The defect-centric perspective of device and circuit reliability — From individual defects to circuits

As-fabricated (time-zero) variability and mean device aging are nowadays routinely considered in circuit simulations and design. Time-dependent variability (reliability variability) is an emerging trend that needs to be considered in circuit design as well. This phenomenon in deeply scaled devices can be best understood within the so-called defect-centric picture in terms of an ensemble of individual defects and their time, voltage, and temperature dependent properties. The properties of gate oxide defects are discussed and it is shown how these properties can be used to construct time-dependent variability distributions and can be propagated up to transistor-level circuits.