Growth of Ultrahigh Density Vertically Aligned Carbon Nanotube Forests for Interconnects

Abstract

We present a general catalyst design to synthesize ultrahigh density, aligned forests of carbon nanotubes by cyclic deposition and annealing of catalyst thin films. This leads to nanotube forests with an area density of at least 10(13) cm(-2), over 1 order of magnitude higher than existing values, and close to the limit of a fully dense forest. The technique consists of cycles of ultrathin metal film deposition, annealing, and immobilization. These ultradense forests are needed to use carbon nanotubes as vias and interconnects in integrated circuits and thermal interface materials. Further density increase to 10(14) cm(-2) by reducing nanotube diameter is possible, and it is also applicable to nanowires.

A Survey of Carbon Nanotube Interconnects for Energy Efficient Integrated Circuits

“…Presently, the realization of good electrical contacts with metallic electrodes remains a challenge. This is particularly problematic for vertical interconnects where the bottom electrode acts both as a support for the catalytic growth of CNTs and as an electrical contact [67,119]. Another major roadblock comes from the fact than one ideally desires to inject current alongside the axis of the CNT to create a so-called end-bonded contact to the CNTs, which requires a perfect control over the quality of the interface between open-ended CNTs and metal [68].…”

“…These reduced performances can be explained by two main factors: (1) the quality of the CNTs produced by CCVD, which is a relatively lowtemperature process compared to arc-based processes; and (2) the non-ideal packing density of CNTs in integrated interconnects. The latter was much improved by increasing the CNT growth density in the 10 13 cm -2 range [67,119], but it is however inherently limited by the tortuosity of the CNTs produced by CCVD. Even after liquid-induced compaction of the CNT bundles, the packing density of CNTs in interconnect structures is still rather low.…”

“…below 450 o C) with the ability to control nanotube dimensions, density (i.e. up to 10 13 CNTs cm -2 ) and patterning at specific locations [72], [73], [74], [75], [67], [119]. However, the design of catalyst to control nanotube chirality and especially for metallic nanotubes is very challenging [75], [76].…”

Robofurnace: A semi-automated laboratory chemical vapor deposition system for high-throughput nanomaterial synthesis and process discovery

“…For example, a frenzy of research activity has focused on synthesis of carbon nanotubes (CNTs) and graphene, because these nanostructures exhibit outstanding mechanical, electrical, thermal, and optical properties, [3][4][5][6][7][8][9] and could enable novel bulk materials. However, integration of these and other nanostructured materials into commercial products has been limited by the rate at which laboratory demonstrations can be validated for commercial production with quality control.…”

Szerkezeti tényezők hatása a vezető polimerek termoelektromos tulajdonságaira

“…A kialakuló szerkezetben a szén nanocsövek nem vagy nem teljes felületükön tapadnak össze, nagy szabad térfogatot (a teljes térfogat ~97%-a) hagyva ezáltal a szőnyeg szerkezetben. [48,141] A MWCNTA-k elektrokémiai jellemzését a munka későbbi célját, azaz a MWCNTA/P3HT-kompozitok elektrokémiai előállítását szem előtt tartva végeztük. Így az oldószer kiválasztásánál a megfelelő nedvesítésen túl azt is figyelembe vettük, hogy abban jó minőségű, stabil P3HT létrehozására legyen lehetőség.…”