Influence of ambient gas on the growth kinetics of Si nanocones

Multi-segment silicon nanocones were designed and fabricated to investigate their growth kinetics. We found the ambient gas influenced the growth rates of Si nanocones remarkably. The axial growth rate increased with the total pressure of ambient gas, finally approaching saturation. Meanwhile the radial growth rate also increased with the total pressure but decreased with hydrogen content. A model was developed to study the growth kinetics by combining the effects of Langmuir adsorption, silane decomposition, and hydrogen coverage on the surface of SiNCs, which agreed with the experimental results. This paper also demonstrated the controllable cone angles by the ambient gas. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3494111]