Noble-Gas Ion Bombardment on Clean Silicon Surfaces Studied Using Ellipsometry and Desorption

摘要

The influence of low-energy noble-gas ion bombardement on clean silicon surfaces was studied. At a low dose and at a high dose quite different behaviors are observed, finally resulting in a steady state. The low-dose behavior reflects the amorphism (a loss of long-range order) of the original c-Si surface layer. In order to explain the high-dose behavior, desorption experiments were carried out; information concerning the anneal behavior of the damaged implanted surface layer is obtained. During an anneal-step up to 800 C of the damaged layer, the noble gas is driven out and a recovery from damage occurs, resulting in the initial cristalline state. Upon termination of ion bombardment changing ellipsometric values, called self-anneal behavior, are still observed.