Low-loss image for surface scanning electron microscope

Images have been obtained from the surface scanning electron microscope (SEM) by collecting backscattered electrons that have suffered a small energy loss in the specimen. This method can be applied to smooth specimens when viewed at oblique incidence. The modulation depth in the electron channelling pattern can be as great as 75%, as compared with 2-5% for the secondary electron signal or 40% for the backscattered electron signal. In surface microscopy, the image is obtained from a surface layer of thickness about 100 Å, so that the effects of electron penetration are greatly reduced. A point-to-point resolution of 170 Å has been obtained. © 1971 The American Institute of Physics.