High current mass spectrometer using space charge lens.

摘要

Charged particle beam apparatus includes a source 6, 8, 10, 12, 14 for forming a charged particle beam 18 along a beam axis, a mass analyzing magnet 22 for imposing on the beam 18 a magnetic field perpendicular to the beam axis, a resolving slit 24 downstream of the analyzing magnet 22 and a space charge lens 20 positioned between the source and the analyzing magnet in close proximity to the magnet entrance. The apparatus provides a mass spectrometer with high current capability while maintaining the size and weight of the system within acceptable limits. The apparatus is particularly useful in ion implantation systems.