IONIZED CLUSTER BEAMS - PHYSICS AND TECHNOLOGY

Ionized cluster beam (ICB) deposition has been used to form thin films of metals, insulators, semiconductors and organic materials which hav e unique characteristics when compared to films formed using other tec hniques. In addition, the use of gas-phase atoms in the form of accele rated clusters has recently shown promise for surface modification app lications. A fundamental understanding of ICB deposition and related t echniques requires investigations of (1) the mechanisms which lead to the growth of large vapor phase clusters, (2) techniques for determini ng the size distribution of large vapor clusters, (3) the initial stag es of film nucleation, (4) film growth morphology related to lattice m ismatch and ion beam parameters. Clarification of the role of clusters in ICB deposition has been greatly aided by atomic scale imaging by t ransmission electron microscopy and scanning tunnel microscopy in the early stages of film growth. Emphasis is given to the formation of hig h-quality, epitaxial metallic films. Several applications of ICB films with respect to microelectronics, optical mirrors, compound materials and organic materials are discussed with emphasis on the special char acteristics of ICB films. Applications for gas-cluster processing are reviewed.