Prediction of Thermally Accelerated Aging Process at 28nm

We introduce a methodology to predict degradation in an SoC device undergoing a thermally accelerated aging process. SoCs are usually stressed at high temperatures and voltages (above nominal) to accelerate their aging so that their reliability under nominal conditions can be predicted. Here we focus on the thermal acceleration process. We implement a ring oscillator-based test structure and consider its free-running frequency as our reference parameter to measure degradation. We analyze 500 hours of BTI-induced degradation behavior at different temperatures and observed that the final degradation can be confidently predicted from the measurements in first half of the experiment. This observation provides a new research avenue to predict reliability test results, such as HTOL, which lasts for 1000 hours and has a negative impact on the product’s time to market.