Novel approach to fabricating carbon nanotube via interconnects using size-controlled catalyst nanoparticles

Abstract

We propose a new approach to fabricating carbon nanotube (CNT) vias, which uses preformed catalyst nanoparticles to grow CNTs. A newly-designed impactor provided size-classified catalyst particles, and a new deposition system injected them into via holes down to 40 nm in diameter. The resultant CNT-via resistance was 0.59 Ω for 2-µm vias, which is the lowest ever reported, improved from the previous studies using catalyst films. The improvement resulted from higher-density CNTs grown in the via holes by employing the nanoparticle catalyst.

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

“…The imperfect contact resistance R mc can range from zero to hundreds of kilo-Ohms for different growth processes. Recently, as demonstrated in [11], [12], and [19], R mc in MWCNT could be very small compared to the total resistance.…”

“…5) and geometrical parameters (shown in Table I) used in Section III are employed for SWCNT bundles at the global, intermediate, and local interconnect levels, respectively. The resistance, inductance, and quantum capacitance of SWCNT can be calculated based on (7), (12), and (13), respectively (with channel number = 2). For densely packed SWCNT bundles, their electrostatic capacitance has slight difference with the capacitance of Cu wire [17].…”

“…However, due to its simple structure, SWCNTs can be modeled more easily than MWCNTs. In fact, while most CNT interconnect fabrication efforts have targeted MWCNTs [9]- [12], nearly all modeling efforts are focused on the analysis of isolated SWCNTs [13] or SWCNT bundles [14]- [17]. These studies indicate that compared to Cu wires, SWCNT bundles can provide significant improvement in delay for long (global and intermediate levels) interconnects.…”

“…However, more recently, it has been found that multiple shells in an MWCNT can contribute to conductance if proper end contacts can be made. In [11], [12], and [19], properly contacted MWCNTs have been implemented to achieve low resistance with the contribution of inner shells. Moreover, low resistances achieved in these works also indicate that the contact resistance between metal and the nanotube can be relatively small.…”

Crosstalk overshoot/undershoot analysis and its impact on gate oxide reliability in multi-wall carbon nanotube interconnects

“…The imperfect contact resistance R C can range from zero to 100 k for different growth processes. Recently, as demonstrated in [2,9], and [10], R C in MWCNT could be very small compared to the total resistance.…”