Defect Reconfiguration through Surface Functionalization by Galvanic Peeling Treatment for Reliable and Robust InGaZnO TFTs

We propose a galvanic peeling treatment (GPT) process for amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs), enabling selective defect reconfiguration without inducing crystallization or phase separation, through the dissociation of metal–oxygen bonding and densification of the oxide thin-film network. The electron-driven cleavage of weak metal–oxygen bonds (i.e., Zn–OH) not only eliminates unstable Zn sites but also promotes the reinforcement of In–O coordination, thereby improving the structural robustness of the film. The GPT-treated TFTs exhibit significantly enhanced electrical characteristics, with the optimized 10 min process showing an increase in field-effect mobility from 8.4 to 13.1 cm 2 /V·s, a reduced subthreshold swing from 0.28 to 0.24 V/dec More importantly, the improved film density (from 6.5 to 7.2 g/cm 3 ) and reduced optical bandgap fluctuation were directly correlated with suppressed device-to-device variation, demonstrating excellent reproducibility and markedly improved reliability. Under current-illumination stress (CiS) and negative bias temperature illumination stress (NBTiS), the threshold voltage shift was markedly reduced from 829 to 32 mV and from −5.06 to −2.84 V, respectively, while GPT-treated TFTs maintained minimal threshold voltage shift (Δ V TH ) and stable subthreshold slopes in sharp contrast to the pronounced degradation observed in pristine a-IGZO devices after 11 hours.