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

This letter presents an experimental study of interface trap parameters ver sus energy. Our method is based on conductance measurements as a function o f angular frequency and temperature G(omega, T). The temperature is swept b etween 300 and 500 K in order to increase the mid-gap sensitivity. Capacita nce 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 d etermine the distribution of the interface states D-it and of their capture cross section sigma (n,p). Our results are in good agreement with those pu blished on DLTS measurements. This confirms the capability of this techniqu e compared with emission time spectroscopy, which implies a complex treatme nt of the measured data. Our G(omega, T) procedure brings an accurate obser vation of two different populations of traps and we propose a classificatio n of 'slow' and 'fast' states.