A hot-cathode plasma sputtering technique was used to fabricate highly transparent and conducting aluminum-doped zinc oxide (AZO) films on glass substrates from disk shaped AZO (Al 2 O 3 : 5wt.% and 2wt.%) targets. Using a target voltage V T =−200V and plasma excitation pressure P Ar =1.5×10 −3 Torr, the lowest resistivity of 4.0×10 −4 Ωcm was obtained at 400nm with a carrier density of 8.7×10 20 cm −3 and a Hall mobility of 17cm 2 /Vs. The analyzed structural properties of these films revealed that this lower resistivity was due to a decrease in the lattice spacing d (002) of the (002) plane parallel to the substrate surface. This decrease in lattice spacing was presumably caused by oxygen vacancies acting as an effective source of carrier electrons.