1. Modeling and Evaluation of High-Speed Signal propagation in Local, Intermediate and Global Interconnects A. Yamilov, M. Koledintseva and J. Drewniak

2. Increasing chip productivity & performance Scaling down feature size Increasing chip area Packing efficiency Decrease of size of Transistors versus Interconnects Reduced cost Reduced switching delay Reduced area Reduced power consumption Reduced cost Increased latency Signal quality degradation Increased power consumption

3. International Technology Roadmap for Semiconductors (ITRS):interconnects Aspect ratio Increased resistivity Decreased T-conductivity Signal integrity

4. Scaling Down M1 Interconnects: Challenges Material issues:  frequency dependence of conductivity  surface and grain scattering Fabrication issues Interconnect functionality (signal integrity) New physics  Temperature effects (heat dissipation)  Quantum effects

5. Increase of Copper Resistivity in Nano-Interconnects From S.Im, N.Srivastava, K.Banerjee, and K.Goodson, “Thermal Scaling Analysis of Multilevel C/Low-k Interconnect Structures in Deep Nanometer Scale Technologies”, Proc. 22th Int. VLSI Multilevel Interconnect Conf. (VMIC), Oct. 3-6, Fremont, CA, pp. 525-530, 2005.

6. EMI and Signal Integrity Challenges Increase of interconnect density: –Decrease of element size and separation –Change of interconnect aspect ratios Increase of clock frequency –Temperature dependences of material parameters (conductivities and permittivities) Complex 3D interconnect morphology –Complexity of coupling

7. Scaling Down M1 Interconnects: Modeling Approaches Macroscopic models for temperature- and size-dependent material parameters: d.c.conductivity and permittivity Equivalent lumped-element circuits Extraction of RLC parameters from the macroscopic material parameters

8. Longer-Term Solution for Global/Intermediate Interconnects: THz Interconnects Frequencies in the 10 12 Hz range Wide signal bandwidth Same materials: Cu/SiO 2 Critical challenges Development of on-chip THz active elements (sources/amplifiers/modulators/detectors/etc.) Geometry optimization: impedances, losses, dispersions, signal reliability, crosstalk, etc