Deposition of aluminum-doped zinc oxide films by RF magnetron sputtering and study of their structural, electrical and optical properties

Highly oriented undoped and aluminum-doped ZnO (AZO) films in the (002) direction were prepared by RF magnetron sputtering on glass substrates with specifically designed ZnO targets containing different amounts of Al(OH) powder as doping 3 source. A systematic study of the influence of deposition parameters such as Al(OH) content in the target, the target–substrate 3 distance (D ), deposition time and substrate temperature on the structural, electrical and optical properties of the as-grown AZO ts films was carried out. XRD shows that AZO (002) crystal grew parallel to the substrate. With increasing D the growth rate ts increased, while the substrate temperature did not affect the growth rate. The as-grown AZO films not only have an average transmittance of )85% in the visible region, but also have an optical bandgap between 3.2 and 3.64 eV, depending on the sputtering parameters. The resistivity of the film deposited at D s45 mm from a 4 wt.% Al(OH) -doped ZnO target was ts 3 approximately 9.8=10 V cm, showing semiconductor properties. y2 2003 Elsevier Science B.V. All rights reserved.