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Ben Kaczer - One of the best experts on this subject based on the ideXlab platform.
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Critical Modeling Issues in Negative Bias Temperature Instability
ECS Transactions, 2019Co-Authors: Tibor Grasser, W. Goes, Ben KaczerAbstract:Both the physical mechanisms as well as the modeling of negative bias Temperature Instability (NBTI) have attracted growing attention during the last years. While the reaction-diffusion theory had been the dominant explanation for a relatively long period, a growing number of authors have recently voiced their doubts regarding its validity. We give a brief review of suggested models and highlight their strengths and, more importantly, their weaknesses. We take care not to get lost in the intricacies of the various models by only qualitatively discussing their features. As will be shown, this is more than sufficient to demonstrate considerable shortcomings. Finally, we summarize our latest modeling attempts which try to overcome the observed modeling contradictions and show comparisons to experimental data.
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positive and negative bias Temperature Instability on sub nanometer eot high k mosfets
International Reliability Physics Symposium, 2010Co-Authors: Marc Aoulaiche, Ben Kaczer, Robin Degraeve, Philippe Roussel, J Franco, T Kauerauf, Lars Ake Ragnarsson, Joshua Tseng, Thomas Hoffmann, G GroesenekenAbstract:For the first time, positive and negative bias Temperature Instability (P/NBTI) mechanisms in sub-nanometer EOT devices are investigated in this study. It is shown that PBTI degradation in sub-nanometer EOT devices occurs by interface degradation, additionally to the oxide bulk trap filling which is the dominant mechanism in over 1nm EOT devices. For NBTI, interface degradation remains as the main mechanism in sub-nano EOT devices, and additional high contribution of the high-k bulk defects can increase the degradation below 6A EOT.
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On the thermal activation of negative bias Temperature Instability
2009 IEEE International Integrated Reliability Workshop Final Report, 2009Co-Authors: Richard G. Southwick, Ben Kaczer, William B. Knowlton, Tibor GrasserAbstract:The Temperature dependence of negative bias Temperature Instability (NBTI) is investigated on 2.0nm SiO 2 devices from Temperatures ranging from 300K down to 6K with a measurement window of ∼12ms to 100s. Results indicate that classic NBTI degradation is observed down to ∼200K and rarely observed at Temperatures below 140K in the experimental window. Since experimental results show the charge trapping component contributing to NBTI is thermally activated, the results cannot be explained with the conventionally employed elastic tunneling theory. A new mechanism is observed at Temperatures below 200K where device performance during stress conditions improves rather than degrades with time, which is opposite to the “classical” NBTI phenomenon.
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A two-stage model for negative bias Temperature Instability
2009 IEEE International Reliability Physics Symposium, 2009Co-Authors: Tibor Grasser, Ben Kaczer, W. Goes, Th. Aichinger, Ph. Hehenberger, Michael NelhiebelAbstract:Based on the established properties of the most commonly observed defect in amorphous oxides, the E′ center, we suggest a coupled two-stage model to explain the negative bias Temperature Instability. We show that a full model that includes the creation of E′ centers from their neutral oxygen vacancy precursors and their ability to be repeatedly charged and discharged prior to total annealing is required to describe the first stage of degradation. In the second stage a positively charged E′ center can trigger the depassivation of P b centers at the Si/SiO 2 interface or K N centers in oxynitrides to create an unpassivated silicon dangling bond. We evaluate the new model to experimental data obtained from three vastly different technologies (thick SiO 2 , SiON, and HK) and obtain very promising results.
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Negative bias Temperature Instability on Si-passivated Ge-interface
2008 IEEE International Reliability Physics Symposium, 2008Co-Authors: Marc Aoulaiche, Ben Kaczer, B. De Jaeger, Michel Houssa, Koen Martens, Robin Degraeve, Philippe Roussel, Jerome Mitard, S. De Gendt, Herman MaesAbstract:Germanium pMOSFETs with silicon-passivated interface (Ge/Si/SiO2/HfO2) are investigated for negative bias Temperature Instability (NBTI). Even though a high initial interface state density is measured, the stack shows a robustness toward NBTI stress, and the 10 year lifetime is ensured with a gate voltage overdrive VG-Vth = -1.2 V.
Tibor Grasser - One of the best experts on this subject based on the ideXlab platform.
