Circuit Modeling and Performance Analysis of Multi-Walled Carbon Nanotube Interconnects

• Published in: IEEE transactions on electron devices Vol. 55; no. 6; pp. 1328 - 1337
• Main Authors: Li, Hong, Yin, Wen-Yan, Banerjee, Kaustav, Mao, Jun-Fa
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-06-2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analytical models; Applied sciences; Bundles; Carbon nanotube (CNT); circuit model; Contact resistance; Copper; Delay; Delays; Density; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Integrated circuit interconnections; Integrated circuit modeling; Integrated circuits; interconnect; Multi wall carbon nanotubes; multi-walled CNT (MWCNT); Nanotubes; Performance analysis; Resistance; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal delay; Single wall carbon nanotubes; single-walled CNT (SWCNT); Wire; Performance evaluation; VLSI circuit; Carbon nanotubes; Compact design; Modeling; interconnect; single-walled CNT (SWCNT); Signal delay; multi-walled CNT (MWCNT); Multiwalled nanotube; Interconnection; Integrated circuit; Equivalent circuit; circuit model; Carbon nanotube (CNT); Delay time; performance analysis
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2008.922855

Metallic carbon nanotubes (CNTs) have received much attention for their unique characteristics as a possible alternative to Cu interconnects in future ICs. Until this date, while almost all fabrication efforts have been directed toward multiwalled CNT (MWCNT) interconnects, there is a lack of MWCNT modeling work. This paper presents, for the first time, a detailed investigation of MWCNT-based interconnect performance. A compact equivalent circuit model of MWCNTs is presented for the first time, and the performance of MWCNT interconnects is evaluated and compared against traditional Cu interconnects, as well as Single-Walled CNT (SWCNT)-based interconnects, at different interconnect levels (local, intermediate, and global) for future technology nodes. It is shown that at the intermediate and global levels, MWCNT interconnects can achieve smaller signal delay than that of Cu interconnects, and the improvements become more significant with technology scaling and increasing wire lengths. At 1000- global or 500- intermediate level interconnects, the delay of MWCNT interconnects can reach as low as 15% of Cu interconnect delay. It is also shown that in order for SWCNT bundles to outperform MWCNT interconnects, dense and high metallic-fraction SWCNT bundles are necessary. On the other hand, since MWCNTs are easier to fabricate with less concern about the chirality and density control, they can be attractive for immediate use as horizontal wires in VLSI, including local, intermediate, and global level interconnects.