On the cumulative distribution function of the defect centric model for BTI reliability

The validity of the existing cumulative distribution function (CDF) formulas for the defect centric model (DCM) is discussed, especially in the low defect number regime (defect number < 3). After finding their limitations, we propose an improved DCM CDF formula which well accounts for the low defect number regime, becoming important in advanced CMOS technologies with scaled devices. The benefits of the revisited DCM CDF formula are experimentally demonstrated on pMOS devices from 28 nm FDSOI technology subjected to BTI stress as well as on Monte Carlo simulated Vth data.