Effects of oxygen flows and annealing temperature on properties of cosputtering In2O3-Ga2O3-Zn thin films

The average transmittance (T_avg%) and optical energy gap (E_g) increased rapidly with increasing O₂ flow. The resistivity significantly increased with increasing O₂ flow for annealing temperature at 200°C, however the resistivity did not change with the O2 flow for the annealing temperature at 400°C. Hall mobility reached the highest value of 11.18 cm²V^-1sec^- when the O₂ flow is at 5 sccm and the carrier concentration decreased with the O₂ flow. With increasing O₂ flows, surface morphology displayed dense structure; the crystallinity of the ZnO phase increases and the ZnO phase is transformed to the InGaZn₇O₁₀ phase. Afterward, the mobility rose with the added O₂ flow. X-ray Photoelectron spectra of the O1s peaks of co-sputtered IGZO films, with increasing O₂ gas flows, an increase of OI caused both of T_avg% and E_g increased, and a decrease of OII created the resistivity increased and carrier concentration decreased.