A structural study of amorphous In2O3–ZnO films by grazing incidence X-ray scattering (GIXS) with synchrotron radiation

Grazing incidence X-ray scattering (GIXS) using synchrotron radiation is a very useful method for structural analysis of amorphous films. We investigated the structure of amorphous In2O3–ZnO films of three different Zn content (6.1, 10.7, 37.0 wt.%) utilizing GIXS and EXAFS at BL47XU in SPring-8. Radial distribution functions (RDFs) were obtained from the measurement data. Structural models were constructed by molecular dynamics (MD) and reverse Monte-Carlo (RMC) simulations, and the RDFs calculated from the simulations were compared with that observed. It was found that, in the three films, the average oxygen coordination numbers around the In and Zn ions were almost 6 and 4, respectively. It was concluded that the atomic arrangements of amorphous In2O3–ZnO were characterized by the increase in the number of distribution of the corner-sharing In–O–Zn bonds as compared with crystalline In2O3.