Combinatorial study of WInZnO films deposited by rf magnetron co-sputtering

The compositional dependence of co-sputtered tungsten indium zinc oxide (WInZnO) film properties was first investigated by means of a combinatorial technique. Indium zinc oxide (IZO) and WO3 targets were used with different target power. W composition ratio [W/(In+Zn+W)] was varied between 3 and 30 at% and film thickness was reduced as the sample position moved toward WO3 target. Furthermore, the optical bandgap energy increased gradually, which might be affected by the reduction in film thickness. All the WInZnO films showed an amorphous phase regardless of the W/(In+Zn+W) ratio. As the W/(In+Zn+W) ratio in WInZnO films increased, the carrier concentration was restricted, causing the increase in electrical resistivity. W cations worked as oxygen binders in determining the electronic properties, resulting in suppressing the formation of oxygen vacancies. Consequentially, W metal cations were effectively incorporated into the WInZnO films as a suppressor against the oxygen vacancies and the carrier generation by employing the combinatorial technique.

The film thickness and the sheet resistance (Rs) with respect to the sample position of WInZnO films, which is compositionally graded by rf power for each target, are exhibited.Figure optionsDownload as PowerPoint slideHighlights
► The compositional dependence of co-sputtered WInZnO film properties is first investigated.
► W cations work as oxygen binders in determining the electronic properties.
► All the WInZnO films show an amorphous phase regardless of the W/(In+Zn+W) ratio.
► W metal cations are effectively incorporated into the WInZnO films by the combinatorial technique.