Time dependent variability in RMG-HKMG FinFETs: Impact of extraction scheme on stochastic NBTI

Effect of mobility variation (Δμ
_eff
) during NBTI stress is well documented for larger area devices. In this paper, the effect of Δμ
_eff
on the statistics of NBTI degradation for small area devices is explored. Statistically relevant number of high-κ last Replacement Metal Gate p-FinFETs are characterized for NBTI stress to cover a range of three standard deviations for threshold voltage degradation (ΔV
_T
). It is shown that Δμ
_eff
can results into erroneous mean (μ) and sigma (σ) V
_T
shifts governing stochastic NBTI. The amount of error induced is found to depend on sense voltage (|V
_MEAS
|). Further, correlation of ΔV
_T
to V
_T0
is analyzed with V
_T0
estimated employing two different methods.