Charge effects in dielectric films of MIS structures being under high-field injection of electrons at ionizing radiation

Abstract

In this work we study influence of α-particles and gamma-ray onto MIS structures being under high-field FowlerNordheim injections of electrons into the gate dielectric. We discover that ionizing current occurring at the time of radiation of MIS structures being under high-field injection of electrons by constant current can significantly lower density of injection current and decrease electric field in the dielectric film. We demonstrate that from analysis of time dependency of voltage across MIS structure at the time of constant current flowing we can determine a value of ionization current. The effect can be utilized for sensors of radiations which allow to control both intensity of radiation and a value of integral absorbed dose of ionizing radiation. We develop a model describing processes of change of charge state of MIS structures being under high-field injection at radiation influence. This model takes into account an interaction of injected electrons with products occurring in the dielectric film as a result of ionization radiation.