Growth of β-SiC nanowires on Si(100) substrates by MOCVD using nickel as a catalyst

摘要

We have deposited β-SiC nanowires on nickel-covered Si(100) substrates using a single molecular precursor at deposition temperature in the range of 800-1000℃ by metalorganic chemical vapor deposition (MOCVD) method and analyzed their surface and structural characteristics. Nickel played an important role in a catalyst as growing β-SiC nanowires. Dichloromethylvinylsilane (CH_2CHSiC(CH_3)Cl_2) was used as a single molecular precursor without any carrier or bubbler gas. The working pressure was fixed at about 50 mTorr, and the growth of β-SiC nanowires was carried out for 0.5-3 h. SEM images clearly showed that straight nanowires were randomly grown on the substrate with a high density. The lengths of the nanowires were up to several micrometers and their diameters were about 30-50 nm depending on deposition temperature. In order to identify their structure and composition, analyses of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM) combined with energy dispersive X-ray (EDX) were performed. XRD data showed a well-crystallized structure with highly oriented nanowires to (111) and (200) planes. Through TEM and EDX analyses as well as XPS study, we can suggest that as-deposited β-SiC nanowires are wrapped with very thin carbon outer layer, and the wire was grown to [111] direction with well-crystallized structure. This means that our SiC nanowires can be one of the candidate materials for both nanoelectronic device applications and a field emitter due to carbon-rich composition.