Scanning helium ion microscope

[2] Similar to other focused ion beam techniques, it allows to combine milling and cutting of samples with their observation at sub-nanometer resolution.

[3] In terms of imaging, SHIM has several advantages over the traditional scanning electron microscope (SEM).

Owing to the very high source brightness, and the short De Broglie wavelength of the helium ions, which is inversely proportional to their momentum, it is possible to obtain qualitative data not achievable with conventional microscopes which use photons or electrons as the emitting source.

Compared to a SEM, the secondary electron yield is quite high, allowing for imaging with currents as low as 1 femtoamp.

The detectors provide information-rich images which offer topographic, material, crystallographic, and electrical properties of the sample.

An Orion Nanofab helium ion microscope by Zeiss Microscopes
Comparison of SEM (top) and SHIM (bottom) images of mouse enamel. SHIM images have a superior depth of field , showing internal structure in enamel tunnels, which appear as black spots in SEM images. [ 1 ]