HIGH-INTENSITY IONIZED CLUSTER BEAMS FOR SURFACE MODIFICATION - DEPOSITION AND EROSION

Surface modification may be achieved by deposition of slow clusters or by erosion due to the impact of very fast clusters. For both purposes , high-intensity cluster beams are desirable and can be generated for a number of materials by nozzle expansion of pure gas or vapor. Cluste r beams of zinc with mean cluster sizes of some thousand atoms per clu ster, and of silver with some hundred atoms per cluster, have been obt ained for the first time from pure vapor expansions. Mirrorlike thin f ilms have been deposited at high rates of about 100 nm/s of zinc, or 4 0 nm/s of silver, at 300 mm nozzle distance. Surface erosion resulting from cluster impacts at kinetic energies above 0.1 keV per cluster at om may be used for microstructuring via cluster beam lithography (CLI) . The diameters of the impact craters are estimated to determine the a chievable spatial resolution.