Investigation of HCI effects in FinFET based ring oscillator circuits and IP blocks

Abstract

Hot carrier injection (HCI) effect with circuits running at very high frequency through overdrive (OD) can manifest under very long stress time and lower temperature where negative bias temperature instability (NBTI) is suppressed. On FinFET technology with presence of self-heating effects (SHE), it is important to decouple the effects to obtain accurate HCI modeling along with right duty cycle for the process wafer level reliability (WLR) requirements and design for reliability (DFR). We'd devised a unique Ring Oscillator (RO) test structure to characterize HCI duty cycle and compare with HCI duty extracted from the RO and IP aging results.