A novel ion source for high current ion implantation

Over the last decade the Bernas style of ion source has become generally accepted as industry standard for both high and medium current ion implantation. This has been due largely to its superior performance in source life and beam current production as well as its relative simplicity and maintainability. For Varian's latest high current ion implanters, the VIISion systems, a new source has been developed which builds upon the success of the Bernas architecture by adding an additional filament. Combined with new source control electronics the performance of this system with its highly symmetric plasma confinement and high input powers is exceptional. This paper describes the ion source and its control electronics. Its remarkable performance in the production of boron and multiply charged ions will also be discussed along with its suitability for very low dose implantation.