Channeling Focussed Helium Ion Beams

Synopsis

The Helium Ion Microscope (Zeiss Nanofab) provides a focussed He+ ion beam (20 - 35 keV) that is finding applications in nanoscale milling and patterning, and surface-sensitive secondary electron imaging. The field-emission ion source enables a focused probe size of less than 1 nm, with beam currents of 0.01 – 100 pA. The localized source also means that the beam is spatially coherent and can therefore, potentially, provide image contrast from channeling and diffraction, similar to transmission electron microscopy. This talk will introduce this type of microscope and show results from scanning and transmission through crystalline Si nanomembranes.