The impacts of inverter-like transitions on AC TDDB in a fast switching logic circuit

TDDB of High-k/metal gate (HK/MG) based NMOS in 16nm FinFET technology has been evaluated. In this paper, we investigated the impacts of channel current during transient and V_gd assisted recovery during off-state half cycle on TDDB lifetime and voltage acceleration factor (VAF). A 64-DUT array with AC signals on both gate and drain was constructed to make each DUT have inverter-like transitions. Data was also compared between device array and ring oscillators (RO) to inspect the integral influence of oxide breakdown on logic circuit. Results show a) frequency dependence exists regardless DC [1-2] or AC signal applied to drain, b) with the presence of HCI, inverter-like stress still lengthen TDDB lifetime, and c) V, shift due to AC BTI effects should be considered together with AC TDDB in a fast switching logic circuit.