We have investigated the formation of carbon nanotubes (CNTs) by the SiC surface decomposition method using transmission electron microscopy. When the SiC specimen was annealed at 1250oC for 1.0 h in an ultra-high vacuum, carbon nanofibers (CNFs) as well as CNTs were formed on the SiC(000-1) surface. However, when the specimen was annealed in oxygen, CNFs were not formed on the surface. These results indicate that oxygen is necessary for the CNT formation using the SiC surface decomposition method.
