Charge trapping characterization in the thin oxide layer/non‐conductive substrate system

Abstract

Abstract The Trapping properties of a thin oxide layer deposited on a non‐conductive substrate are investigated. This study is based on the charge trapping behaviour of defects, depending on their nature and their distribution. The injection of charges is made by means of the electron beam of a scanning electron microscope that exhibits a primary electron energy in the range 300–40 000 eV. Charge trapping characteristics are obtained by using the induced current method, which consists of measuring the evolution of the absorbed current induced by trapped charges in the metallic sample holder during the injection of charges. This method gives not only a quantitative determination of the amount of trapped charges but also the kinetics of charging. In order to characterize the role of the interface (thin oxide /substrate), several tests are performed with various primary energies allowing the oxide, the interface and the substrate to be explored successively, because an increasing primary electron energy corresponds to an increasing penetration depth. As an example, MgO/glass and MgO/enamel systems are investigated. Comparison between these different charging kinetics leads to a better understanding of the effect of the interface on the trapping properties of such systems. Copyright © 2002 John Wiley & Sons, Ltd.