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Proceedings ArticleDOI

Investigating the electro-thermal origin of breakdown in low-K/Cu dielectrics under short duration over stressed pulsed regime

TL;DR: A detailed study of low-K/Cu structures under short duration pulse regime and establish a microscopic understanding of breakdown behavior under high current stressing is presented in this article. But the model is based on extensive experimental study.
Abstract: We present a detailed study of low-K/Cu structures under short duration pulse regime and establish a microscopic understanding of breakdown behavior under high current stressing. Random and anomalous behavior of the breakdown characteristics observed under very fast pulsing conditions are explained through electro-thermal instability. A model based on extensive experimental study has been developed to show switching behavior of a conducting path (short failure) due to meltdown of copper. The dumping of critical energy can lead to permanent damage and leads to an open failure. Established breakdown model has been critically linked to the material behavior and extrapolated to understand the TDDB behavior of the low K dielectric.
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Journal ArticleDOI
TL;DR: In this paper, the authors examine the limit of gate oxide scaling from a reliability point of view, and explore the relative importance of characteristic breakdown time and Weibull slope in lifetime projection, and the possibilities of extending gate oxide beyond the currently predicted limit.
Abstract: In this article, we critically examine the limit of gate oxide scaling from a reliability point of view. The thickness dependence of the characteristic breakdown time (charge) and Weibull slope as well as the temperature dependence of oxide breakdown are measured with emphasis on accuracy. The failure modes of soft and hard breakdown events and their impact on device characteristics are reviewed. Using a two-dimensional reliability analysis, we explore the relative importance of characteristic breakdown time and Weibull slope in lifetime projection, and the possibilities of extending gate oxide beyond the currently predicted limit.

146 citations

Journal ArticleDOI
TL;DR: In this paper, a simple physical model is applied to time-dependent dielectric breakdown failure in ultralow-k(k=2.3) interlevel dielectrics.
Abstract: A simple physical model is applied to time-dependent dielectric breakdown failure in ultralow-k(k=2.3) interlevel dielectrics. The model assumes that failure depends on the probability that an electron will have enough energy to damage the dielectric as it is accelerated in an electric field. It is seen that the characteristic form of the dependence of failure time on voltage or electric field is primarily dependent on the probability of having sufficient energy and not on the precise physical mechanism causing damage. An argument for a log-normal-like failure distribution is also presented.

143 citations

Proceedings ArticleDOI
E.T. Ogawa1, Jinyoung Kim1, G.S. Haase1, Homi C. Mogul1, Joe W. McPherson1 
13 May 2003
TL;DR: In this article, the breakdown and TDDB performance of low-k interconnect dielectrics are observed to degrade with the degree of porosity but the failure kinetics (field acceleration parameter and activation energy) seem to be insensitive to porosity.
Abstract: The reliability physics of low-k interconnect dielectrics is of great interest. Leakage, breakdown and TDDB data are presented for fluorinated silica, porous carbon-doped silica, and very porous carbon-doped silica. The breakdown and TDDB performance of the dielectrics are observed to degrade with the degree of porosity but the failure kinetics (field acceleration parameter and activation energy) seem to rather insensitive to porosity. A percolation model has been developed whereby the pores are treated as defects. The percolation model seems to describe well the observed breakdown and TDDB behavior.

113 citations


"Investigating the electro-thermal o..." refers background in this paper

  • ...interface traps, neutral electron traps, anomalous positive charge) can be exacerbated by copper diffusion, which can be highly temperature sensitive [3-9]....

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  • ..., interconnect for 32nm SoC for future mobile, digital home appliance and automotive products [1, 3-9]....

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  • ...A model based on thermally diffusing copper ions and neutral atoms or the presence of pores (acting as defective sites) predicts that the dielectric degradation accumulates over time and eventually reaches a critical density - a threshold triggering permanent damage [3-9]....

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Journal ArticleDOI
TL;DR: In this article, the authors studied soft breakdown in capacitors and nMOSFETs with 4.5-nm oxide thickness and showed that the SBD detection strongly depends on the test structure area.
Abstract: In this work we have studied soft breakdown (SBD) in capacitors and nMOSFET's with 4.5-nm oxide thickness. It is shown that for larger area devices gate current and substrate current as a function of the gate voltage after SBD are stable and unique curves, but for smaller area devices both currents become lower and unstable. This difference can be explained by the different energy available for discharging in the SBD path. It is shown that the SBD detection strongly depends on the test structure area. In nMOSFET's for positive gate polarity, the large increase in the substrate current at the SBD moment is proposed as a sensitive SBD detector. Two level fluctuations in the gate current are investigated at different voltages and are explained by means of a model where electron capture-emission in the traps of the SBD path induces local field fluctuations causing variations in the tunneling rate across the oxide. In the substrate current directly correlated two-level fluctuations are observed.

101 citations


"Investigating the electro-thermal o..." refers background or methods in this paper

  • ...Correlating Backend Reliability with Gate Oxide Reliability under TDDB stressing Time dependent dielectric breakdown in gate oxide is extensively studied phenomenon [15-16]....

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  • ...[15] F Crupi, R Degraeve, G Groeseneken, Nigam T and Maes H E “On the properties of the gate and substrate current after soft breakdown in ultrathin oxide layers,” IEEE Trans....

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Proceedings ArticleDOI
26 Mar 2006
TL;DR: In this article, a new physical model of time-dependent dielectric breakdown (TDDB) in Cu interconnect dielectrics is proposed, which occurs due to the drift of Cu ions under an electric field E. The authors assumed two possible types of Cu ion drift mechanism, Schottky type or Poole-Frenkel type.
Abstract: A new physical model of time-dependent dielectric breakdown (TDDB) in Cu interconnect dielectrics is proposed. TDDB occurs due to the drift of Cu ions under an electric field E. An activation energy analysis of the leakage current demonstrates that these injected Cu ions affect the conduction mechanism of electrons. The dominant electron conduction mechanism changes from Poole-Frenkel electron current through the Cu barrier dielectrics to Fowler-Nordheim current due to the Cu pile-up at the cathode end. We assumed two possible types of Cu ion drift mechanism, Schottky type or Poole-Frenkel type. The field acceleration model (radicE model) of the Poole-Frenkel type fits both TDDB lifetime and activation energy very well. The TDDB lifetime is proportional to the exponential of the square root of the electric field radicE

90 citations