Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5369656 | Applied Surface Science | 2007 | 6 Pages |
Zn-Sn-O (ZTO) films with continuous compositional gradient of Sn 16-89 at.% were prepared by co-sputtering of two targets of ZnO and SnO2 in a combinatorial method. The resistivities of the ZTO films were severely dependent on oxygen content in sputtering gas and Zn/Sn ratio. Except for the films with Sn 16 at.%, all the as-prepared films were amorphous and maintaining the stable amorphous states up to the annealing temperature of 450 °C. Annealing at 650 °C resulted in crystallization for all the composition, in which ZnO, Zn2SnO4, ZnSnO3, and SnO2 peaks were appeared successively with increasing Sn content. Above Sn 54 at.%, the ZTO films were deduced to have a local structure mixed with ZnSnO3 and SnO2 phases which were more conductive and stable in thermal oxidation than ZnO and Zn2SnO4 phases. The lowest resistivity of 1.9 Ã 10â3 Ω cm was obtained for the films with Sn 89 at.% when annealed at 450 °C in a vacuum. The carrier concentrations of the amorphous ZTO films that contained Sn contents higher than 36 at.% and annealed at 450 °C in a vacuum were proportional to the Sn contents, while the Hall mobilities were insensitive to Sn contents and leveling in the range of 23-26 cm2/V s.