Interface state densities in different heterojunctions

Abstract

Interface states at the contact between the dielectric and semiconductor substrate substantially influence the characteristics of electron devices containing various metal-insulatorsemiconductor (MIS) structures. Several methods of determination of the distribution of interface states through the bandgap are used in characterization of microelectronic devices. Downscaling of dielectric stacks required for novel technologies, introduces several effects causing the standard methods to be not enough efficient. Here we pay particular attention to the Terman method, reconsidering its foundations in the case where quantum charge in silicon near the interface with dielectric has to be taken into account. In this work we attempt to describe C-V characteristics of MIS structures using analytical expression containing parameters that can be empirically extracted from the measured C-V characteristics, and thus extract interface states density distributions excluding the effect of quantum charge. Successful application of the method has been demonstrated on various MIS structures.