Low-Resistive and Transparent AZO Films Prepared by PLD in Magnetic Field

Al₂O₃ - doped ZnO (AZO) thin films have been deposited onto glass substrates using the split target consisting of AZO (1 wt%) and AZO (2 wt%) by pulsed laser deposition method with an ArF excimer laser (λ=193 nm, 15 mJ, 10 Hz, 0.75 J/cm²). By applying magnetic field perpendicular to the plume, the lowest resistivity of 8.54×10^-5 Ω·cm and an average transmittance more than 91 % over visible range were obtained at a target to substrate distance of 25 mm for approximately 279 nm-thick-AZO film (1.8 wt%) grown at a substrate temperature of 230°C in vacuum. From the cross-sectional TEM observation and the XRD spectrum, a reason why low resistivity of the level of 10^-5 Ω·cm was reproducibly obtained was considered to be due to the fact that a disorder of crystal growth originated in the vicinity of the interface between the substrate and the film was suppressed in the application of magnetic field and the c-axis-orientation became of preference, which in turn, giving rise to the increase of mobility.