Effects of electron-beam irradiation on In–Ga–Zn–O thin films

Crystallization of In–Ga–Zn–O (IGZO) thin films by electron-beam irradiation when observed with a transmission electron microscope (TEM) has been reported. Hence in this study, we have investigated deposition conditions and properties of films that could be easily crystallized in TEM observation. In a film deposited under high pressure, voids are observed, and such a film has high impurity concentration and is crystallized by electron-beam irradiation in TEM observation. In contrast, a dense film deposited under low pressure is not crystallized by electron-beam irradiation. Moreover, from a thin film transistor (TFT) fabricated using a film that can potentially be crystallized by electron-beam irradiation, normal characteristics cannot be obtained. However, by using a dense film, a TFT with less variation in characteristics can be fabricated.