Improved transistor stability against hydrogen by fluorine doping in indium-gallium-zinc-oxide front and back channels

The impact of fluorine (F) doping on the hydrogen stability of indium-gallium-zinc oxide (IGZO) thin-film transistors (TFTs) was systematically investigated. Enhanced hydrogen resistance was achieved by independently introducing F into both the front and back channels of IGZO. The role of F was elucidated by analyzing changes in device characteristics under directional hydrogen exposure, depending on the specific F-doping location. F atoms in IGZO preferentially attract and immobilize incoming hydrogen, effectively mitigating its adverse impact on electrical performance. Notably, even F doping confined to the back channel—remote from the conductive front channel—yielded substantial improvements in stability, while additional doping in the front channel provided further enhancement. These findings experimentally demonstrate that dual-side F-doping in IGZO significantly enhances the hydrogen tolerance of TFTs.