Silicon carbide (SiC) nanorods and microcrystals were synthesized with controlled structure through a two-step reaction scheme. Carbon nanotubes (CNTs). were first grown by the thermal decomposition of C2H2 over a Fe/Co metal catalyst loaded on a Si(100) wafer surface. The grown CNTs were then reacted with tetramethylsilane (TMS) to form beta-SiC nanorods or microcrystals. SiC nanorods were observed when CNTs reacted with TMS at 1100degreesC in an IR-induced heating chemical vapor deposition (CVD) reactor, whereas SiC microcrystals were formed at 1250degreesC in an rf-induced-heating CVD reactor. Higher temperature and longer time were favorable for the growth of good quality SiC crystals. The blueshift of the PL spectra was observed from the SiC nanorods and SiC microcrystals. The structural change of CNTs in the growth was discussed in this work. (C) 2003 American Vacuum Society.