A precise model of the transient response of MNOS memory capacitors

An accurate one-dimensional model of the metal-silicon nitride-silicon dioxide-silicon (MNOS) capacitor is presented. The numerical solution technique uses space and time discretization to implicitly solve the carrier current equations in the insulators and the partial differential equations that describe the static and dynamic carrier distributions in the silicon. Avalanche carrier generation and avalanche carrier injection mechanisms are included. The improved understanding of the physical behavior that ensues is used to design a fast programming transient (<1 microsecond) for the MNOS capacitor with a silicon dioxide thickness of 50 Å.