Structural transformation of carbon nanotubes to silicon carbide nanorods or microcrystals by the reaction with different silicon sources in rf induced CVD reactor

摘要

Silicon carbide (SiC) nanorods and microcrystals were synthesized through a two-step reaction scheme. Carbon nanotubes (CNTs) were first grown over metal catalyst-loaded Si(100) wafer surface by thermal decomposition of C_2H_2. The grown CNTs were then reacted with a gas mixture of SiH_4 and C_3H_8 or tetramethylsilane (TMS) to form beta-SiC nanostructures. The growth of SiC nanorods was observed when CNTs were reacted with SiH_4 and C_3H_8, whereas SiC microcrystals were formed when reacting the CNTs with TMS. However, the SiC nanostructures were not grown without CNTs. The diameter of the nanorods was around six times larger than that of the mother nanotubes. The nanorods were crystalline beta-SiC with the diameter of 300-400 nm and grew along (111) direction. The structural transformation of CNTs to SiC nanorods or to microcrystals during the reaction was discussed in this paper.