Interface states and memory decay in MNOS capacitors

A method for measuring the density and energy distribution of interface states at the silicon-silicon dioxide interface in MNOS capacitors is described. Application of this method to capacitors fabricated on n-type substrates obtains a logarithmic dependence of the decay rate for stored holes on the interface state density generated during write-erase cycling. The slope of this relationship is strongly dependent on sample preparation. No dependence of the decay rate of electrons on interface state density was observed.