Intrinsic carrier mobility in amorphous In–Ga–Zn–O thin-film transistors determined by combined field-effect technique

Amorphous In–Ga–Zn–O (α-IGZO) is expected for thin-film transistors (TFTs) in next-generation flat-panel displays but its intrinsic properties are not understood well and different mobility models have been applied to different films. This letter reports that a universal mobility model is obtained using a field-effect technique and capacitance-voltage method. Electrical characteristics of α-IGZO TFTs subjected to different annealing are reproduced using the mobility model and different trap densities. The present achievement will be a necessary basis to establish device and circuit simulators for α-IGZO-based electronic applications.