Realistic Projections of Product Fails from NBTI and TDDB

Statistical models for deconvolving the effects of competing mechanisms on product failures are presented. Realistic projections of product fails are demonstrated on high performance microprocessors by quantifying the contribution of NBTI, TDDB and extrinsic fail mechanisms. In particular, it is shown that transistor shifts due to NBTI manifest as population tails in the product's minimum operating voltage (Vmin) distribution, while TDDB manifests as single-bit or logic failures that constitute a separate sub-population. NBTI failures are characterized by Lognormal statistics combined with a slower degradation rate (ΔVt ~t0.15∼t0.25), in contrast to TDDB failures that follow extreme-value statistics and exhibit a faster degradation rate (ΔVt ~ t0.5).