Acceptance Angle Control for Improved Transmission Imaging in an SEM.

This contribution presents a simple, cost-effective modular aperture system enabling comprehensive acceptance angle control for STEM-in-SEM imaging. The system is briefly described, and different ways to use it are explained. To demonstrate the utility of the approach, a few samples are examined using the new system with comparisons to images from traditional SEM detectors. We show that the system enables conventional STEM imaging modes ranging from brightfield to high-angle annular darkfield (that is, Z-contrast), thin annular detection schemes, and even some non-conventional imaging modes.