The Experts below are selected from a list of 534 Experts worldwide ranked by ideXlab platform
Kidon Lee - One of the best experts on this subject based on the ideXlab platform.
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effect of joule heating on electromigration in Dual Damascene copper low k interconnects
International Reliability Physics Symposium, 2017Co-Authors: Kidon Lee, Jinseok Kim, Taeyoung Jeong, Yinghong Zhao, Quan Yuan, Anuj Patel, Zack Tran Mai, Logan H Brown, Steven English, Daniel SawyerAbstract:The effect of Joule heating (JH) on electromigration (EM) was investigated using copper low-k interconnects. We found Black's empirical EM model works at a very wide stress conditions (I = 0.03 mA ∼ 3.5mA), where the temperature rise by JH ranges from 0°C to 240°C. EM modeling parameters were found to be 1.05eV and 1.4 for EM Ea and n, respectively. Extensive failure analysis and FEM simulations were carried out to understand the EM failure mode at various JH conditions and provide guidelines for the usage of JH-assisted EM test method and design-reliability rules.
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statistical study for electromigration reliability in Dual Damascene cu interconnects
IEEE Transactions on Device and Materials Reliability, 2004Co-Authors: Kidon LeeAbstract:This paper summarizes results from recent studies on electromigration (EM) reliability of Cu Dual-Damascene interconnects using a statistical approach. First, mass transport in Cu Damascene structure was discussed, where the activation energies for oxide, porous MSQ (methylsilsesquioxane), and organic polymer dielectrics were found to be in the range of 0.8-1.0 eV, suggesting mass transport is dominated by interfacial diffusion at the Cu and SiN/sub x/ cap-layer interface regardless of the dielectric material. Then the impact of low-k inter-layer dielectrics on EM characteristics was investigated by measuring the critical product of current density and conductor length, (jL)/sub c/. Compared with oxide, the weaker mechanical strength of low-k dielectrics reduces (jL)/sub c/ due to less confinement and a smaller back flow stress gradient /spl Delta//spl sigma//L in Cu/low-k interconnects. Extrinsic failure due to interfacial delamination was observed in Cu/organic polymer interconnects, which caused further decrease in (jL)/sub c/. Complementing EM tests, Monte Carlo simulation was developed based on the weakest link approximation to separate the bimodal failure distribution into two indiviDual lognormal distributions and deduce the characteristics of the weak-mode (early) and the strong-mode failures. Failure analysis using FIB confirmed the bimodal failure behavior with void formation at the cathode via bottom found to be responsible for the early failures.
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electromigration reliability issues in Dual Damascene cu interconnections
IEEE Transactions on Reliability, 2002Co-Authors: E T Ogawa, Kidon Lee, Volker BlaschkeAbstract:Electromigration studies on Cu interconnects are reviewed. Some history and more recent results are discussed along with a description of the present interpretations of the active mass transport mechanisms involved in Cu electromigration. The issue of the Dual-Damascene process and its potential effect on EM reliability is described with special focus on the peculiarities of the Dual-Damascene interconnect architecture compared to more conventional subtractively etched Al-based interconnects. Experiments performed on Dual-Damascene interconnects that highlight electromigration reliability issues such as early failure, a tentative explanation for via electromigration failure, and the Blech effect, are summarized. Emphasis is placed on an experimental methodology that uses large interconnect ensembles in a multi-link configuration. Such a large scale study of nearly 10000 interconnects has shown statistical evidence of bimodal failure behavior consistent with the presence of a weak and strong failure mode, which have been identified as voiding, respectively, within the via and the trench at the cathode end of an interconnect. A multi-link approach has also demonstrated a length-dependent distribution of failures that yields a (j/spl middot/L)/sub c/ product value of about 9000 A/cm in Dual-Damascene Cu/oxide interconnections and is consistent with mass transport that is controlled by the presence of extended defects within Cu such as grain boundaries, interfaces, and/or surfaces. The study of Dual-Damascene Cu has demonstrated the importance of statistics in analyzing EM reliability.
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electromigration critical length effect in cu oxide Dual Damascene interconnects
Applied Physics Letters, 2001Co-Authors: Kidon Lee, E T Ogawa, Hideki Matsuhashi, Patrick R Justison, Volker BlaschkeAbstract:Electromigration tests at temperatures between 340 and 400 °C and current densities between 1.0 and 3.0 MA/cm2 have been performed to determine the temperature dependence of the critical length effect in 0.5-μm-wide Cu/oxide Dual-Damascene interconnects with 0.1 μm silicon nitride (SiNx) passivation. A focused-ion-beam-induced contrast imaging technique is used to locate failure sites of critical length test structures. Statistical analysis [E. T. Ogawa et al., Appl. Phys. Lett. 78, 18 (2001)] yields a threshold-length product (jL)c, of 3700 A/cm, and a temperature dependence is not observed within the temperature range 340–400 °C.
M H Lin - One of the best experts on this subject based on the ideXlab platform.
