Synergistic approach to high-performance oxide thin film transistors using a bilayer channel architecture

ACS Appl Mater Interfaces. 2013 Aug 28;5(16):7983-8. doi: 10.1021/am402065k. Epub 2013 Aug 7.

Abstract

We report here a bilayer metal oxide thin film transistor concept (bMO TFT) where the channel has the structure: dielectric/semiconducting indium oxide (In2O3) layer/semiconducting indium gallium oxide (IGO) layer. Both semiconducting layers are grown from solution via a low-temperature combustion process. The TFT mobilities of bottom-gate/top-contact bMO TFTs processed at T = 250 °C are ~5tmex larger (~2.6 cm(2)/(V s)) than those of single-layer IGO TFTs (~0.5 cm(2)/(V s)), reaching values comparable to single-layer combustion-processed In2O3 TFTs (~3.2 cm(2)/(V s)). More importantly, and unlike single-layer In2O3 TFTs, the threshold voltage of the bMO TFTs is ~0.0 V, and the current on/off ratio is significantly enhanced to ~1 × 10(8) (vs ~1 × 10(4) for In2O3). The microstructure and morphology of the In2O3/IGO bilayers are analyzed by X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy, revealing the polycrystalline nature of the In2O3 layer and the amorphous nature of the IGO layer. This work demonstrates that solution-processed metal oxides can be implemented in bilayer TFT architectures with significantly enhanced performance.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Gallium / chemistry*
  • Indium / chemistry*
  • Microscopy, Atomic Force
  • Microscopy, Electron, Transmission
  • Photoelectron Spectroscopy
  • Semiconductors*
  • Transistors, Electronic*
  • X-Ray Diffraction
  • Zinc Oxide / chemistry

Substances

  • Indium
  • gallium oxide
  • indium oxide
  • Gallium
  • Zinc Oxide