The extraction of negative carbon ions from a volume cusp ion source
Melanson, S., Dehnel, M., Potkins, D., McDonald, H., Hollinger, C., Theroux, J., . . . Tarvainen, O. (2017). The extraction of negative carbon ions from a volume cusp ion source. In D. Faircloth (Ed.), NIBS 2016 : Fifth International Symposium on Negative Ions, Beams and Sources (pp. 040001). AIP Conference Proceedings, 1869. AIP Publishing. doi:10.1063/1.4995777
Published inAIP Conference Proceedings;1869
Copyright © 2017, AIP Publishing LLC. Published in this repository with the kind permission of the publisher.
Acetylene and carbon dioxide gases are used in a filament-powered volume-cusp ion source to produce negative carbon ions for the purpose of carbon implantation for gettering applications. The beam was extracted to an energy of 25 keV and the composition was analyzed with a spectrometer system consisting of a 90° dipole magnet and a pair of slits. It is found that acetylene produces mostly C−2 ions (up to 92 µA), while carbon dioxide produces mostly O− with only trace amounts of C−. Maximum C−2 current was achieved with 400 W of arc power and, the beam current and composition were found to be highly dependent on the pressure in the source. The beam properties as a function of source settings are analyzed, and plasma properties are measured with a Langmuir probe. Finally, we describe testing of a new RF H− ion source, found to produce more than 6 mA of CW H− beam.