Behavior of oxygen in zinc oxide films through thermal annealing and its effect on sheet resistance

► Improvement of the crystallinity of ZnO film by Post-deposition annealing. ► Decrease of resistivity of ZnO film by post-deposition annealing. ► Formation of oxygen vacancy in ZnO film with desorption of O2. ► Recover of the resistivity by annealing in O2. ► The oxygen vacancies are compensated by annealing in O2 with diffusing into the film.