First, it reveals the main decreasing of resistivity of AZO films occurs in a very narrow range of middle vacuum, and high vacuum is dispensable. Second, it is a breakthrough that Ar⁺ sputtering cleaning can further decrease the resistivity of AZO films, meanwhile fulfil the surface texture process, which is very useful for photovoltaic applications. Thirdly, it demonstrates that more Zn²⁺ ions are replaced by Al³⁺, lattice oxygen decreases while oxygen vacancy increases greatly in middle vacuum, and thus conductivity of AZO films are improved significantly; Finally, it provides a very promising design for post-treatment equipment, where vacuum annealing, further optimization, surface texture can be carried out in an exactly controllable and low cost way.