Contrast mechanism of negatively charged insulators in scanning electron microscope

The main features of negatively charged images are: bright regions are always accompanied by a dark region, which corresponds to the region above connecting lines in LSI, and dark regions seem to encroach the bright region. These features are explained by a new model, which contains redistribution and multiplication of secondary electrons, EBIC and space charge conduction of electrons in an insulator, surface potential distribution and voltage contrast.