Selective growth of vertically aligned double- and single-walled carbon nanotubes on a substrate at 590 °C

Abstract

Vertically aligned double- and single-walled carbon nanotubes (DWNTs and SWNTs) were synthesized on a substrate at 590 °C by hot-filament chemical vapor deposition. An optimized combination of iron and aluminum layers as the catalyst resulted in iron particles ranging from 1-5 nm floating in an aluminum matrix after annealing. Selective synthesis of DWNTs and SWNTs from such particles was achieved by adjusting the dilution ratio of acetylene that was used as the source gas. The yield of DWNTs among all CNTs was as high as 81%, while that of SWNTs was almost 100%. The diameter distribution of DWNTs was narrow, with a standard deviation of about 12%.

A Review of Double-Walled and Triple-Walled Carbon Nanotube Synthesis and Applications

“…This threshold sensitively varied when the purity of the sputtering target was changed, but the same trend was observed. The selective growth of DWNTs was also achieved by optimizing the Fe concentration of the carbon source [113].…”

Growth of carbon nanotubes at temperatures compatible with integrated circuit technologies

“…However, in many cases demonstrating low temperature growth, the large area reproducibility and/or the quality of the nanotubes are not fully reported, or the growth results in carbon nanofibres (instead of nanotubes) [4][5][6][7] , with many internal material defects which affect their use as interconnects, requiring further annealing or opening up of inner-layer conduction channels via mechanical polishing 8,9 . There has been a singular reporting of growth of SWNTs at low temperatures (below 400°C) 10 , non-uniform and over small areas, whilst follow-up attempts used temperatures in the region of 600°C 11 . There have been no further reports of such growth being repeated or made industry-compatible.…”

Fast atom bombardment onto vertically aligned multi-walled carbon nanotube bumps to achieve low interconnect resistance with Au layer

“…The CNT bumps were then grown on the Au electrodes by the CVD method. In this process, acetylene was introduced as a source gas under a 500 to 600°C atmosphere [26]. MWNTs were used, and they were vertically aligned using this method.…”