LOW-ENERGY BI CLUSTER BEAM DEPOSITION

Electrical and chemical properties of Bi films produced by low-energy cluster beam deposition (LECBD) are studied and compared with those of films made by molecular beam deposition (MBD). For LECBD Bi films, increase of roughness and decrease of film grain size explain increase of resistivity and chemical reactivity to oxygen. Two phenomena are proposed to play a role in LECBD film growth: low surface diffusion of Bi clusters (relative to Bi2) and a high barrier to cluster coalescence. The present experiments show that growth of LECBD crystallized Bi films and the film grain size can be controlled by the size distribution of incident clusters.