CNST collaboration demonstrates nanoscale focused ion beam employing laser-cooled lithium atoms

December 15th, 2011 in Physics / General Physics

(PhysOrg.com) -- A team of researchers from the NIST Center for Nanoscale Science and Technology and FEI Company have adapted a commercial focused ion beam (FIB) column to use photoionized laser-cooled lithium atoms as an ion source, and demonstrated that NIST’s patented Magneto-Optical Trap Ion Source (MOTIS) offers imaging performance competitive with the liquid metal ion sources used in most FIBs.

In a MOTIS, a gas of atoms is laser-cooled to ≈ 100 μK and then photoionized. The ions are accelerated to the desired energy, forming a highly monochromatic beam that is amenable to nanoscale focusing when provided as input to a commercial focused beam column. The light mass and low surface sputtering rate of laser-cooled allowed the researchers to demonstrate non-destructive imaging with a characteristic focal spot size of 26.7 nm ± 1.0 nm at 2 kV.

As predicted theoretically, the focal spot size was shown to depend on the temperature of the laser-cooled atoms and on the energy. The researchers anticipate further improvements to the system spot size for enhanced imaging. These results demonstrate that NIST’s new ion source may enable a wide range of new applications — from nanoscale imaging and defect metrology to ion implantation and material modification.

More information: Nanoscale focused ion beam from laser-cooled lithium atoms, B. Knuffman, A. V. Steele, J. Orloff, and J. J. McClelland, New Journal of Physics 13, 103035 (2011). iopscience.iop.org/1367-2630/13/10/103035/

Provided by National Institute of Standards and Technology

"CNST collaboration demonstrates nanoscale focused ion beam employing laser-cooled lithium atoms." December 15th, 2011. http://phys.org/news/2011-12-cnst-collaboration-nanoscale-focused-ion.html