| AVS 65th International Symposium & Exhibition | |
| Advanced Ion Microscopy Focus Topic | Thursday Sessions |
| Session HI+AS-ThM |
| Session: | Advanced Ion Microscopy & Surface Analysis |
| Presenter: | Nico Klingner, Helmholtz Zentrum Dresden-Rossendorf, Germany |
| Authors: | N. Klingner, Helmholtz Zentrum Dresden-Rossendorf, Germany R. Heller, Helmholtz Zentrum Dresden-Rossendorf, Germany G. Hlawacek, Helmholtz Zentrum Dresden-Rossendorf, Germany J. von Borany, Helmholtz Zentrum Dresden-Rossendorf, Germany S. Facsko, Helmholtz Zentrum Dresden-Rossendorf, Germany |
| Correspondent: | Click to Email |
Existing Gas Field Ion Source (GFIS) based focused ion beam (FIB) tools suffer from the lack of a well integrated analytic method that can enrich the highly detailed morphological images with materials contrast. While Helium Ion Microscopy (HIM) technology is relatively young several efforts have been made to add such an analytic capability to the technique. So far, ionoluminescence, backscattering spectrometry (BS), and secondary ion mass spectrometry (SIMS) using a magnetic sector or time of flight (TOF) setups have been demonstrated.
After a brief introduction to HIM itself and a summary of the existing approaches I will focus on our own time of flight based analytic approaches. TOF-HIM is enabled by using a fast blanking electronics to chop the primary beam into pulses with a minimal length of only 20 ns. In combination with a multichannel-plate based stop detector this enables TOF backscatter spectrometry (TOF-BS) using He ions at an energy of only 30 keV. The achieved lateral resolution is 54 nm and represents a world record for spatially resolved backscattering spectrometry.
Finally a dedicated extraction optics for positive and negative secondary ions has been designed and tested. The setup can be operated in point and shoot mode to obtain high resolution SIMS data or in imaging mode to obtain lateral resolved maps of the sample surface composition. First experiments revealed a very high relative transmission of up to 76% which is crucial to collect enough signal from nanoparticles prior to their complete removal by ion sputtering. The mass resolution of 200 is sufficient for many life science applications that rely on the isotope identification of light elements (e.g.: C, N). The lateral resolution of 8 nm has been evaluated using the knife edge method and a 75%/25% criterion which represents a world record for spatially resolved secondary ion images.