Control of gold surface diffusion on si nanowires.
Silicon nanowires (NW) were grown by the vapor-liquid-solid mechanism using gold as the catalyst and silane as the precursor. Gold from the catalyst particle can diffuse over the wire sidewalls, resulting in gold clusters decorating the wire sidewalls. The presence or absence of gold clusters was observed either by high angle annular darkfield scanning transmission electron microscopy images or by scanning electron microscopy. We find that the gold surface diffusion can be controlled by two growth parameters, the silane partial pressure and the growth temperature, and that the wire diameter also affects gold diffusion. Gold clusters are not present on the NW side walls for high silane partial pressure, low temperature, and small NW diameters. The absence or presence of gold on the NW sidewall has an effect on the sidewall morphology. Different models are qualitatively discussed. The main physical effect governing gold diffusion seems to be the adsorption of silane on the NW sidewalls.
den Hertog
Martien I
MI
Laboratoire d'Etude des Matériaux par Microscopie Avancée, CEA/DRFMC, CEA-Grenoble, 17 rue des Martyrs, 38052 Grenoble Cedex 9, France. martien.den-hertog@cea.fr
Rouviere
Jean-Luc
JL
Dhalluin
Florian
F
Desré
Pierre J
PJ
Gentile
Pascal
P
Ferret
Pierre
P
Oehler
Fabrice
F
Baron
Thiery
T
D000327:Adsorption; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004058:Diffusion; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012821:Silanes / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
D046911:Macromolecular Substances; D012821:Silanes; D012825:Silicon