Mechanism for reduced NBTI effect under pulsed bias stress conditions

A series of experiments are conducted to study the physical mechanism of reduced NBTI effects observed under pulsed bias conditions. A reduction of V/sub th/ and I/sub on/ is observed for pulse periods shorter than critical time constants that are believed to be associated with hole trapping and detrapping processes. A two time constant model is developed to explain the reduction of V/sub th/ and I/sub on/ as a function of pulse repetition frequency.