Expedient method of obtaining interface state properties from MIS conductance measurements

Abstract

In obtaining accurate values of interface state density and majority carrier capture cross section for SiSiO 2 interfaces from MIS capacitor admittance measurements, it has been necessary to analyze considerable data. The reason for this is a new effect described previously, namely the large dispersion of interface state time constant caused by fluctuations of surface potential. A computer program briefly outlined here has been developed which calculates interface state properties from a minimum of measured input data. The data required are: (i) low frequency capacitance vs. bias to get surface potential, (ii) admittance vs. frequency at fixed bias to get standard deviation of surface potential, and (iii) admittance vs. bias at two frequencies to get interface state density and majority carrier capture cross section vs. energy. A listing of the computer program and a description of how to use it can be obtained on request.