFT (TDTFT), that has a thin dielectric film on both ends of the channel region, and studied its operation through simulations. We calculated the drain current (Ioff) when the gate is off, the drain current–drain voltage characteristic, and the transconductance in the TDTFT. When the thin dielectric film is a 0.5-nm-thick TiO2 film, Ioff of the TDTFT is about six digits less than that of a conventional TFT. We also studied the double silicon on insulator (DSOI) structure which improves the drive power of the TFT even for a thin Si film. When a TDTFT is fabricated on DSOI, simple calculations showed that the on–off ratio was several times better than that of a conventional TFT. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 88(11): 44–53, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10210