Morphological Evolution of Silicon Nanowires Grown by Chemical Vapor Deposition
Morphological evolution of Si nanowires (Si-NWs) grown on Si (001) substrates is explored. The Si-NWs are fabricated by nanoscale Au-Si island-catalyzed rapid thermal chemical vapor deposition. The Au-Si islands (10-50 nm in dia.) are formed by deposition of Au thin film (1.2-3.0 nm) at room temperature and followed by annealing at 700oC. The Si-NWs are grown by exposure them to a mixture of gasses of SiH4 and H2. We found a critical thickness of the Au film for Si-NW nucleation at a given growth condition. Also, we observed variation in the growth rate and the dimension of the NWs depending on the growth pressure and temperature. The resulting NWs are ~30-100nm in diameter and ~0.4-5.0μm in length. Most of the NWs were aligned along the <111> direction. The morphological and dimensional evolution of the Si-NWs is discussed in terms of kinetics (atomic diffusion mechanism) and energetics (surface and interface energies).
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
D. W. Kwak et al., "Morphological Evolution of Silicon Nanowires Grown by Chemical Vapor Deposition", Solid State Phenomena, Vols. 124-126, pp. 1201-1204, 2007