ELECTRONIC TRAP MICROSCOPY - A NEW MODE FOR SCANNING ELECTRON-MICROSCOPY (SEM)

Insulating layers on conducting substrate are investigated by means of secondary electron field emission SEFE in a digital SEM. The kinetics of charge storage and release with time and temperature are controlled and recorded by an external computer. The evaluation is performed pixel-wise with respect to electronic trap concentration n(to), trap capture cross section sigma(c) and thermal activation energy E(t). Mapping of these trap parameters indicates hidden inhomogenities, defects and pre-treatments of the dielectric layers as well as the pattern of thermal bleaching and release of electrons. The latter ones appear as inhomogeneous processes starting with ''blinking'' centers and increasing their concentration with time and temperature.