Assessment of a 90nm PMOS NBTI in the form of products failure rate

NBTI is known to be the most critical MOS reliability issue for ppb-level product failures in giga-transistor integrated systems. A new assessment on 90 nm PMOS NBTI is presented. The new metric is based on product failure rate, which takes into account product integration. In a 90 nm technology, the product level failure rate (hazard rate) is estimated to be 3E-3 FIT @ worst case environmental conditions of 125°C and +10% Vdd. The 1 FIT lifetime is estimated to be 15 years. Degradation during burn-in test is less important since the failure rate saturates for long stress times. The assumed lognormal distribution of NBTI lifetime remains as a discussion issue.