The computer simulation of energetic cluster-solid interactions

There is a growing interest in the application of accelerated clusters and molecular species as both implantation and analysis tools. Large clusters have been in use for the deposition of films and the soft landing of biomaterials for a number of years now. More recently, the use of fullerene as a sputtering ion in SIMS has lead to a revitalisation of academic interest in the technique-as witnessed by the recent SIMS XV conference-and a host of new potential applications in the identification of molecular species and molecular imaging. The use of even larger clusters employed with electro-spraying techniques has also been developed as a new analysis technique (DESI) created. The application of giant gas clusters combining a component of 'active' ingredient in a large inert cluster is making a large impact in the semiconductor world to provide a new method ('infusion doping') for shallow junction formation in silicon and for providing a tool for surface smoothing. It is clear that there are an increasing number of applications of energetic clusters in the materials world. In this paper, computer simulation techniques are employed to investigate why clusters are of such interest. In particular the role of cluster impacts on molecular desorption will be investigated and the effects of variable energy deposition for large gas clusters in infusion doping will be highlighted.