Temperature-dependent transfer characteristics of low turn-on voltage InGaZnO metal-oxide devices with thin titanium oxide capping layers

Hsiao Hsuan Hsu, Chun Hu Cheng, Ping Chiou, Yu Chien Chiu, Shiang Shiou Yen, Chien Hung Tung, Chun Yen Chang

Research output: Contribution to journalArticle

2 Citations (Scopus)


This paper reports an InGaZnO thin-film transistor involving a wide bandgap gate dielectric of ZrO2 and IGZO/TiOx channel stack. According to our experimental results, the IGZO TFT with a thin TiOx channel capping layer shows good device integrity of a low threshold voltage of 0.37 V, a small sub-threshold swing of 77 mV/decade, and a high mobility of 33 cm2/V·s under a low drive voltage of <2V. We also demonstrate that the significantly improved electrical property is mainly contributed by the enhanced channel electric field after TiOx capping, associated with maximizing charge accumulated capability. The favorable high-temperature transfer characteristics are also obtained in IGZO/TiOx TFT, indicating a weak Fermi-level pinning in IGZO/TiOx channel structure. With the operating temperature increasing further, the thermal activated effect shall dominate IGZO channel property beyond percolation conduction.

Original languageEnglish
Article number6894152
Pages (from-to)512-517
Number of pages6
JournalIEEE/OSA Journal of Display Technology
Issue number6
Publication statusPublished - 2015 Jun 1



  • Indium-gallium-zinc oxide (IGZO)
  • thin-film transistor (TFT)
  • titanium oxide (TiO<inf>x</inf>)
  • zirconium oxide (ZrO<inf>2</inf>)

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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