Optimal sampling for accelerated testing in 14 nm FinFET ring oscillators

The accuracy of accelerated lifetime tests may vary due to the choice of test conditions, which presents a problem in interpreting results. Furthermore, testing is generally performed on test structures which are simplified compared to circuits and systems. To have an in-depth understanding on the actual usage conditions, we use 14 nm FinFET ring oscillator as the test vehicle for accelerated testing, focusing on detecting front-end time dependent dielectric breakdown. The factors impacting errors in lifetime estimation are investigated, such as sample size, testing times, and number of inverters in the ring oscillators.