Wide area source of multiply ionized atomic or molecular species

摘要

Apparatus for generating multiply charged ions from a source of wide area for use in ion implantation is based upon electron beam plasma interactions which more efficiently create a large density of multiply ionized species than conventional plasma sources over a wide area (1-20 cm in diameter). The beam electrons are generated from a glow discharge electron gun operating in the abnormal glow discharge state. More multiply ionized species are created because of the larger number of electrons at high energy present in a beam created discharge as compared to conventional hollow cathode or thermionic cathode ion sources. By using a ring-shaped cold cathode beam electron generator it is possible to realize a wide area source 2-20 cm in diameter. This multiple ion source permits the realization of a fixed ion implantation energy using a lower electrostatic potential because multiply ionized species are accelerated rather than singly ionized species.