Vertical Growth of Individual Single-Walled Carbon Nanotubes on Silicon and SiO₂ Substrates

Individually isolated single-walled carbon nanotubes (SWNTs) have been successfully grown vertically on a substrate by chemical vapor deposition with methane and Fe or Co catalysts. Vertical growth is obtained when the growth temperature was high, 900–1000°C, and the tube diameter is large, 2–5 nm. Vertically grown SWNTs are short, ranging from several tens to 300 nm, which are useful for use as tips of a field emission or probe microscope. Fullerene encapsulation has been achieved directly in vertical SWNTs on a substrate.