Low temperature (150°C) wet oxygen annealing of amorphous InGaZnO thin-film transistors for flexible device applications

Realizing a low temperature annealing process for next-generation, transparent, and flexible displays is necessary. Here, we annealed the channel at different conditions: ultraviolet (UV), ozone (O
3
), wet oxygen (Wet O
2
), and a combination of the two: UV & O
3
, UV & Wet O
2
. Results show that dry ambient UV & O
3
annealing at 150°C has higher mobility (0.36 cm
²
/Vs) and decent subthreshold swing (120 mV/dec) than other dry processes. As for the devices annealed with wet O
2
, the device annealed at 150°C in pure wet O
2
ambient showed the highest mobility at 5 cm
²
/Vs. SIMS measurements were done to measure any changes in the chemical composition found in the a-IGZO bulk to further identify the best annealing condition.