Effect of driving frequency on the structure of silicon grown on Ag (111) films by very-high-frequency magnetron sputtering*

The effect of driving frequency on the structure of silicon grown on Ag (111) film is investigated, which was prepared by using the very-high-frequency (VHF) (40.68 MHz and 60 MHz) magnetron sputtering. The energy and flux density of the ions impinging on the substrate are also analyzed. It is found that for the 60-MHz VHF magnetron sputtering, the surface of silicon on Ag (111) film exhibits a small cone structure, similar to that of Ag (111) film substrate, indicating a better microstructure continuity. However, for the 40.68-MHz VHF magnetron sputtering, the surface of silicon on Ag (111) film shows a hybrid structure of hollowed-cones and hollowed-particles, which is completely different from that of Ag (111) film. The change of silicon structure is closely related to the differences in the ion energy and flux density controlled by the driving frequency of sputtering.