Invited Paper HI-WeA1
Delving into the Finer Details of Helium FIBID

Wednesday, October 24, 2018, 2:20 pm, Room 203B

Focused ion beam induced deposition (FIBID) of gaseous precursors enables localized template-free additive lithography at the nanoscale and is used in a range of applications, such as circuit edit in semiconductor engineering and the prototyping of nanodevices. To date, the majority of FIBID has used the gallium focused ion beam generated by the long-established liquid-metal ion source. However, with the development of the atomically sharp gas field-ionization source (GFIS) and subsequent emergence of the Helium Ion Microscope, FIBID using focused helium ion beams is increasingly of interest. The enhanced spatial resolution of helium FIBID over gallium FIBID and ability to deposit insulators free from gallium contamination are key areas of benefit.

The internal structure, composition, and overall shape of FIBID nanostructures and the influence of the deposition parameters thereon provide clues as to the growth mechanisms involved. Ultimately, the goal is to use this information to facilitate tunable FIBID in order to obtain nanostructures with a specific set of properties for a given application. I will present insights gleaned from scanning transmission electron microscopy (STEM) analysis of helium-FIBID nanostructures, where x-ray energy-dispersive spectrometry (XEDS) and new methods in “4DSTEM” diffraction are applied to obtain elemental compositions and grain orientation maps at the nanoscale with high sensitivity. The results are compared with those obtained for neon FIBID (the neon beam also generated by the GFIS source) and benchmarked against results from gallium FIBID. Several unique applications of helium FIBID drawing on the particular characteristics of helium-FIBID nanostructures will be discussed.