Hall-current ion source with improved ion beam energy distribution

Abstract

A Hall-current ion source with a narrow ion beam energy distribution is presented. A narrow ion beam energy distribution is provided by a utilization of a multi-chamber anode through which a working gas is applied and delivers a uniform working gas distribution in a discharge channel. Introduction of a working gas through a lower part of anode makes applied electric potential in a narrow area and leading to enhanced conditions for a working gas ionization, high ion beam current, high translation of a discharge voltage into a 'monochromatic' ion beam mean energy distribution. A multi-chamber anode with a slit exit for introduction of a working gas into area under anode is utilized to prevent a backflow of insulating and dielectric depositions on anode parts, and under anode area makes a nominal operation with reactive gases without a phenomenon called as 'anode poisoning' during long operating hours. The ion source with a shielded Hot Filament design shows very effective ion beam neutralization properties; it produces less heating of the substrate than a traditional one; it has a cleaner ion beam because its beam is not contaminated by the Hot Filament material particles. In the design with two Hot Filaments the ion source operation is extended for tens of hours.