INVESTIGATION OF SILVER IN THE IONIZED CLUSTER BEAM DEPOSITION TECHNIQUE

lonized cluster beam deposition uses a beam of ionized, accelerated at om clusters to grow thin films. Late in 199l, following nearly 20 year s of development, synthesis of large clusters of zinc by homogeneous n ucleation was achieved through significant changes in two source param eters. Crucible pressure was increased from 2 Torr to over 1000 Torr a nd the nozzle was changed from cylindrical (1 mm x 1 mm) to converging -diverging (18 mm long and 0.4 mm in diameter at the throat). Such hig h vapour pressure is presently impractical for materials of industrial interest such as gold, silver, copper and aluminium. Recent results u sing gold with the converging-diverging nozzle at a pressure of less t han I Torr showed no significant synthesis of large dusters. The work presented here describes results using silver at an intermediate press ure of around 100 Torr. The deposition rate was intermediate (2.2 nm s (-1)) between that for gold (0.02 nm s(-1)) and that for zinc (4.3 nm s(-1)). Significant numbers of large clusters were not detected. The p urity of the silver influenced the appearance of the beam. X-ray and r oughness analyses of deposited films are presented.