In search of the high brightness high current combination: Ideas from electron microscopy/lithography

by Prof. Anjam Khursheed (National University of Singapore)

Wednesday 8 Jun 2016, 14:15 → 15:30 Europe/Zurich

503/1-001 - Council Chamber (CERN)

This talk will summarize some recent research projects in electron microscopy/lithography being carried at the National University of Singapore that may form the basis for collaboration projects with CERN. All these projects are aimed at obtaining high brightness (low emittance) together with high current in electron/ion focused beam systems. The first of these projects is based upon creating an aberration correction unit which can correct for both the chromatic and geometric aberrations of the final objective lens. Unlike most other aberration correction systems used in electron microscopy, this aberration design is based upon using an annular aperture together with multi-stage core lenses (ones that have on-axis electrodes). For the same beam current, they are predicted to make the final probe size smaller by over a factor of 50 compared to the conventional hole-aperture uncorrected beam. Multi-beam electron/ion focused beam systems also currently under investigation at the National University of Singapore. Some multi-beam system designs use an array of miniaturized electron/ion sources while others create separate beamlets from a single conventional source. The drive for multi-beam systems comes mainly from the semiconductor industry, where researchers are seeking to replace the single beam column by an array of hundreds to several thousands of focused beam columns. The third subject for this talk will be the development of ring-cathode electron/ion sources.  Ring cathode field emission sources can have surface emission areas that are typically orders of magnitude higher the conventional point-cathode source.  This in turn is expected to translate into orders of magnitude higher beam current for the same probe size if core-lens aberration correction is used. Recently, successful preliminary emission was obtained from a graphene ring-cathode source at the National University of Singapore, and these results, as well as future prospects will be summarized.

 

 

 

ATS Seminars Organisers: H. Burkhardt (BE), M. Modena (TE), T. Stora (EN)

Coffee / tea will be served after the seminar in front of the Council room "salle des pas perdus"