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void nucleation and growth contributions to the critical current density for failure of cu vias
International Reliability Physics Symposium, 2009Co-Authors: A S Oates, M H LinAbstract:We investigate the critical current density for electromigration failure, j c , as a function of voiding failure mode for Cu Dual Damascene vias. We demonstrate experimentally the variation of (jL) product with via failure mode showing that it is not possible to characterize vias by a single (jL). We suggest that, in general, j c for failure is determined by the sum of void nucleation and growth components, and we present a model for j c based on these concepts.
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electromigration failure distributions of cu low k Dual Damascene vias impact of the critical current density and a new reliability extrapolation methodology
IEEE Transactions on Device and Materials Reliability, 2009Co-Authors: A S Oates, M H LinAbstract:We examine the effects of void morphology and critical current density (jc) on the electromigration failure distributions of Cu/low-k Dual-Damascene vias. Cu Dual-Damascene vias exhibit multiple modes of electromigration-induced voiding, and reliability is strongly dependent on the morphology of voids. We have developed a model of failure for dc and pulsed dc currents that allows prediction of failure time distributions for vias, taking into account void morphology. We obtain good agreement between the model predictions and experimental data for all observed void morphologies. The model demonstrates that while the concept of ldquoimmortalityrdquo is valid for indiviDual conductors, it cannot be applied to eliminate failure of all nominally identical conductors in large sample sizes that are typical of integrated circuits. We experimentally confirm the existence of resistance increase failures for test populations of nominally identical conductors stressed below the sample average jc. Moreover, failure time distributions for vias exhibit distortion from lognormal and saturation in the vicinity of jc, but they are predictable for all values of j. New reliability extrapolation procedures are required for accurate projection of electromigration lifetimes close to jc. We suggest that the description of the effects of jc on failure distributions of vias discussed here is generally valid irrespective of the choice of conductor and barrier layer materials, and we demonstrate equivalent characteristic behavior of electromigration failure time distributions for both Al and Cu interconnects. Our results also indicate that, in general, accurate modeling of jc for conductor failure requires consideration of both nucleation and growth phenomena, with the relative contribution of each process to jc being dependent on the voiding failure mode.
Volker Blaschke - One of the best experts on this subject based on the ideXlab platform.
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electromigration reliability issues in Dual Damascene cu interconnections
IEEE Transactions on Reliability, 2002Co-Authors: E T Ogawa, Kidon Lee, Volker BlaschkeAbstract:Electromigration studies on Cu interconnects are reviewed. Some history and more recent results are discussed along with a description of the present interpretations of the active mass transport mechanisms involved in Cu electromigration. The issue of the Dual-Damascene process and its potential effect on EM reliability is described with special focus on the peculiarities of the Dual-Damascene interconnect architecture compared to more conventional subtractively etched Al-based interconnects. Experiments performed on Dual-Damascene interconnects that highlight electromigration reliability issues such as early failure, a tentative explanation for via electromigration failure, and the Blech effect, are summarized. Emphasis is placed on an experimental methodology that uses large interconnect ensembles in a multi-link configuration. Such a large scale study of nearly 10000 interconnects has shown statistical evidence of bimodal failure behavior consistent with the presence of a weak and strong failure mode, which have been identified as voiding, respectively, within the via and the trench at the cathode end of an interconnect. A multi-link approach has also demonstrated a length-dependent distribution of failures that yields a (j/spl middot/L)/sub c/ product value of about 9000 A/cm in Dual-Damascene Cu/oxide interconnections and is consistent with mass transport that is controlled by the presence of extended defects within Cu such as grain boundaries, interfaces, and/or surfaces. The study of Dual-Damascene Cu has demonstrated the importance of statistics in analyzing EM reliability.
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electromigration critical length effect in cu oxide Dual Damascene interconnects
Applied Physics Letters, 2001Co-Authors: Kidon Lee, E T Ogawa, Hideki Matsuhashi, Patrick R Justison, Volker BlaschkeAbstract:Electromigration tests at temperatures between 340 and 400 °C and current densities between 1.0 and 3.0 MA/cm2 have been performed to determine the temperature dependence of the critical length effect in 0.5-μm-wide Cu/oxide Dual-Damascene interconnects with 0.1 μm silicon nitride (SiNx) passivation. A focused-ion-beam-induced contrast imaging technique is used to locate failure sites of critical length test structures. Statistical analysis [E. T. Ogawa et al., Appl. Phys. Lett. 78, 18 (2001)] yields a threshold-length product (jL)c, of 3700 A/cm, and a temperature dependence is not observed within the temperature range 340–400 °C.
A S Oates - One of the best experts on this subject based on the ideXlab platform.
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void nucleation and growth contributions to the critical current density for failure of cu vias
International Reliability Physics Symposium, 2009Co-Authors: A S Oates, M H LinAbstract:We investigate the critical current density for electromigration failure, j c , as a function of voiding failure mode for Cu Dual Damascene vias. We demonstrate experimentally the variation of (jL) product with via failure mode showing that it is not possible to characterize vias by a single (jL). We suggest that, in general, j c for failure is determined by the sum of void nucleation and growth components, and we present a model for j c based on these concepts.
