Gamma-Ray Irradiation Effect on Sol-Gel Derived Zinc Tin Oxide Thin Film Transistors*

Radiation-hard electronics have broad celestial applications. Zinc tin oxide (ZTO) has a wide band gap of 3.35 eV and is a promising candidate for radiation-hard electronics. The thin film transistors (TFTs) with sol-gel derived ZTO channel layers were fabricated. The effects of gamma-ray irradiation on the ZTO TFTs were investigated using dosages 10 MRad and 50 MRad. The transistor output and transfer characteristics indicated no statistically significant changes before and after irradiation. 10 MRad gamma-irradiation showed a small negative shift while 50 MRad gamma-irradiation showed a small positive shift in the threshold voltage. The maximum drain current (I_D) extracted from the transfer characteristics of the linear region showed negligible change after irradiation at any of the two dosages. A slight reduction in the field effect mobility was observed after 50 MRad irradiation. The overall result suggests radiation-hard and stable nature of the sol-gel derived ZTO TFTs under gamma-ray irradiation. Further analysis is in progress.