Design of an Ultra-High Resolution SEM for Enhanced Analysis
The column is equipped with a well-known single-pol e bjective lens [2] that creates a strong magnetic  field around the sample, thus dramatically decreasi ng optical aberrations. Design optimization and combining the magnetic immersion field with the ele ctrostatic field [3] further improves the resolutio n to less than 1.1 nm at 1 kV. For analytical purpose s (EDS or EBSD) or for use with a FIB column however, the immersion magnetic field becomes a com plication due either to curvature of signal electron trajectories or beam splitting of ion-isot opes.
Detection Systems of Ultra-High-Resolution SEMs
For most current Scanning Electron Microscopes (SEM), the traditional Everhart-Thornley secondary electron (SE) detector and annular backscattered electron (BSE) detector are complemented with several detectors placed in the column. To choose the right system suitable for appropriate application is a challenging task. TESCAN introduced two ultra-high-resolution SEM columns [1], [2] in the last two years. Here, we present a comparison of both systems and introduce recent improvements. Both systems allow angular filtering of SE, energy-filtering of BSE and angular BSE selection.
New lens for a low‐voltage scanning electron microscope
This article introduces the idea of a ‘‘half ’’ pole‐piece to modify single pole‐piece lenses, enabling them to form an electron probe a few millimeters in front of the pole face. This modified single pole‐piece lens has relatively low spherical and chromatic aberration coefficients. If 2 mm is an acceptable working distance, then a 6‐A radius probe can be made using 5‐kV electrons.