Negative Bias Temperature Instability (NBTI) Die-Level Reliability Monitor

Negative bias temperature instability (NBTI) is an effect that causes a gradual shift in transistor threshold voltage (VT). It manifests as an absolute drain current IDsat decrease, transconductance gm decrease, and absolute VT increase. NBTI is primarily observed in p-channel MOSFETs when the gate-to-source voltage is negative.

NBTI is caused by charged defect densities in the gate oxide interface region. The VT shift is dependent on voltage stress on the gate terminal, temperature, and the duty cycle of the stressing voltage. Typical stress levels required to induce NBTI are temperatures in the 100-250 ºC range and electric field conditions across the oxide region higher than 6 MV/cm.

The NBTI prognostic cell is a part of the Sentinel Silicon™ library of prognostic (“canary”) cells.


NBTI Cell Layout – click to enlarge

Product Brief

Related Products