Selective Synthesis of SiC and SiO x Nanowires by Direct Microwave Irradiation

We report a facile and novel method for the selective growth of SiC and SiO x nanowires by direct microwave irradiation on a Si substrate under atmospheric pressure. Selective synthesis of the amorphous SiO x or crystalline SiC nanowires was achieved by varying the gas composition in the reactor. The proposed method requires a short reaction time (2 min) with no need for vacuum equipment because the reaction is carried out under atmospheric pressure. High-resolution transmission electron microscope images revealed that the SiO x nanowires were amorphous and that the SiC nanowires were crystalline. Raman spectra showed features typical of nano-sized SiC. On the basis of our results, we propose a growth mechanism of SiC and SiO x nanowires synthesized by direct microwave irradiation.