CLUSTER BEAM DEPOSITION - OPTIMIZATION OF THE CLUSTER BEAM SOURCE

Cluster beams from supersonic nozzle expansions of a vapor-inert gas mixture are being used for thin film formation of metals or refractory compounds. The cluster beam source is optimized with respect to enlarging the deposition area, given by the width of the cluster beam, and lowering the effective pumping speed for the carrier gas argon. With silver as a representative material for our source, the cluster beam diameter measured at 0.78 m downstream of the nozzle was 94 mm, corresponding to a beam angle of 6.8 degrees, or 0.011 sr, and the deposition rate was up to 14 nm/s. The effective pumping speed of the nozzle discharge chamber could be lowered to 0.1 m(3)/s at 25.5 Pa. The cluster beam used for thin film formation contained up to 20% of the total silver flux out of the nozzle. (C) 1995 American Vacuum Society.