Optical emission spectroscopy of water vapor plasma in DC reactive magnetron sputtering of Zn

The optical emission spectra of water vapor plasma in a DC reactive magnetron sputtering system and the factors affecting the ZnO film deposition is investigated. The line spectrum intensities of atoms and molecules such as Zn, O, H and OH are measured and correlated to the dissociation and local plasma parameters of the magnetron sputtering discharge. In an Ar-H₂O plasma at increasing water vapor content, the ratio of the OI to ZnI and OI to H_α line was found to sharply increase as the H₂O concentration exceeded 40 to 50%. The addition of hydrogen peroxide to the water vapor reservoir for increasing reactive gas dissociation and atomic oxygen or OH concentration is proposed.