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Critical Modeling Issues in Negative Bias Temperature Instability
ECS Transactions, 2019Co-Authors: Tibor Grasser, W. Goes, Ben KaczerAbstract:Both the physical mechanisms as well as the modeling of negative bias Temperature Instability (NBTI) have attracted growing attention during the last years. While the reaction-diffusion theory had been the dominant explanation for a relatively long period, a growing number of authors have recently voiced their doubts regarding its validity. We give a brief review of suggested models and highlight their strengths and, more importantly, their weaknesses. We take care not to get lost in the intricacies of the various models by only qualitatively discussing their features. As will be shown, this is more than sufficient to demonstrate considerable shortcomings. Finally, we summarize our latest modeling attempts which try to overcome the observed modeling contradictions and show comparisons to experimental data.
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Controversial issues in negative bias Temperature Instability
Microelectronics Reliability, 2018Co-Authors: James H. Stathis, Souvik Mahapatra, Tibor GrasserAbstract:Abstract In spite of 50 years of history, there is still no consensus on the basic physics of Negative Bias Temperature Instability. Two competing models, Reaction-Diffusion and Defect-Centric, currently vie for dominance. The differences appear fundamental: one model holds that NBTI is a diffusion-limited process and the other holds that it is reaction-limited. Basic issues of disagreement are summarized and the main controversial aspects of each model are reviewed and contrasted.
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The impact of mixed negative bias Temperature Instability and hot carrier stress on single oxide defects
2017 IEEE International Reliability Physics Symposium (IRPS), 2017Co-Authors: Bianka Ullmann, M. Jech, Stanislav Tyaginov, Michael Waltl, Yu. Yu. Illarionov, A. Grill, Katja Puschkarsky, Hans Reisinger, Tibor GrasserAbstract:Even though transistors are rarely subjected to idealized bias Temperature Instability or hot carrier stress conditions in circuits, there is only a limited number of studies available on mixed bias Temperature Instability and hot carrier stress. Here we summarize the results of the first study of mixed negative bias Temperature Instability and hot carrier stress (drain stress voltage |Vstr D |> 0 V and gate stress voltage |Vstr D | ≥ |V DD |) at the single oxide defect level in nano-scale SiON pMOSFETs. We found that less defects contribute to a threshold voltage shift ΔV th during recovery and thus to the recoverable degradation than would be expected from a simple electrostatic model. Time-dependent defect spectroscopy measurements show that even defects at the source side of the oxide can remain neutral after mixed negative bias Temperature Instability and hot carrier stress although they are fully charged after homogeneous negative bias Temperature Instability stress. As a consequence, they do not contribute to a ΔV th drift after mixed negative bias Temperature Instability and hot carrier stress. We show that this unexpected reduction in the defect's occupancy can be consistently explained by non-equilibrium processes induced by the large drain voltage such as impact ionization.
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On the thermal activation of negative bias Temperature Instability
2009 IEEE International Integrated Reliability Workshop Final Report, 2009Co-Authors: Richard G. Southwick, Ben Kaczer, William B. Knowlton, Tibor GrasserAbstract:The Temperature dependence of negative bias Temperature Instability (NBTI) is investigated on 2.0nm SiO 2 devices from Temperatures ranging from 300K down to 6K with a measurement window of ∼12ms to 100s. Results indicate that classic NBTI degradation is observed down to ∼200K and rarely observed at Temperatures below 140K in the experimental window. Since experimental results show the charge trapping component contributing to NBTI is thermally activated, the results cannot be explained with the conventionally employed elastic tunneling theory. A new mechanism is observed at Temperatures below 200K where device performance during stress conditions improves rather than degrades with time, which is opposite to the “classical” NBTI phenomenon.
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A two-stage model for negative bias Temperature Instability
2009 IEEE International Reliability Physics Symposium, 2009Co-Authors: Tibor Grasser, Ben Kaczer, W. Goes, Th. Aichinger, Ph. Hehenberger, Michael NelhiebelAbstract:Based on the established properties of the most commonly observed defect in amorphous oxides, the E′ center, we suggest a coupled two-stage model to explain the negative bias Temperature Instability. We show that a full model that includes the creation of E′ centers from their neutral oxygen vacancy precursors and their ability to be repeatedly charged and discharged prior to total annealing is required to describe the first stage of degradation. In the second stage a positively charged E′ center can trigger the depassivation of P b centers at the Si/SiO 2 interface or K N centers in oxynitrides to create an unpassivated silicon dangling bond. We evaluate the new model to experimental data obtained from three vastly different technologies (thick SiO 2 , SiON, and HK) and obtain very promising results.
