A Survey of Carbon Nanotube Interconnects for Energy Efficient Integrated Circuits

2017 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)

Amoroso³

et al. 2017

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Abstract-In this study, we suggest a hierarchical model to investigate the electrical performance of carbon nanotube (CNT)-based interconnects. From the density functional theory, we have obtained important physical parameters, which are used in TCAD simulators to obtain the RC netlists. We then use these RC netlists for the circuit-level simulations to optimize interconnect design in VLSI. Also, we have compared various CNT-based interconnects such as single-walled CNTs, multi-walled CNTs, doped CNTs, and Cu-CNT composites in terms of conductivity, ring oscillator delay, and propagation time delay.

Section: Simulation Resultsmentioning

confidence: 99%

“…In this work, we present a hierarchical simulation approach to studying of CNT-based interconnect performance [7][8][9]. The transport properties of CNT interconnects are first evaluated by ab-initio methods.…”

Section: Introductionmentioning

confidence: 99%

Atoms-to-circuits simulation investigation of CNT interconnects for next generation CMOS technology

Lee

2017 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)

Amoroso³

et al. 2017

Self Cite

“…Atomically thin, ballistic transport, large electron MFP and highly conductive carbon-based materials such as carbon nanotubes (CNTs) provide compelling advantages for the next generation of on-chip interconnects [3], [4]. CNTs are also listed as one of the future materials for advanced technology nodes based on IRDS 2017 report [5].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Pt-Salt-Doped-Standalone- Multiwall Carbon Nanotubes for On-Chip Interconnect Applications

IEEE Trans. Electron Devices

Chen

Ramos

et al. 2019

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In this paper, we investigate by combining electrical measurements with an atomistic-to-circuit modeling approach, the conductance of doped stand-alone multi-wall carbon nanotubes (MWCNTs) as a viable candidate for the next-generation of back-end-of-line (BEOL) interconnects. Ab-initio simulations predict a doping-related shift of the Fermi level, which reduces shell chirality variability and improves electrical resistivity up to 90% by converting semiconducting shells to metallic. Electrical measurements of Pt-salt doped CNTs provide up to 50% of resistance reduction, which is a milestone result for future CNT interconnect technology. Moreover, we find that defects and contacts introduce additional resistance, which limits the efficiency of doping and are the primary cause for the mismatch between theoretical predictions and experimental measurements on doped CNTs. Index Terms-Carbon nanotube, defective CNTs, doped CNTs, local on-chip interconnects, individual CNT growth, doping process of CNT, CNT contact resistance.

“…Because of strong sp 2 bonding between carbon atoms, CNT is much more resistant to electromigration (EM) and can sustain significantly larger current densities than Cu [5]. Furthermore, self-heating problem is a concern on deeply scaled Cu interconnects whereas CNTs have long ballistic electronic transport length ∼1µm, making them have higher electrical and thermal conductivities and thus capable of carrying high current density with virtually no heating thanks to its 1D electronic structure [6]- [8].…”

Section: Introductionmentioning

confidence: 99%

Variability Study of MWCNT Local Interconnects Considering Defects and Contact Resistances--Part I: Pristine MWCNT

Chen

IEEE Trans. Electron Devices

Lee

et al. 2018

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In this paper, an enhanced compact model of multiwalled carbon nanotube (MWCNT) interconnects while considering defects and contact resistance is proposed. Based on the atomistic-level simulations, we have found that defect densities impact MWCNT resistance and ultimately their electrical performance. Furthermore, we have computed by atomisticlevel simulations the end-contact resistance between single-wall carbon nanotube (SWCNT) and Palladium (Pd) electrode to mimic the Pd-CNT end-contact resistance of each CNT shell in MWCNT. We have developed an advanced shell-by-shell model to include various parameters such as shell diameter, shell chirality, defects on each shell, and connectivity of each shell to endcontacts. We run Monte Carlo simulations to perform variability studies on each of these parameters to understand the electrical performance variation on MWCNT interconnects. We present simulation results to convey the critical impact of variations. The impact of doping on MWCNT variability in the form of Fermi level shift will be addressed in Part II of this paper.