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A Focused Chromium Ion Beam



Adam V. Steele, Brenton J. Knuffman, Jabez J. McClelland, Jon Orloff


With the goal of expanding the capabilities of focused ion beam microscopy and milling systems, we have demonstrated nanoscale focusing of chromium ions produced in a magneto-optical trap ion source (MOTIS). Neutral chromium atoms are captured into a magneto-optical trap and cooled to 100 µK with laser light at 425 nm. The atoms are subsequently photoionized and accelerated to energies between 0.5 keV and 3 keV. The accelerated ion beam is scanned with a dipolar deflector and focused onto a sample by an einzel lens. Secondary electron images are collected and analyzed, and from these a beam diameter is inferred. The result is a focused probe with a one-standard-deviation radius as small as 205(10) nm. While this probe size is in the useful range for nanoscale applications, it is almost three times larger than is predicted by ray-tracing simulations. Possible explanations for this discrepancy are discussed.
Journal of Vacuum Science and Technology B


focused ion beams, chromium, MOTIS, nanotechnology


Steele, A. , Knuffman, B. , McClelland, J. and Orloff, J. (2010), A Focused Chromium Ion Beam, Journal of Vacuum Science and Technology B, [online], (Accessed April 24, 2024)
Created October 21, 2010, Updated February 19, 2017