Experimental Investigation on the Electrical Properties of a-InGaZnO Thin-Film Transistors Under Total Dose Ionizing Radiation

This work conducts an experimental study on the effects of total-ionizing-dose (TID) on amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. The threshold voltage (V-th) exhibited a negative shift during irradiation, concomitant with a decline in carrier mobility (mu(FE)) and an increase in off-current. The TID-induced H-related traps in the a-IGZO layer not only increase the free carriers but also passivate the oxygen vacancies, leading to a reduction in mu(FE) and on/off characteristics, as evidenced by the X-ray Photoelectron Spectroscopy (XPS) analysis. The irradiation damages on the a-IGZO TFTs were effectively mitigated and recovered through low-temperature (200 degrees C) annealing, as confirmed by low-frequency noise (LFN) analysis. This approach offers a viable strategy for the radiation hardening of a-IGZO TFTs aiming at space applications.