LoTIS: A Lab to Market story

In the mid-2000s, McClelland and his colleagues in the NIST Center for Nanoscale Science and Technology determined that ionizing, or electrically charging, the cold atoms would further improve the ability to place an atom at a desired location on the surface of a nanoscale object. They also calculated that an ionized cloud of laser-cooled atoms should make a high-brightness focused ion beam.

Focused Ion Beams (FIB) are an established technology. FIBs are used to carve minute patterns into materials, and to initiate chemical reactions that construct nanoscale features. They are also a standard tool in the semiconductor industry for “circuit-edit,” the in-situ rewiring of chips to test circuit modifications. However, the increasing demands for smaller nanoscale devices required more accurate FIB technology than was currently available on the market.

In 2012, McClelland and NIST post-doctoral researchers Adam Steele and Brenton Knuffman built the proof-of-concept Low-Temperature Ion Source (LoTIS) on display here. In 2013, this device demonstrated that their laser-cooled ion beam had a 10-fold improvement in sensitivity and precision over existing FIB technology.

2D-MOT and Pusher Laser: A set of laser beams gather room-temperature cesium atoms from the vacuum chamber, cool them down 300 K to ~ 3mK, and push them to the next stage.

The Compressor and Optical Molasses: Laser beams make the atom beam denser and further reduce its temperature another 3mK to ~30 uK.

Electrostatic Extraction: The ionized atoms are accelerated into an ion beam by a pair of steel plates to which voltage is applied.