An image of gold atoms on tin from a state-of-the-art scanning electron microscope (left) has relatively poor depth of field - only parts of the image are in sharp focus. By contrast, the entire image from a helium ion microscope image (right) is sharp and clear. NIST researchers are studying helium ion microscopes to improve measurements at the nanoscale that are important to the semiconductor and nanomanufacturing industries. A Scanning Helium Ion Microscope (SHIM, HeIM or HIM) is a new imaging technology based on a scanning helium ion beam. As the helium ion beam interacts with the sample, it does not suffer from a large excitation volume, and hence provides sharp images on a wide range of materials. Compared to a SEM, the secondary electron yield is quite high, allowing for imaging with currents as low as 1 femtoamp.