Effects of SF 6 Plasma Treatment Time on the Electrical Performance and Bias Stability of Dual-Gate ITZO Thin-Film Transistors

Hydrogen impurities inevitably incorporated during fabrication deteriorate the performance and bias stability of indium-tin-zinc-oxide (ITZO) thin-film transistors (TFTs). This study addresses this challenge by employing SF₆ plasma treatment to passivate these defects in dual-gate (DG) ITZO TFTs. We systematically investigate the effect of treatment time on electrical properties and stability. The optimal 30 min treatment successfully suppresses hydrogen-induced degradation. While mobility slightly decreases from 38.56 to 32.87 cm²/V $\cdot $ s, key stability metrics are dramatically improved: the subthreshold swing (SS) is reduced to 0.153 V/dec, and threshold voltage shifts under positive bias temperature stress (PBTS), negative bias temperature stress (NBTS), and negative bias temperature illumination stress (NBTIS) are minimized to −0.35, −0.06, and −0.59 V, respectively. This work demonstrates that SF₆ plasma treatment is a highly effective strategy for enhancing the reliability of metal oxide TFTs for next-generation displays.