AC NBTI studied in the 1 Hz -- 2 GHz range on dedicated on-chip CMOS circuits

Abstract

We describe on-chip circuits specially designed and fabricated for the purpose of measuring the effect of AC NBTI on an individual, well-defined device in the wide frequency range on a single wafer. The circuits are designed to allow measurements in multiple modes, specifically, DC and AC NBTI (both interrupted and on-the-fly), on a single pFET and on a CMOS inverter, as well as charge-pumping characterization of the stressed pFET. The results indicate that AC NBTI is independent of the frequency in the 1 Hz -- 2 GHz range. The voltage and stress time acceleration is observed to be identical for both AC and DC NBTI stress.