The granularity effect in amorphous InGaZnO${}_4$ films prepared by rf sputtering method

Abstract

We systematically investigated the temperature behaviors of the electrical conductivity and Hall coefficient of two series of amorphous indium gallium zinc oxides (a-IGZO) films prepared by rf sputtering method. The two series of films are $\sim$700\,nm and $\sim$25\,nm thick, respectively. For each film, the conductivity increases with decreasing temperature from 300\,K to $T_{\max }$, where $T_{\max }$ is the temperature at which the conductivity reaches its maximum. Below $T_{\max }$, the conductivity decreases with decreasing temperature. Both the conductivity and Hall coefficient vary linearly with $\ln T$ at low temperature regime. The $\ln T$ behaviors of conductivity and Hall coefficient cannot be explained by the traditional electron-electron interaction theory, but can be quantitatively described by the current electron-electron theory due to the presence of granularity. Combining with the scanning electron microscopy images of the films, we propose that the boundaries between the neighboring a-IGZO particles could make the film inhomogeneous and play an important role in the electron transport processes.

4 pages and 4 figures

References in corpus (4)

• Hall resistivity of granular metals
• Hall Transport in Granular Metals and Effects of Coulomb Interactions
• Crossover of electron-electron interaction effect in Sn-doped indium oxide films
• Quantum-interference transport through surface layers of indium-doped ZnO nanowires

Cited by in corpus (1)

• Electron effective mass and electronic structure in nonstoichiometric a-IGZO films