Interconnects for nanoscale MOSFET technology: a review

Abstract

In this paper, a review of Cu/low-k, carbon nanotube (CNT), graphene nanoribbon (GNR) and optical based interconnect technologies has been done. Interconnect models, challenges and solutions have also been discussed. Of all the four technologies, CNT interconnects satisfy most of the challenges and they are most suited for nanometer scale technologies, despite some minor drawbacks. It is concluded that beyond 32 nm technology, a paradigm shift in the interconnect material is required as Cu/low-k interconnects are approaching fundamental limits.

Enhancement of Multiwalled Carbon Nanotubes’ Electrical Conductivity Using Metal Nanoscale Copper Contacts and Its Implications for Carbon Nanotube-Enhanced Copper Conductivity

“…4 This diversity offers potential for their use in microelectronic devices. 5,6 In particular, it has been suggested that when Cu/ low-k interconnects approach fundamental limits then CNTs are the "most suited for nanometer scale technologies"; 7 however, we have recently demonstrated that when contact effects (including underlying surface contamination) are taken into account, there may be a lower limit that CNT-based devices can reliably operate. 8 In our studies on individual MWCNTs and junctions between MWCNTs, we have previously employed tungsten contacts.…”

“…Achiral single-walled CNTs (SWCNTs) are metallic, , but the rest are either small or moderate band gap semiconductors, while multiwalled CNTs (MWCNTs) are usually zero-gap metals . This diversity offers potential for their use in microelectronic devices. , In particular, it has been suggested that when Cu/low- k interconnects approach fundamental limits then CNTs are the “most suited for nanometer scale technologies”; however, we have recently demonstrated that when contact effects (including underlying surface contamination) are taken into account, there may be a lower limit that CNT-based devices can reliably operate …”

Ultra‐Thin Chips with Printed Interconnects on Flexible Foils

“…Results were ≈4.2 × 10 −8 Ωm, equivalent to the conductivity of 40% bulk Ag, revealing the highest conductivity in comparison with conventional interconnect materials such as Cu/low‐k, carbon nanotube (CNT) and graphene nanoribbon (GNR). [ 26 ] Nevertheless, the additional resistance (≈30 Ω each) in series leads to small voltage drop across them and thus reduced the effective drain bias across the MOSFET channel. Based on the measured resistance of printed bonding lines, we have theoretically calculated the voltage drops on each resistor load when connected in series and summarized in Table S1 (Supporting Information).…”

Geometric Shape Induced Small Change of Seebeck Coefficient in Bulky Metallic Wires

“…As high-strength materials, they have been extensively applied as frameworks and covers for most manmade products. As excellent electrical conductors, metallic wires are used as power lines, and Al, Cu, and W thin films are applied as interconnects in most conventional electronic circuits and in state-of-the-art integrated circuits [ 1 , 2 ]. Au, Ag, Pt, Cu, and Al thin films are intensively applied as electrodes in lab-on-a-chip systems [ 3 ], micro-electro-mechanical systems (MEMS) [ 4 ], and nano-electro-mechanical systems (NEMS) [ 5 ], as well as in a variety of quantum electronic devices [ 6 , 7 , 8 , 9 , 10 ], and novel medical devices embedded in the human body [ 11 , 12 , 13 , 14 ].…”