Determination of slow- and fast-state distributions using high-temperature conductance spectroscopy on MOS structures

Abstract

This letter presents an experimental study of interface trap parameters versus energy. Our method is based on conductance measurements as a function of angular frequency and temperature G(ω, T ). The temperature is swept between 300 and 500 K in order to increase the mid-gap sensitivity. Capacitance as a function of voltage is used to establish the relation between the surface potential and the gate voltage at each temperature value. Then the conductance dispersion as a function of frequency is analysed in order to determine the distribution of the interface states D it and of their capture cross section σ n,p . Our results are in good agreement with those published on DLTS measurements. This confirms the capability of this technique compared with emission time spectroscopy, which implies a complex treatment of the measured data. Our G(ω, T ) procedure brings an accurate observation of two different populations of traps and we propose a classification of 'slow' and 'fast' states.