Field acceleration factor extraction in MOL and BEOL TDDB

Recently a BEOL (Back End Of Line) and MOL (Middle Of Line) Time-dependent dielectric breakdown (TDDB) reliability test and fail rate projection methodology based on large data analysis was proposed and studied. However the extraction of one of the key model parameters, the field acceleration factor Y
_e
was ambiguously defined. If no enough caution is taken, a systematically lower γ
_E
will be obtained which leads to a pessimistic projection. In this work, the fundamental differences with two different extraction methods are systematically studied by both experiments and Monte Carlo simulations. A more realistic and robust method is then proposed, for a more accurate reliability projection.