Rapid determination of "slow" states and "fast" states densities using thermally stimulated conductance spectroscopy on metal-oxide semiconductor capacitors

Both effects of oxide and interface traps have an impact on C(V) and G(omeg a) curves, hence, we propose to estimate the contribution of "slow'' states and "fast" states with the conductance technique in order to evaluate thei r contribution as a function of temperature. Silicon metal-oxide semiconduc tor (MOS) structures show a frequency dispersion of the equivalent conducta nce due to carriers recombination at interface states. We have observed on conductance measurements a contribution of "fast states" which correspond t o the high-frequency peak, and a low-frequency plateau due to the influence of "slow states" on G(omega, V) curves. We propose to extract the traps di stribution at each temperature, in dissociating the "slow" states and "fast " states as a function of energy in band-gap. We estimate the capture cross -section with this conductance method which is proportional to frequency. T he use of the G(omega, T) technique permits a clear identification of two t raps populations. These populations give a better description of "slow" and "fast" states contribution in MOS devices. (C) 2001 Elsevier Science Ltd. All rights reserved.