Impact of Duty Factor, Stress Stimuli, and Gate Drive Strength on Gate Delay Degradation with an Atomistic Trap-Based BTI Model

With deeply scaled CMOS technology, Bias Temperature Instability (BTI) has become one of the most critical degradation mechanisms impacting the device reliability. In this paper, we present the BTI evaluation of a single inverter gate covering both the PMOS and NMOS degradations in a workload dependent, atomistic trap-based, stochastic BTI model. The gate propagation delay depends on the gate intrinsic delay, the input signal characteristics, and the output load. Thus, the BTI degradation is investigated due to the impact of 1) duty factor, 2) periodic clock-based and non-periodic random input sequences, 3) gate drive strength. The inverter is chosen due to its representativity of other CMOS logic gates. The applied BTI model is stochastic, and the device parameters are orthogonally generated by distributions. Results show 3% and 27% degradation shifts on the distribution mean and worst-case. In addition, it is shown that the near-critical paths with lower drive strength cells are more susceptible to the BTI degradation than the critical paths with higher drive strength cells.