On the Physical Mechanism of NBTI in Silicon Oxynitride p-MOSFETs: Can Differences in Insulator Processing Conditions Resolve the Interface Trap Generation versus Hole Trapping Controversy?

Critical analysis of short-term negative bias temperature instability measurements: Explaining the effect of time-zero delay for on-the-fly measurements

“…2, any possible contribution from hole trapping must have fully saturated 9 before t 0 and hence will have no effect in plotted ⌬V T . Therefore, when devices have comparatively few hole trapping, 8 our results imply that once the t 0 delay is corrected for, the OTFM results would be consistent with each other and predict the same degradation as the UFM method. And these t 0 -corrected experimental data can then be interpreted by the H -H 2 model ͓Fig.…”

“…3,7 This "H 2 R-D" model also provides a consistent interpretation of temperature and field dependencies of NBTI for long-term stress, as extensively studied for devices with SiO 2 , plasma SiON, and thin thermal SiON dielectrics. 2,5,6,8 Although the classical "H 2 R-D" model provides an excellent interpretation for long-term stress data, our analysis shows that ͑1͒ the predictions of this model is inconsistent with the short term, sub-10 s, NBTI degradation ͓see Fig. 1͑b͔͒ and ͑2͒ in contrast to long-term degradation, the shortterm time exponent of NBTI degradation depends on the measurement techniques.…”

“…The origin of such degradation has been debated for the last few years, and it is now generally accepted that, for devices with SiO 2 , plasma SiON, and thin thermal SiON gate dielectrics, NBTI degradation results mainly from depassivation of Si-H bonds at the Si/dielectric interface and resultant diffusion of hydrogen species into gate dielectric and poly-Si. [1][2][3][4][5][6][7][8] As such, several groups have used the reaction-diffusion ͑R-D͒ model to interpret NBTI degradation. [1][2][3][4][5][6][7] At long stress time ͑t stress Ͼ 10-100 s͒, ⌬V T shows a power law behavior when plotted with respect to time ͑⌬V T ϳ At n ͒ with a consistent time exponent ͑n͒ of ϳ1 / 6.…”

“…[1][2][3][4][5][6][7] At long stress time ͑t stress Ͼ 10-100 s͒, ⌬V T shows a power law behavior when plotted with respect to time ͑⌬V T ϳ At n ͒ with a consistent time exponent ͑n͒ of ϳ1 / 6. This time exponent is independent of the measurement techniques used to monitor ⌬V T ͓e.g., ultrafast measurement ͑UFM͒, 9 "delay-free" on-the-fly I dlin measurement ͑OTFM͒, 2,3,5,6,8 etc.͔. The R-D model attributes the robust ͑constant over several decades in time 4 ͒ long-term n ϳ 1 / 6 exponent to the diffusion of molecular hydrogen ͑H 2 ͒.…”

“…Indeed classical I D -V G measurement provides an incorrect estimate of n at mid-to long stress time, due to unintentional recovery inherent in the measurement technique. 2,14 The uninterrupted OTFM eliminates the "recovery" problem 2,5,8,[14][15][16] 15 A point that is not always obvious, hence ignored, is the use of t 0 in the above calculation. Exact ⌬V T measurement using OTFM mandates the use of t 0 = 0.…”