Effects of Measurement Temperature on NBTI

Abstract—Negative bias temperature instability (NBTI) is a pressing reliability issue for the CMOS industry. NBTI has been measured at stress temperature in most of the recent works. For the first time, this letter will demonstrate that, for a given number of defects, the threshold-voltage shift measured at stress tempera-ture can be less than half of its value at room temperature. As a result, the data obtained at different measurement temperatures should not be used for extracting the thermal enhancement of defect creation. In the future, this newly identified dependence on measurement temperature should be taken into account when estimating the NBTI limited lifetime of pMOSFETs. Index Terms—Bias temperature instability (BTI), defects, degradation, gate dielectric, lifetime, negative BTI (NBTI), oxynitrides. I