Magnetically filtered low-loss scanning electron microscopy

The resolution of the scanning electron microscope can be improved by mounting the sample in the high-field region of a condenser-objective lens. Low-loss electrons (LLEs) are scattered from the sample with an energy loss of less than a few percent of the incident energy. In the past, LLEs have been collected with a retarding-field energy filter. A way has been found to collect LLEs using a detector located within the magnetic field of the condenser-objective lens which provides the required energy-filtering action. This greatly simplifies the apparatus and makes it possible to obtain LLE images with less tilt of the specimen and with a higher beam energy than before.