Helium ion microscopy

Abstract

The realization of a practical helium gas field ionization source (GFIS) enabled helium ion microscopy (HIM) as a new technique to image and modify materials and microstructures. After a brief overview of most common ultramicroscopy techniques (TEM, SEM, Gallium FIB) and HIM, we introduce the interaction fundamentals of helium ions with matter. A key element of that interaction is that the resulting signals for imaging, nanofabrication and analysis, i.e. the secondary electrons and backscattered ions, are to a very high degree localized around the incidence point of the helium beam. This simple fact allows the helium ion microscope to enable a new and unique view of surfaces and provide a new method for material modification.We highlight several applications for imaging and nanofabrication using the sub-nanometer sized helium probe of the HIM. © Springer-Verlag Berlin Heidelberg 2013.