Carbon coils could be synthesized using C2H2/H2 as source gases and SF6 as an incorporated additive gas under thermal chemical vapor deposition, CVD system. Prior to the carbon coils deposition reaction, two kinds of samples having different combination of Ni catalyst and substrate were employed, namely, a commercially-made Al2O3 ceramic boat with Ni powders and a commercially-made Al2O3 substrate with Ni layer. By using a commercially-made Al2O3 ceramic boat, the synthesis of carbon coils could be enhanced as much as 10 times higher than that of Al2O3 substrate. Furthermore, the dominant formation of the microsized carbon coils could be obtained by using Al2O3 ceramic boat. The surface roughness of the supporting substrate of Al2O3 ceramic boat was understood to be associated with the large scale synthesis of carbon coils as well as the dominant formation of the larger-sized, namely the microsized carbon coils.