Interconnect Delay Model for Wide Supply Voltage Range Repeater Insertion in Sub-22 nm FinFET Technologies

Abstract

Energy efficiency has been a primary focus over the past decade. Energy saving techniques such as dynamic voltage and frequency scaling, power gating, and many-core systems-on-chip, have been extensively studied. These techniques, however, struggle to deliver desired energy efficiencies while failing to exploit wide supply voltage ranges in mobile sub-22 nm microprocessors. Additionally, scaling exacerbates these problems, resulting in significant parasitic interconnect resistances. A major factor that limits dynamic wide voltage ranges and frequency scaling is the inability to optimize interconnect to support a wide voltage range from nominal to subthreshold voltages. The primary contribution of this work is the analysis and optimization of repeater insertion for wide supply voltage range applications. A closed-form delay model supporting wide voltage ranges is developed to enable this analysis. The model supports an ultra-wide voltage range from nominal voltages to deep subthreshold voltages, and repeater size multipliers up to 640 times the minimal size. The model is validated with SPICE using a commercial 14 nm FinFET transistor model for interconnect resistances and capacitances up to, respectively, 2 k and 2 pF. The model exhibits good accuracy across the entire parameter space, with the worst case error ranging from −3.5% to 7.3% (−12% to 13% in the subthreshold region) for single stage delays, and from −17% to 9% (−15% to 17% in the subthreshold region) for long interconnect lines with repeaters. Challenges to repeater insertion are also evaluated based on the proposed model.

RF and Crosstalk Analysis of Copper and MLGNR Interconnects Using Different Repeaters in Sub-10 nm Regime

“…Multi-gate transistors generally called Fin-FETs due to their Fin type shape are just structural improvement of traditional CMOS. They demonstrate better gate control over channel current with minimal presence of short channel effects (SCEs) as reported in [5][6][7]. CNFET has attracted attention of many researchers due to use of CNTs as channel material and their novel properties [8].…”