Intrinsic limits governing MBE growth of Ga-assisted GaAs nanowires on Si(111)

• Published in: Journal of crystal growth Vol. 364; pp. 118 - 122
• Main Authors: Giang, Le Thuy Thanh, Bougerol, C., Mariette, H., Songmuang, R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2013; Elsevier
• Subjects: A1. Diffusion; A1. Low dimensional structures; A1. Nanostructures; A3. Molecular beam epitaxy; Atomic properties; B2. Semiconducting gallium arsenide; Condensed Matter; Cross-disciplinary physics: materials science; rheology; Diffusion; Diffusion rate; Droplets; Exact sciences and technology; Gallium; Gallium arsenide; Materials Science; Methods of crystal growth; physics of crystal growth; Methods of deposition of films and coatings; film growth and epitaxy; Molecular beam epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Nanoscale materials and structures: fabrication and characterization; Nanowires; Other topics in nanoscale materials and structures; Physics; Quantum wires; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; B2. Semiconducting gallium arsenide; A3. Molecular beam epitaxy; A1. Low dimensional structures; A1. Diffusion; A1. Nanostructures; Gallium arsenides; Gallium; Growth rate; Desorption; Nanostructures; III-V compound; Size effect; Growth mechanism; Molecular beam epitaxy; Droplets; Nanowires; Diffusion; Nanostructured materials; Quantitative chemical analysis; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2012.11.032

Diffusion-enhanced and desorption-limited growth regimes of Ga-assisted GaAs nanowires were identified. In the latter regime, the number of vertical NWs with a narrow length distribution was increased by raising the growth temperature. The maximum axial growth rate, which can be quantified by the supplied rate of As atoms, is achieved when a dynamical equilibrium state is maintained in Ga droplets i.e. the number of impinging As atoms on the droplet surface is equivalent to that of the direct deposited Ga atoms combining with the diffusing ones. The contribution of Ga diffusion to the wire growth was evidenced by the diameter-dependent NW axial growth rate. ► Diffusion-enhanced and desorption-limited growth regimes of Ga-assisted GaAs nanowires on Si(111) were identified. ► The vertical alignment of nanowires with a narrow length distribution was improved by raising the growth temperature. ► The maximum axial growth rate is achieved when a dynamical equilibrium state is maintained in Ga droplets. ► The contribution of Ga diffusion to the wire growth was evidenced by the diameter-dependent nanowire axial growth rate.