Optical spectroscopic study of the growth dynamics of radio-frequency-sputtered YBa2Cu3O(7-x) thin films

Abstract

An optical spectroscopic study of the plasma produced during rf sputtering of an YBa2Cu3O7-x target was performed to analyze two basic properties of the deposition process: resputtering effects and oxidation mechanisms. Strong emissions of all the species above a value of the target voltage were found. These observations are associated to a strong secondary electron emission of the target which originates a negative self-bias of the substrate and a subsequent resputtering by argon cations. The addition of different amounts of oxygen to the discharge reveals that preoxidation in the gas phase may decrease the oxygen content in the films: the oxidation of the films is dominated by atomic oxygen.