In Situ Hall Effect Monitoring of Vacuum Annealing of In₂O₃:H Thin Films

Hydrogen doped In₂O₃ thin films were prepared by room temperature sputter deposition with the addition of H₂O to the sputter gas. By subsequent vacuum annealing, the films obtain high mobility up to 90 cm²/Vs. The films were analyzed in situ by X-ray photoelectron spectroscopy (XPS) and ex situ by X-ray diffraction (XRD), optical transmission and Hall effect measurements. Furthermore, we present results from in situ Hall effect measurements during vacuum annealing of In₂O₃:H films, revealing distinct dependence of carrier concentration and mobility with time at different annealing temperatures. We suggest hydrogen passivation of grain boundaries as the main reason for the high mobility obtained with In₂O₃:H films.