LER and spacing variability on BEOL TDDB using E-field mapping: Impact of field acceleration

Understanding the impact of process variability on TDDB is crucial for assuring robust reliability for current and future technology nodes. This work introduces a lifetime prediction model that considers local field enhancement to assess the combined impact of die-to-die spacing variability and line edge roughness. The model is applied to 16 nm half-pitch BEOL interconnects assuming either the power law or the root-E as field acceleration model and the impact on lifetime reduction is discussed. In comparison with the ideal case of a straight line with a nominal spacing of 16 nm, a 1-sigma spacing variation of 0.6 nm and 1-sigma LER of 1 nm leads to ~ 3 orders of magnitude lifetime reduction when assuming power-law whereas this value is ~ 1 order of magnitude when assuming root-E.