Y.-K. Moon, D.-Y. Moon, S. Lee, and J.-W. Park (Korea)
Nanophotonics, zinc oxide, thin film transistor, oxygen
partial pressure, rapid thermal annealing, proton
The object of this study was to improve the performance
of ZnO thin film transistors (TFTs) by the optimal process
such as a controlling of oxygen partial pressure, rapid
thermal annealing (RTA) process, and proton irradiation.
ZnO thin films are deposited as channel layer with
various oxygen partial pressures. After ZnO-TFTs
fabrication, in order to improve the interface
characteristics between source/drain electrodes and the
channel layer, we have conducted the RTA process.
However, the conductivity of the ZnO channel layer was
dramatically increased during the RTA process.
Therefore, the RTA-treated ZnO-TFTs did not show the
proper output and transfer characteristics. In order to
control the electrical properties of the channel layer, we
exposed the RTA-treated ZnO-TFTs to 6.1-MeV proton
irradiation beam energy at fluences from 6.7× 1012
. The conductivity of the ZnO thin film
decreased after high-dose proton irradiation. The field
effective mobility of ZnO-TFTs increased from 1.65
/V-s to 4.12 cm2
/V-s after the RTA and the high dose
proton irradiation. We obtained an enhancement of ZnO
TFT performance using the controlling of oxygen partial
pressure, RTA process, and high-dose proton irradiation.