Influence of gas phase composition on the growth of silicon nanowires in Si – H – Cl system

The dependence of the growth rate of silicon nanowires (NWs) on the gas phase composition in the open chemical system SiCl4 – H2 has been experimentally established. It was determined that with increasing concentration of SiCl4 the growth rate of NWs passes through a maximum, and at high concentrations of silicon tetrachloride gas-phase etching of crystals and substrate is possible. A direct correlation between the coefficient of thermal conductivity of the catalyst metal and the NWs growth rate has been established. It is shown that the observed course of the dependence of the NWs growth rate on the gas phase composition is due to the reversibility of the chemical reaction between SiCl4 and H2. The model determining the thermodynamic conditions of stable growth of Si NWs is considered.