Taguchi methodology to grow single-walled carbon nanotubes on silicon wafer

Single-walled carbon nanotubes (SWCNTs) were grown by ethanol chemical vapor deposition (ECVD) and growth parameters were optimized using the Taguchi optimization technique. Optimized parameters such as catalyst, spin coating speed, temperature and flow rate of carrier gas are found to be cobalt (Co) and 5% nickel (Ni), 2000 rpm, 900°C, and 100 sccm (argon and 5% hydrogen), respectively. SWCNTs obtained with optimized parameters on SiO (100) substrate show length that ranges form several hundreds of nanometers to a few micrometers and diameters in 1 nm to 3 nm range. Spin coating at 2000 rpm and drying at 8000 rpm are the desired speeds to form the nanosized metal particles for growing small diameter dense network of SWCNTs. Morphological differences between SWCNTs grown with different parameters are studied and discussed by atomic force microscopy and scanning electron microscopy.