Fig. 5. Evolution of the transfer curve of a-IGZO TFTs with Al₂O₃ gate insulator for (a) and (c) T_dep = 150 °C (high hydrogen, HH) and (b) and (d) 300 °C (low hydrogen, LH) under NBTS (V_g = −20 V, T = 60 °C, 10 000 s) and PBTS (V_g = +20 V, T = 60 °C, 10 000 s), respectively. (T_post-ann = 350 °C).