Theory of non-steady-state interfacial thermal currents in MOS devices, and the direct determination of interfacial trap parameters

Abstract

Generalized equations are derived that permit the determination of the non-steady-state, thermal current vs temperature characteristics due to the emission of charge from interface states in MOS devices when the temperature increases uniformly with time. The equations are applicable to any trap distribution that extends over more than about 4kT in energy; the equations for discrete traps are also presented. The important result emerging from this work is that in the case of distributed traps the I−T characteristic is a direct reflection of the energy distribution of the interface traps. Furthermore, it is shown how the attempt-to-escape frequency ν of the traps and, hence, their capture cross-section may be determined. The determination of the trap density and energy and ν for discrete trap levels is also discussed.