High mobility InGaZnO thin film transistor using narrow-bandgap titanium-oxide semiconductor as channel capping layer

H. H. Hsu, P. Chiou, Y. C. Chiu, S. S. Yen, C. Y. Chang, C. H. Cheng

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Metal-oxide InGaZnO thin-film transistors (IGZO TFTs) have received substantial attention as potential substitutes for amorphous Si and/or polycrystalline Si in active-matrix liquid-crystal displays, active-matrix organic light emitted diodes (AMOLEDs), and three-dimensional (3D) display applications [1]-[2]. It is well known that the multi-alloy IGZO channel plays an important role in device characteristics such as subthreshold swing (SS) and field-effect mobility (μFE). Although the high-K gate dielectrics to lower operating voltage and threshold voltage (VT) of TFT devices have demonstrated [3]-[5], these critical issues on transfer characteristics still need to be overcome. The large SS and low μFE prevent them from being applied in fast-switching and high-resolution displays. In this paper, we demonstrate high mobility IGZO TFT with titanium oxide (TiO x) channel capping layer. Large μfe of 66 cm 2/Vs and low SS of 79 mV/dec were achieved using narrow-bandgap TiOx (Eg∼ 3.1eV) [6] with optimized 5-nm thickness. The similar bandgap and conduction band offset to those of IGZO are favorable to obtain a low resistance ohmic contact between amorphous IGZO and Al contact metals.

Original languageEnglish
Title of host publication72nd Device Research Conference, DRC 2014 - Conference Digest
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages2
ISBN (Print)9781479954056
Publication statusPublished - 2014
Event72nd Device Research Conference, DRC 2014 - Santa Barbara, CA, United States
Duration: 2014 Jun 222014 Jun 25

Publication series

NameDevice Research Conference - Conference Digest, DRC
ISSN (Print)1548-3770


Other72nd Device Research Conference, DRC 2014
Country/TerritoryUnited States
CitySanta Barbara, CA

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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