C. K. Maiti - One of the best experts on this subject based on the ideXlab platform.
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Negative bias Temperature Instability in strained-Si p-MOSFETs
International Journal of Nano and Biomaterials, 2018Co-Authors: S. Das, Tara Prasanna Dash, C. K. MaitiAbstract:Strained-Si p-channel metal oxide semiconductor field effect transistors (MOSFETs) have become the performance boosters beyond 90 nm technology node. Reliability study of these devices is essential as only a few reports are available on this. In this work, we have explored the degradation mechanisms in these devices due to negative bias Temperature Instability (NBTI). Device simulation results have been calibrated with reported experimental data and a good agreement is observed. The reliability study of these devices has been performed using the two-stage model for defect creation. Study of the drain current degradation and comparison of threshold voltage shift after stressing between the strained-Si and Si channel p-MOSFETs have been performed. The threshold voltage degradation in strained-Si channel p-MOSFETs is found to be considerably higher than that in the bulk-Si devices due to higher fixed oxide charge and interface trap densities at the strained-Si/SiO2 interface.
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Negative bias Temperature Instability in strain-engineered p-MOSFETs: a simulation study
Journal of Computational Electronics, 2010Co-Authors: Tapas K. Maiti, S.s. Mahato, C. K. Maiti, Pinaki Chakraborty, Subir Kumar SarkarAbstract:Negative Bias Temperature Instability (NBTI) in p-MOSFETs is a serious reliability concern for digital and analog CMOS circuit applications. Strain in the channel region affects negative bias Temperature instabilities, low frequency noise, radiation hardness, gate oxide quality and hot carrier performance. The understanding of these phenomena in strain-engineered p-MOSFETs from fundamental physics is essential. In this paper, technology CAD (TCAD) has been used to study the effects of strain on the negative bias Temperature instabilities in p-MOSFETs. A quasi two dimensional (quasi-2D) physics-based Coulomb scattering mobility model for strained-Si has been developed and implemented in Synopsys Sentaurus Device tool for device simulation to understand NBTI in strain-engineered p-MOSFETs.
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Impact of Negative Bias Temperature Instability on Strain-Engineered p-MOSFETs
2007Co-Authors: Tapas K. Maiti, S.s. Mahato, Subir Kumar Sarkar, C. K. MaitiAbstract:Negative Bias Temperature Instability (NBTI) of p-MOSFET parameters (threshold voltage, linear and saturation drain current, gate-drain capacitance, etc.) is becoming a serious reliability concern for digital and analog CMOS circuits. To maintain the current scaling trends, the understanding of the fundamental physics of failure mechanisms in p-MOSFETs is required.In this paper, technology CAD (TCAD) has been used to understand the mechanism of Negative Bias Temperature Instability (NBTI) in strain-engineered p-MOSFETs. Conditions for interface and bulk trap generation and their dependence on stress voltage and oxide eld, Temperature and time are discussed. The recovery of generated damage and its bias, Temperature and AC frequency dependence are also discussed. In this work, we use Sentaurus Tools for the simulation of the trap formation kinetics of the SinSiO2 interface and change in the threshold voltage of an embedded (e-SiGe in the source and drain region) p-MOSFET under negative gate bias. Here, we account the passivity of the silicon dangling bonds by the free hydrogen and its diffusion into the oxide region and the activation energy of the Si-H bond process depends on the hydrogen concentration. The trap concentration as a function of time for bulk p-MOSFET and e-SiGe p-MOSFET is compared. We shall discuss in detail the inuence of NBTI on the ac/dc characteristics of strain-engineered p-MOSFETs.
Sufi Zafar - One of the best experts on this subject based on the ideXlab platform.
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Recovery study of negative bias Temperature Instability
Microelectronic Engineering, 2009Co-Authors: Miaomiao Wang, Sufi Zafar, James H. StathisAbstract:In this work, we report a study of negative bias Temperature Instability (NBTI) recovery in high-k/metal-gate p-channel field effect transistors (pFETs) with different interfaces. New results on the dependence of recovery on interface, stressing voltage (V"s), stressing Temperature and stressing time (t"s) are shown.
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A Model for Negative Bias Temperature Instability in Oxide and High κ pFETs
2007 IEEE International Conference on Integrated Circuit Design and Technology, 2007Co-Authors: Sufi ZafarAbstract:A model for the negative bias Temperature Instability (NBTI) is proposed. Unlike previous empirical models, this model is derived from physics principles. The model attributes NBTI to de-passivation of SiO2/Si interface and its two distinguishing features are: application of statistical mechanics to calculate de-passivated site density increase as a function of stressing conditions and the assumption that the hydrogen diffusion in oxide is dispersive. The model is verified using published NBTI data for SiO2/poly, SiON/W and HfO2/W pFETs. A comparison between high κ and conventional oxide is made.
