Tilt dependence of the secondary electron emission at low excitation energy

Influence of the specimen's slope on the secondary electron emission has been experimentally studied. Strong deviations from the inverse cos law have been observed and corresponding phenomenological equation (taking into account this deviation) is suggested. The consequences of the dependence on the topography contrast of low- and high-voltage scanning electron microscopy (SEM) image, especially for three-dimensional (3-D) reconstruction, are considered.