Electron beam column for in-line applications featuring enhanced imaging of high-aspect-ratio structures by selective detection of on-axis secondary electrons

摘要

Abstract: The scanning electron microscope presented here allowsfor enhanced and selective detection of on-axissecondary electrons by a novel two-detector arrangementin combination with a beam separator. It is based onour high-resolution electron beam column. The off-axissecondary electrons are recorded by a conventionalin-lens detector. The on-axis secondary electrons fromthe primary electrons and deflects them towards ascintillator-based detector. The detector for on-axissecondary electrons can either work in a stand-alonemode or in combination with the in-lens detector. Dueto the symmetry of its deflection field, the beamseparator causes no first-order chromatic aberrationsto the primary beam and the spatial resolution is notdeteriorated. A first experimental evaluation hasdemonstrated the enhanced capabilities of this system.!7