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The negative bias Temperature Instability in MOS devices: A review
Microelectronics Reliability, 2005Co-Authors: James H. Stathis, Sufi ZafarAbstract:Abstract Negative bias Temperature Instability (NBTI), in which interface traps and positive oxide charge are generated in metal–oxide–silicon (MOS) structures under negative gate bias, in particular at elevated Temperature, has come to the forefront of critical reliability phenomena in advanced CMOS technology. The purpose of this review is to bring together much of the latest experimental information and recent developments in theoretical understanding of NBTI. The review includes comprehensive summaries of the basic phenomenology, including time- and frequency-dependent effects (relaxation), and process dependences; theory, including drift–diffusion models and microscopic models for interface states and fixed charge, and the role of nitrogen; and the practical implications for circuit performance and new gate-stack materials. Some open questions are highlighted.
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statistical mechanics based model for negative bias Temperature Instability induced degradation
Journal of Applied Physics, 2005Co-Authors: Sufi ZafarAbstract:A physics based model for negative bias Temperature Instability (NBTI) induced degradation is proposed. Like previous models, this model attributes NBTI to depassivation of Si–H bonds at the SiO2∕Si interface. The two distinguishing features of the proposed model are: (i) statistical mechanics is applied to calculate the decrease in interfacial Si–H density as a function of stressing conditions, and (ii) hydrogen diffusion in the oxide is assumed to be dispersive and the diffusing species is identified with the positively charged hydrogen ion (Hi+). The model assumes that as Hi+ diffuses away from the interface into the oxide, interfacial and bulk traps are created. Based on these model assumptions, an equation for the threshold voltage shift (ΔVt) is derived as a function of stressing time, oxide field, Temperature, oxide thickness, and initial Si–H density at the interface. The model predicts that ΔVt would increase with a power law dependence at earlier stressing times and would saturate at longer time...
G Groeseneken - One of the best experts on this subject based on the ideXlab platform.
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positive and negative bias Temperature Instability on sub nanometer eot high k mosfets
International Reliability Physics Symposium, 2010Co-Authors: Marc Aoulaiche, Ben Kaczer, Robin Degraeve, Philippe Roussel, J Franco, T Kauerauf, Lars Ake Ragnarsson, Joshua Tseng, Thomas Hoffmann, G GroesenekenAbstract:For the first time, positive and negative bias Temperature Instability (P/NBTI) mechanisms in sub-nanometer EOT devices are investigated in this study. It is shown that PBTI degradation in sub-nanometer EOT devices occurs by interface degradation, additionally to the oxide bulk trap filling which is the dominant mechanism in over 1nm EOT devices. For NBTI, interface degradation remains as the main mechanism in sub-nano EOT devices, and additional high contribution of the high-k bulk defects can increase the degradation below 6A EOT.
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negative bias Temperature Instability nbti in sio2 and sion gate dielectrics understood through disorder controlled kinetics
Microelectronic Engineering, 2005Co-Authors: B Kaczer, V I Arkhipov, M Jurczak, G GroesenekenAbstract:The acceleration of Negative Bias Temperature Instability (NBTI) in oxynitride gate dielectrics is explained within the framework of disorder-controlled hydrogen kinetics. Nitrogen is assumed to introduce deeper localized hydrogen states in gate oxide film, thus increasing the dispersion of hydrogen transport. The dispersion parameter is linked with the Temperature-dependent NBTI power-law exponent, while hydrogen hopping frequency is inferred from the Temperature dependence of NBTI power-law prefactor. NBTI exponents up to 0.5 are explained by transport of charged hydrogen.
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Temperature dependence of the negative bias Temperature Instability in the framework of dispersive transport
Applied Physics Letters, 2005Co-Authors: Ben Kaczer, Robin Degraeve, G Groeseneken, V I Arkhipov, N Collaert, M GoodwinAbstract:Negative bias Temperature Instability (NBTI) is studied in multiple-gate field-effect transistors with an ultrathin gate oxide. It is observed that the threshold voltage shift in these devices follows a power-law function of time, with the exponent depending linearly on Temperature. An analytic model is proposed that explains this Temperature dependence by dispersive diffusion of hydrogen in the bulk of the gate oxide. Based on both the experimental data and the model, it is concluded that NBTI is an inherently non-Arrhenius process.