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electromigration failure distributions of cu low k Dual Damascene vias impact of the critical current density and a new reliability extrapolation methodology
IEEE Transactions on Device and Materials Reliability, 2009Co-Authors: A S Oates, M H LinAbstract:We examine the effects of void morphology and critical current density (jc) on the electromigration failure distributions of Cu/low-k Dual-Damascene vias. Cu Dual-Damascene vias exhibit multiple modes of electromigration-induced voiding, and reliability is strongly dependent on the morphology of voids. We have developed a model of failure for dc and pulsed dc currents that allows prediction of failure time distributions for vias, taking into account void morphology. We obtain good agreement between the model predictions and experimental data for all observed void morphologies. The model demonstrates that while the concept of ldquoimmortalityrdquo is valid for indiviDual conductors, it cannot be applied to eliminate failure of all nominally identical conductors in large sample sizes that are typical of integrated circuits. We experimentally confirm the existence of resistance increase failures for test populations of nominally identical conductors stressed below the sample average jc. Moreover, failure time distributions for vias exhibit distortion from lognormal and saturation in the vicinity of jc, but they are predictable for all values of j. New reliability extrapolation procedures are required for accurate projection of electromigration lifetimes close to jc. We suggest that the description of the effects of jc on failure distributions of vias discussed here is generally valid irrespective of the choice of conductor and barrier layer materials, and we demonstrate equivalent characteristic behavior of electromigration failure time distributions for both Al and Cu interconnects. Our results also indicate that, in general, accurate modeling of jc for conductor failure requires consideration of both nucleation and growth phenomena, with the relative contribution of each process to jc being dependent on the voiding failure mode.
S Selberherr - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Electromigration in Dual-Damascene Interconnect Structures
2020Co-Authors: R L De Orio, H Ceric, S Carniello, S SelberherrAbstract:We have analyzed the stress build-up and vacancy dynamics due to material transport caused by electromigration in Dual-Damascene interconnect structures. Our model incorporates all relevant driving forces for material transport with a complete integration of mechanical stress in connection with microstructural aspects. First, it is shown that the addition of redundant vias can be effective in increasing the interconnect lifetime, although the spacing between the vias can have a significant impact on such an approach. Then, we discuss the importance of grain boundaries in providing triple point intersections, where the combination of high vacancy concentration and high stress is likely to cause void nucleation
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Electromigration Failure Development in Modern Dual-Damascene Interconnects
2020Co-Authors: R L De Orio, H Ceric, J Cervenka, S SelberherrAbstract:Abstract-The electromigration failure development in typical copper Dual-Damascene interconnect structures is analyzed based on numerical simulations. The origin of the lognormal distribution of electromigration times to failure is investigated. Also, electromigration-induced void formation and evolution in advanced 0.18 µm Dual-Damascene lines are simulated and the results are compared with experiments. It is shown that the lognormal distribution of the grain sizes leads to lognormal distributions of the electromigration lifetimes. Moreover, the void nucleation sites and main features of void development are highly dependent on the microstructure of the interconnect lines
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TCAD Solutions for Submicron Copper Interconnect
2020Co-Authors: H Ceric, R L De Orio, J Cervenka, S SelberherrAbstract:Abstract- The demanding task of assessing a long range interconnect reliability can only be achieved by combination of experimental and TCAD methods. A basis for TCAD tools is a sophisticated physical model which takes into account the microstructural characteristics of copper. In this work a general electromigration model is presented with a special focus on the influence of grain boundaries and mechanical stress. The possible calibration and usage scenarios of electromigration tools are discussed. The physical soundness of the model is proven by three-dimensional simulations of typical Dual-Damascene structures used in accelerated electromigration testing
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electromigration failure in a copper Dual Damascene structure with a through silicon via
Microelectronics Reliability, 2012Co-Authors: R L De Orio, H Ceric, S SelberherrAbstract:Electromigration induced failure development in a copper Dual-Damascene structure with a through silicon via (TSV) located at the cathode end of the line is studied. The resistance change caused by void growth under the TSV and the interconnect lifetime estimation are modeled based on analytical expressions and also investigated with the help of numerical simulations of fully three-dimensional structures. It is shown that, in addition to the high resistance increase caused by a large void, a small void under the TSV can also lead to a significant resistance increase, particularly in the presence of imperfections at the TSV bottom introduced during the fabrication process. As a consequence, electromigration failure in such structures is likely to have bimodal characteristics. The simulation results have indicated that both modes are important to be considered in order to obtain a more precise description of the interconnect lifetime distribution.
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a comprehensive tcad approach for assessing electromigration reliability of modern interconnects
IEEE Transactions on Device and Materials Reliability, 2009Co-Authors: H Ceric, R L De Orio, J Cervenka, S SelberherrAbstract:The demanding task of assessing long-time interconnect reliability can only be achieved by combination of experimental and technology computer-aided design (TCAD) methods. The basis for a TCAD tool is a sophisticated physical model which takes into account the microstructural characteristics of copper. In this paper, a general electromigration model is presented with special focus on the influence of grain boundaries and mechanical stress. The possible calibration and usage scenarios of electromigration tools are discussed. The physical soundness of the model is proved by 3-D simulations of typical Dual-Damascene structures used in accelerated electromigration testing.
