A comprehensive framework for predictive modeling of negative bias temperature instability

Abstract

Abslracl-A quantitative model is developed for the first time, that comprehends all the unique characteristifs of NBTI degradation. Several models are critically examined to develop a reactioddiffusion based modeling framework for predicting interface state generation during NBTI stress. NBTI degradation is found to be dominated by difTusion of neutral atomic and molecular hydrogen related defects. Additionally, the presence of hydrogen gettering sites such as unsaturated grain houndaries significantly enhance NBTI degradation, whereas hydrogen sources reduce NBTI degradation. The model also suggests the possible mechanisms for saturation. The model is calibrated over a range of stress temperatures and voltages. The model captures recovery, experimental delay and frequency effects successfully.

Scalable consistency-based hardware trojan detection and diagnosis

“…IC lifetime is influenced by a variety of phenomena that have been studied by the material science and semiconductor community, such as time dependent dielectric breakdown (TDDB) [15], thermal cycling (TC) [16], and negative bias temperature instability (NBTI) [17]. These phenomena are causing significant alterations of both delay and leakage char acteristics of a gate.…”

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

“…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 ͒. 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.…”

“…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][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. 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.͔.…”

“…This requires explicit consideration of H within the R-D framework, as this should be the first by-product after interface trap generation, before getting transformed to H 2 . 3,7 Although neutral charge state may not be a stable form of atomic hydrogen, its transient formation is indeed possible. 10 Therefore, in the generalized R-D model, diffusion of both H and H 2 and H ↔ H 2 conversion are explicitly incorporated in the R-D framework by the following equations: 11 Our simulation results, based on the solution of Eqs.…”