Wide area source of multiply ionized atomic or molecular species
US4737688A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1986 |
| Grant date | Apr 12, 1988 |
| Priority date | — |
| Expiry date | Jul 22, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.