Speaker
Description
Negative oxygen ion (O⁻) focused ion beams occupy a central role in secondary ion mass spectrometry (SIMS), enabling high-sensitivity analysis of electropositive elements through the ion yield enhancing mechanisms of oxygen bombardment. The implantation of oxygen both increases the ionization probability during the collision cascade and reduces the probability of secondary ion neutralization during the sputtering event, resulting in oxygen ion beams elevating positive secondary ion yields by several orders of magnitude relative to inert primary species.
SIMS with O⁻ beams serve a broad application space including semiconductor process metrology, geological geochronology, nuclear materials characterization, cosmochemistry, and biological studies — all sharing a common requirement for spatially resolved, sub-ppb sensitivity surface chemistry analysis of solid materials.
This presentation reviews the rationale for employing negative rather than positive ion beams, as well as the developments in O⁻ source technology for focused ion beams. Particular attention paid to the transition from legacy duoplasmatron sources to high brightness inductively coupled plasma (ICP) ion sources offering improved brightness, lower axial energy spread, beam current stability, and operational lifetime. Work on ion optical developments, and application results are presented, reflecting a sustained effort to advance spatial resolution, detection sensitivity, and quantitative accuracy of SIMS analysis.
| Email address | n.smith@oregon-physics.com |
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| Visitor's Visa | no |
| Classification | Other negative ion sources for fusion, accelerators, and other applications |