Reduced surface roughness of solid thin films prepared by alternating-bias, radio-frequency magnetron sputtering

Surface roughness that is associated with thin-film deposition has a direct effect on the optical, electrical, and mechanical quality of solid-thin-film devices. The effect of using alternating bias during rf-magnetron sputtering Of SiO2 on Si substrate was investigated, and it was proven experimentally that modulating the plasma flow by means of alternating bias produces more even deposition of the sputtered material. This effect was verified by analyzing the envelope of the reflection fringes that were recorded during the thin-film deposition process, and by observing the power reduction in the are-shaped scattering that is associated with mode excitation of a rough-surface waveguide. (C) 2003 Optical Society of America.