Next generation secondary electron detector with energy analysis capability for SEM

We report the working of a novel detector design based on a Bessel Box (BB) electron energy analyser in a scanning electron microscope (SEM). We demonstrate the application of our detector for elemental identification through Auger electron detection in an SEM environment and its potential as a complementary technique to energy dispersive X-ray (EDX) spectroscopy. We also demonstrate energy-filtered secondary electron imaging of a copper-on-silicon sample using an electron pass energy of 12 eV. LAY DESCRIPTION: Advancements in the field of the Scanning Electron Microscopy have been one of the major nanotechnology enablers. A Scanning Electron Microscope (SEM) generates a magnified image of the sample by bombarding it with an electron beam and detecting the electrons that scatter off the surface along with the electrons that are generated in the sample. Conventional detectors such as the Everhart-Thornley detector (ET) or through-the-lens (TTL) detectors, either offer little to no energy analysis (ET) or limited energy filtering capability (e.g the low-pass energy filter in TTL). This information is crucial to interpret the image of the sample under study. What is needed is a smart and compact detector that can detect electrons and furnish energy inside the SEM chamber. Here, we report a novel secondary electron (SE) detector design with energy analysis capability for use in scanning electron microscopes. The detector is based on the design of a Bessel Box (BB) energy analyser. We have designed and experimentally tested it in an SEM environment. The band-pass filter action of the detector enables the BB to be operated at a selected energy and allows a narrow window of energies to be detected for generating energy-filtered images.