Consideration of recovery effects during NBTI measurements for accurate lifetime predictions of state-of-the-art pMOSFETs

Abstract

The NBTI recovery phenomenon leads to a fast reduction of the stress induced electrical device parameter degradation after end of stress. Delay times between device-stress and -characterization within NBTI-experiments affect the measurement values of degradation. This work discusses the impact of these delays on lifetime prediction for technology qualifications. For this reason we investigate delay times from 1µs up to 60s and stress times from 100ms up to 250 000s. A correlation between stress time, delay time induced recovery and error in predicted lifetime is elaborated for the first time. The influence of the recovery on single device stress experiments, on the voltage acceleration and finally on lifetime extrapolation is discussed. Furthermore we give simple guidelines for measurement requirements and essential stress times for accurate lifetime evaluations.

Energetic mapping of oxide traps in MoS 2 field-effect transistors

“…These issues are known as biastemper ature instabilities (BTI) and are a serious reliability concern in conventional Si technologies [20][21][22][23][24][25]. During the last decade BTI in Si FETs has been thoroughly characterized [22,24,[26][27][28]. In particular, charge trapping was identified to be a crucial contributor to the degradation [19,29].…”

A method for negative bias temperature instability (NBTI) measurements on power VDMOS transistors

“…The proposed method, therefore, seems to offer measurements short enough to capture the faster part of the slow degradation component, which should be sufficient for rather reliable prediction of device lifetime (even a 60 s long delay in measurements was shown not to cause significant overestimation of NBTI lifetime [31]). In addition, the proposed method provides the full range I-V characteristics that can be used to determine not only threshold voltage but also to extract and/or calculate some other important device parameters, such as channel carrier mobility and transconductance, which may provide better insight into the effects of NBTI.…”

Characterization of fast relaxation by oxide-trapped charges under BTI stress on 64 nm HfSiON/SiO2 MOSFETs

“…= 0 V by sweeping V g from 0 to −1.5 V; for this measurement, V g,str was periodically interrupted at intervals from 1 μs to 5 ms. V th was defined as V g that yielded 40) The time to reach the device reliability criterion under the BTI stress condition was obtained by extrapolating the curve of ΔV th versus BTI stress time t s measured at each V g,str . 32) All electrical measurements were performed using a Keysight B1500A semiconductor device analyzer equipped with a B1530A waveform generator/fast measurement unit.…”

“…30) In addition, when the device lifetime t L at operating voltage V op is measured by extrapolating the time taken in an acceleration test to reach the criterion that ensures the reliability of the device, the t L estimated from these BTI degradation curves obtained under slow measurement (SM) configurations is distorted. 32) Therefore, continuous investigation of BTI degradation characteristics in various measurement configurations is required, and a t L estimation model that considers the recovery effect of BTI degradation by measurement phase is required for accurate prediction of MOSFET t L…”