Influence of entropy properties on measured trap energy distributions at insulator-semiconductor interfaces

Abstract

By using a thermodynamical approach to the ensemble of interface traps of insulator-semiconductor interfaces, it is demonstrated that the entropy properties of the traps may have a considerable influence on measured energy distributions. Because experimentally obtained distributions are given on a free-energy scale, thermodynamics must be utilized when comparing with theoretical distributions of eigenenergy scales. Both the U-shaped energy distributions profiles, normally found for silicon–silicon dioxide structures, and the peaks, obtained in these distributions for samples being exposed to radiation or bias stress, would occur for reasonable entropy distributions even if the interface state distribution on an eigenenergy scale were constant.