Ion-implanted reservoirs and self-organized growth

Interaction between clusters through e.g. coalescence and Ostwald ripening inhibits the study of individual cluster growth. However, using an ion-implanted reservoir we have been able to create a dilute morphology of non-interacting CoSi₂ clusters on a Si surface. In this scenario each cluster is connected to the implanted layer by a diffusive link, thus providing a continuous supply of cobalt. As cluster volume increases, the initially square shape is only stable up to a certain critical size, at which a shape transition occurs. A further increase of cluster volume results in a rapidly increasing length while the cluster width reduces back to α₀. The resulting wire-like structures of uniform width confirm all details of the transition as predicted by Tersoff and Tromp