Annular Focused Electron/Ion Beams for Combining High Spatial Resolution with High Probe Current
Autor: | Anjam Khursheed, Wei Kean Ang |
---|---|
Rok vydání: | 2016 |
Předmět: |
010302 applied physics
Materials science Ion beam business.industry Astrophysics::Instrumentation and Methods for Astrophysics Analytical chemistry 02 engineering and technology Electron 021001 nanoscience & nanotechnology 01 natural sciences Ion Optics 0103 physical sciences Cathode ray Physics::Accelerator Physics Ray tracing (graphics) 0210 nano-technology Spectroscopy business Instrumentation Beam (structure) Electron-beam lithography |
Zdroj: | Microscopy and Microanalysis. 22:948-954 |
ISSN: | 1435-8115 1431-9276 |
Popis: | This paper presents a proposal for reducing the final probe size of focused electron/ion beam columns that are operated in a high primary beam current mode where relatively large final apertures are used, typically required in applications such as electron beam lithography, focused ion beams, and electron beam spectroscopy. An annular aperture together with a lens corrector unit is used to replace the conventional final hole-aperture, creating an annular ring-shaped primary beam. The corrector unit is designed to eliminate the first- and second-order geometric aberrations of the objective lens, and for the same probe current, the final geometric aberration limited spot size is predicted to be around a factor of 50 times smaller than that of the corresponding conventional hole-aperture beam. Direct ray tracing simulation is used to illustrate how a three-stage core lens corrector can be used to eliminate the first- and second-order geometric aberrations of an electric Einzel objective lens. |
Databáze: | OpenAIRE |
Externí odkaz: |