Improved bias stress stability of In-Ga-Zn-O thin film transistors by UV-ozone treatments of channel/dielectric interfaces

Min Jung Lee, Tae Il Lee, Joong Hwee Cho, Woong Lee, Jae Min Myoung

Research output: Contribution to journalArticle

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Possibility of improving the bias stress stability of amorphous In-Ga-Zn-O thin film transistors (a-IGZO TFTs) was explored by irradiating the channel/dielectric interface with ultraviolet (UV) light during the device fabrication process. The UV treatment of the channel/dielectric interface did not cause significant changes in the device performance itself. However, when the TFTs were tested under prolonged gate bias stress, the device with longest UV treatment showed the smallest time dependence of threshold voltage shift. This accompanied the smallest changes in the field effect mobility and subthreshold swing with extended bias stress. Such improvements in bias stress stability are attributed to the modification of the channel/dielectric interface due to the UV-generated ozone that in turn decreased the interface trap density and structurally modified the interface region on the dielectric side to prevent the redistribution of the trapped charges.

Original languageEnglish
Pages (from-to)469-475
Number of pages7
JournalMaterials Science in Semiconductor Processing
Publication statusPublished - 2015 Feb


All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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