Transparent conductive Al and Ga doped ZnO films deposited using off-axis sputtering

Al and Ga doped ZnO (AZO and GZO) films were deposited using an off-axis dc magnetron sputtering method. At the off-axis positions, both the mobility and carrier density increased, resulting in enhanced conductivity of both the AZO and GZO films due to an increase in the crystallinity. The lowest resistivities of the AZO and GZO films deposited at room temperature were 1.1 × 10 ^{- 3} Ω cm and 6.5 × 10^{- 4} Ω cm, respectively. Increasing the substrate temperature up to 130 °C led to a decrease in the lowest resistivity to 6.1 × 10^{- 4} Ω cm for the AZO films. The transmittance of all films was above 80% in the visible region. These results suggest that off-axis magnetron sputtering might be a potentially effective deposition method with the reduced bombardments from high-energy particles.