Impurity incorporation during rf sputtering of silicon oxide layers

Backscattering and channeling effect measurements have been used to analyse silica rf sputtered in argon atmosphere. Layers sputtered from fused quartz were found to be stoichiometric SiO2 irrespective of variations of sputtering parameters during film growth. Variation of power density (deposition rate) does not influence the Ar content. The amount of Ar increases with increasing bias voltage. The lowest Ar content (0.4 mol%) was found at zero bias voltage. Traces of backing material used to establish good heat transfer between substrate and anode plate have been incorporated during film growth. The amount of impurities increased with increasing bias voltage. Contrary to Ar incorporation it has been observed that the In content decreased with increasing deposition rate.