Measurement of negative ion fluxes during DC reactive magnetron sputtering of Ti in Ar/O2 atmosphere using a magnetic-filtering probe

The flux of negative oxygen ions in a dc reactive magnetron discharge has been measured using a specially developed magnetic-filtering probe. The gridded probe which operates as a retarding field analyzer has a magnetic filter attached to the front entrance to suppress plasma electrons entering the device. As a result, the fluxes of unmagnetized negative ions with energies of higher than similar to 10 eV can arrive to an ion collector and contribute to the detected probe current. During the oxide mode of Ti-Ar/O-2 magnetron sputtering discharge, the measured negative ion flux is considered to be contributed by the sputtered O- ions generated at the target surface and the plasma O- ions created in the discharge volume. However, in specific discharge conditions, the sputtered ions are likely to dominate in the measured flux signal. As a result, the yield of the sputtered O- ions and associated energy flux can be examined. The magnetic-filtering probe could potentially be employed as a real-time diagnostic tool to monitor the sputtered O- flux as well as the oxide state of the target surface during reactive magnetron sputtering processes.