Oxygen-Dependent Instability and Annealing/Passivation Effects in Amorphous In–Ga–Zn–O Thin-Film Transistors
This letter discusses the reason for the instability of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film tran- sistors (TFTs) under both positive and negative bias stresses. This instability is significantly influenced by the oxygen content in the bulk IGZO and the surrounding environment. The as- fabricated low-temperature devices can only endure a single po- larized bias stress. An a-IGZO TFT that is stable toward both positive and negative bias stresses with large relaxation times of 95 × 10 4 and 371 × 10 4 s, respectively, is achieved by annealing and passivation. Index Terms—Bias stress, IGZO, stability.