Study of Ar cluster ion bombardment of a sapphire surface

Abstract

Sapphire is one of the most useful materials for applications requiring high mechanical strength with chemical and thermal durability. In order to modify the mechanical characteristics of the surface of sapphire, we have considered the use of cluster ion implantation techniques. Cluster ions can provide a low-energy and high-current beam, because each constituent atom in the cluster, with sizes of a few thousands, has an energy of only a few eV. Impact processes of energetic cluster ions on solid surfaces are quite different from those of monomer ions because of multiple-collisions and high-density energy deposition within a local surface region. In order to make clear the bombarding effects, a study of surface modification of sapphire by Ar cluster ion beams has been performed. Cluster ion traces on solid surfaces were observed by STM and AFM to investigate the bombarding effects. It was found that the thickness of the damaged layer produced on sapphire depends strongly on cluster ion energy.