| AVS 61st International Symposium & Exhibition | |
| Helium Ion Microscopy Focus Topic | Thursday Sessions |
| Session HI+2D+AS+BI+MC-ThM |
| Session: | Fundamental Aspects and Imaging with the Ion Microscope |
| Presenter: | Radovan Urban, University of Alberta and The National Institute for Nanotechnology, Canada |
| Authors: | R. Urban, University of Alberta and The National Institute for Nanotechnology, Canada R. Wolkow, University of Alberta and The National Institute for Nanotechnology, Canada J.L. Pitters, National Institute for Nanotechnology, Canada |
| Correspondent: | Click to Email |
Single atom tips (SATs) gained significant attention over the past decade because they serve as high brightness, field emission electron sources and gas field ion sources (GFISs). Small virtual source size makes these attractive candidates for advanced scanning imaging applications such as SEM, TEM, and scanning ion microscopy (SIM) as well as for non-staining ion beam writing applications.
The ion beam diameter σ, together with total ion current I generated by a single surface atom of W(111) nanotip, are crucial parameters which determine angular current density and brightness of gas field ion sources. It is, therefore, essential to understand underlying mechanisms that govern beam width. Furthermore, mapping both σ and I to a large parameter space of tip temperature, imaging gas pressure, and extraction voltage is necessary to optimize gas field ion source operation. In this contributions we will explore both σ and I as a function of temperature and extraction voltage at different imaging gas pressures using a field ion microscope (FIM) to monitor beam shape and total current. The qualitative model of our results will be also discussed. Finding “the best imaging voltage” for a SAT will be briefly discussed.