A new methodology for modeling Air-Gap TDDB

We present a methodology for predicting line-to-line reliability of Air-Gap schemes, which accounts for line-edge roughness and electric field enhancement. Our model is calibrated to the intrinsic reliability properties of the Air-Gap interface dielectrics, which are characterized by performing time-dependent dielectric breakdown measurements on planar capacitors. We validate our model to experimental TDDB data from Ru/Air-Gap semi-damascene interconnects and predict that deeper Air-Gaps, extending into the bottom interlayer dielectric, can significantly boost the reliability of Air-Gaps schemes.