1 / 25

Self-Consistent Analysis of Power, Performance, and Reliability in Copper Interconnects

This paper explores the self-consistent analysis of power, performance, and reliability metrics in copper interconnects. It delves into the challenges posed by interconnect scaling, including resistance and capacitance effects, delays, and power dissipation. The study presents methods to mitigate these issues by comparing technologies such as low-k dielectrics versus traditional materials. Furthermore, it examines the impact of temperature on electrical resistance and electromigration, emphasizing the reliability concerns related to increased current densities. The findings aim to guide further innovations in interconnect design.

tadita
Télécharger la présentation

Self-Consistent Analysis of Power, Performance, and Reliability in Copper Interconnects

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Self-Consistent Power/Performance/Reliability Analysis for Copper Interconnects Bipin Rajendran, Pawan Kapur,Krishna C. Saraswat R. Fabian W. Pease Dept. of Electrical Engineering, Stanford University, CA 94305 Acknowledgement : Office of Naval Research Award # N00014-01-1-0741. MARCO Interconnect Focus Center SLIP, 2004

  2. Interconnect Scaling • Scaling Trends • More wires • Shrinking and more metal levels • Resistance & Capacitance  •  Performance deteriorates • Metrics • Delay • Power dissipation • Cross talk (data reliability) • Bandwidth • Area • Reliability • Mitigating Solutions (Technology) • Al to Cu • lower k: Two Methods From ITRS SLIP, 2004

  3. Metal SiO2 Low-k Si Homogeneous Non-homogeneous Dielectric Technology • Power:Homogeneous • Cross talk:Non-homogeneous • Delay: • local: C (homogeneous) • long distance: RC (Unclear?) SLIP, 2004

  4. Ignored Before Future ALD IPVD C-PVD Self-Consistent Temperature Distribution • Fourier’s Law • Electrical Resistance  [T] • Thermal Coefficient of Resistance • Barrier, Surface Scattering • Number of metal levels • Thermal Resistance  1/keff[T] • Number of metal levels • Via Effect SLIP, 2004

  5. Start with uniform Tn[k] Barrier effect Surface scattering Temperature Copper Resistance Rent’s Rule Length demarcation Heating (q=J2rms ) No: of metal levels, n Via Effect Thermal Resistance, Rth No Tn[k] = Tn[k+1] ? Tn[k+1] Yes n – metal level k - iteration Stop GivenCurrent Density, J.FindTemperature, T? SLIP, 2004

  6. I.D.F Semi - Global Local Global Efficient heat conductors (reduce thermal resistance) Electrical & Thermal Resistance • Rent’s Rule • Wire Length Distribution • RC Wire Delay • Local, Semi-global, Global Demarcation • Number of metal levels • Stack Height • Thermal Resistance • Stack Height • Via Effect Gate Pitch SLIP, 2004

  7. Number of Metal Levels Fluctuations are artifacts of numerical calculations Power, Ground & Clock lines not included SLIP, 2004

  8. Maximum Temperature Rise T  J2RTh T~ 10  T~ 3  SLIP, 2004

  9. Effective Thermal Resistance Rth,eff=Hi / Keff, i Surprising decrease! Wire thickness H ~ 4  Rth,eff ~ 1.5  Keff ~ 3.5  Poor Conductivity of Low-k Rth,eff ~ 3  Keff ~constant High Conductivity of SiO2 SLIP, 2004

  10. Electrical Resistivity-Global Wires Consistent Solution is larger by up to 15% Technology node (nm) SLIP, 2004

  11. Electrical Resistivity-Semi-Global Wires Negligible difference Wire Temperature ~ Substrate T Smaller wire pitch  Larger via density Technology node (nm) SLIP, 2004

  12. Wire Capacitance Ctotal= CIMD+CILD 70% of Ctotal = CIMD IMD is Low-k for both cases Capacitance 1.6  IMD ~ 2  SLIP, 2004

  13. Delay Metric - RC/L2 R/Length ~ 50  C/Length ~1.6  Capacitance advantage of homogeneous is offset by the increased resistance Is that all? Reliability SLIP, 2004

  14. Can Current Density go on Increasing? • Required Current • Integration density • Allowed Current • Electromigration • IR drop in supply voltage • Black’s Law If J  T  MTF SLIP, 2004

  15. Mean Time to Failure Larger Temperature  Lower MTF Non-homogeneous is better. Reliability Cross-talk SLIP, 2004

  16. Is there a consistent solution? • Black’s Law • Joule Heating r - Duty Cycle SLIP, 2004

  17. Joule Heating Black’s Law Consistent Solution Point of intersection is the consistent solution SLIP, 2004

  18. Consistent Solution SLIP, 2004

  19. Conclusion • Consistent Algorithm to estimate • Thermal Profiles • Electromigration constraints • Comparison of Dielectric Technologies • Power, Delay - Homogeneous • Cross-talk, Reliability – Non-homogeneous SLIP, 2004

  20. Thank You SLIP, 2004

  21. Back Up SLIP, 2004

  22. Wire Length SLIP, 2004

  23. Electrical Resistivity - Local Wires Negligible difference Wire Temperature ~ Substrate T Smaller wire pitch  Larger via density SLIP, 2004

  24. Duty Cycle • Higher Duty Cycle •  More heating • JRMS should  to keep MTF same. SLIP, 2004

  25. SiO2 - Low-k Comparison Red lines – SiO2 Delay is larger SLIP, 2004

More Related