Ion Microscopy

Helium Ion Microscopy is a relatively young imaging and nanofabrication technique which is based on a gas field ionization source.
It rasters a narrow beam of helium ions as across the surface of the specimen to obtain high resolution surface sensitive images.
Usually secondary particles such as electrons are collected for image formation but also photons, backscattered atoms or sputtered sample atoms can be used for image formation.
Thanks to the very high brightness of the source a lateral resolution as small as 0.5\,nm can be achieved.
The method is in particular suitable for obtaining high resolution images of insulating samples (such as ceramic materials and biological samples) as the built in charge compensation allows to observe such specimen with out any additional conductive coatings.
In this contribution I will introduce the method and briefly introduce the underlying physics.
In the rest of the chapter a number of imaging modes will be discussed and selected examples will be presented.
Finally, an outlook is presented on the ongoing efforts to add analytical capabilities to the method.