Toward the Development of High-Performance Direct Electron Detectors by Means of TCAD Simulations

A CMOS image sensor (CIS) is simulated thanks to a TCAD environment for the direct detection of electrons in a transmission electron microscope (TEM). Two main parameters are studied, the detector gain and the modulation transfer function (MTF), in the case of a conventional beam energy equal to 200 keV. Investigations are carried out on the substrate characteristics such as the epitaxial layer thickness, its doping concentration, and the eventual back-thinning process. The best candidate is then compared with simulations and measurements performed on state-of-the-art commercial camera in integration mode and shows very promising results.