Imaging with the Helium Ion Microscope

Abstract

A newly developed technology, the helium ion microscope (HIM), provides high-resolution imaging with several benefits compared to the standard scanning electron microscope (SEM). First, the images provide high resolution because the helium beam can be brought to a focused probe size that can be as small as 0.25 nm. Second, the images provide contrast mechanisms that are often markedly different from the SEM. These contrast mechanisms can reveal topographic, composition, and other types of information about the sample. Third, compared to the SEM, the HIM images tend to be more surface-specific – revealing information about the surface without the confusing subsurface information. Fourth, the HIM can obtain high-resolution images even of insulating samples that would otherwise charge excessively in the SEM. The HIM is still in its infancy compared to the SEM, having only been commercially available for 7 years; however, it has already provided several unique advantages for the imaging of biological materials.