Extremely Stable Dual Gate Coplanar Amorphous InGaZnO Thin Film Transistor With Split Active Layer by N2O Annealing

We report the effect of N
₂
O post-fabrication annealing (PFA) on the electrical stability of dual gate, active split amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT). Optimized N
₂
O PFA at 360 °C for 3 h results in threshold voltage (V
_TH
) close to zero and an increase in the on-current almost 2 times than as-fabricated TFT. N
₂
O annealed TFT exhibited robust V
_TH
stability under positive bias temperature stress at 60 °C and negative bias illumination stress, exhibiting ΔV
_TH
of 0.1 V ,and0.1 V, respectively, whereas as-fabricated TFT showed large ΔV
_TH
of ~ 10 V and -3 V. The X-ray photoelectron spectroscopy depth profile reveals the origin of such improvement as the increasing metal-oxide bonds and the reduction in oxygen vacancy/ OH related defects.