2 - Sources for ion beam treatment

Abstract

This chapter concentrates on ion beam sources used for industrial applications related to polymer materials. Ion beam implantation needs an ion beam source (ion beam accelerator). The ion beam source generates a flux of ions with high energy (speed) in a low-pressure atmosphere and includes an ion source (plasma discharge, spattered target), which produces a number of ions. There are two types of ion beam sources frequently used for polymer modification: ion beam implanters and plasma immersion ion implanters. The first method relies on the use of biased grids to accelerate a beam of ions out of a plasma source. There are two kinds of ion beam implanters: continuous and pulse ion beam. The second method of supplying energetic ions to a surface has many advantages for ion modification of polymers. It is more cost effective than beam line implantation, providing higher fluxes of ions per unit time, and eliminates the need to rotate the object being implanted to achieve modification of a three-dimensional surface. The ion beam implantation process of polymers differs in the case of ion beam source and plasma immersion ion implantation. In the case of ion beam source, the beam is generated separately from the polymer target. In the case of plasma immersion ion implantation, the ion flux is generated in space near the non-conducting polymer target. The two most important aspects of the ion implantation process for determining the modification achieved in the workpiece surface are the fluence, or total number of ions per unit area implanted, and the energy distribution of those ions.