New Insight Into Negative Bias Temperature Instability Degradation During Self-Heating in Nanoscale Bulk FinFETs

Abstract

In this letter, we investigate the threshold voltage shift ( $\Delta {V} _{\textsf {th}}$ ) by negative bias temperature instability (NBTI) coupled with the self-heating effect (SHE) in a 14-nm bulk ${p}$ -FinFET. To analyze the effect of NBTI in the presence of the SHE, the DC stress was performed under high-bias conditions, i.e., gate bias ${V}_{\textsf {GS}} = -{1.3}$ V and drain bias ${V}_{\textsf {DS}}$ up to −1.3 V at room temperature, which was usually referred to as hot-carrier degradation (HCD) stress. It has been observed that the long-time (10 s ~ 103 s) power-law time exponent ( ${n}$ ) decreases as ${V}_{\textsf {DS}}$ increases, and ${n}$ was very close to that of NBTI-induced $\Delta {V} _{\textsf {th}}$ rather than HCD-induced $\Delta {V} _{\textsf {th}}$ at ${V}_{\textsf {GS}} = {V}_{\textsf {DS}} = -{1.3}$ V. For the first time, computer-aided design simulations were performed in combination with SHE and NBTI. The effect of NBTI in ${p}$ -FinFET is confirmed to contribute significantly to $\Delta {V} _{\textsf {th}}$ under DC HCD stress because of SHE. The influence of SHE is mitigated in high-frequency circuit operation, but special attention should be paid to NBTI issues due to the potential occurrence of SHE as the technology nodes shrink.