Abstract
Thin films of aluminum zinc oxide (AZO) were fabricated by DC reactive magnetron sputtering from 50 wt% Al/Zn metallic target. The structure and optical constants of AZO films were controlled by changing the oxygen (O
2
) flow rate. X-Ray diffraction revealed that the addition of oxygen transforms the crystalline nature of the metallic Al/Zn to completely amorphous film at 4.5 sccm. The film density, surface roughness and deposition rate were evaluated from X-ray reflectometry measurements and they were found to decrease strongly upon transformation from metallic to oxidic sputtering mode. The optical constants were extracted from the ellipsometry measurements. As O
2
flow increased from 4.5 to 30 sccm, the optical band gap increased from 4.74 to 5.33 eV whereas the refractive index decreased simultaneously. Low resistivity films were obtained as O
2
flow increased from 0 to 4 sccm whereas insulating films were obtained for O
2
flows above 4 sccm. The results indicated that by regulating the oxygen flow diverse ZAO films with diverse chemical stoichiometries and properties can be tuned.