A high-current scanning electron microscope with multi-beam optics

• We have designed a new Multi-beam Scanning Electron Microscope (MBSEM) which potentially offers high-current.
• In this system 196 beams can be focused into one single spot by using a Micro Lens Array (MLA) in Objective lens.
• The MLA compensates for the spherical and chromatic aberration of the objective lens.

Recently we have proposed a new Multi-beam Scanning Electron Microscope (MBSEM) which potentially offers a higher current than a single beam SEM. In this system the primary electron beam is first separated into 196 beams by an Aperture Lens Array and then focused into one single spot by using a second Micro Lens Array (MLA) in the objective lens. This system potentially offers high current (200 nA), medium resolution (50 nm), and low landing energy (500 eV) for inspection tool of semiconductor. Here we report that we have achieved a practical setup, evaluated its performance, found difficulties in operating such a system and we draw conclusions about our proposition.

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