Comparative study of the sputtering process in the conventional and microwave-coupled hollow-cathode discharge

Abstract

The ablation rate of sample atoms in conventional d.c. hollow-cathode discharge was compared with that observed when a microwave field is superimposed on the discharge. On the basis of mass variation as well as of data from an electron microscope, it could be ascertained that the effect on a material of microwave irradiation decreases with increasing melting-point. The materials used in this study were zinc, copper, molybdenum and graphite. Thus, the enhanced emission intensity observed in the microwave-coupled hollow-cathode source is, at least for low-melting specimens, due to the combined effect of more efficient excitation and higher density of the atomic cloud within the cathode cavity.