Formation of boron-doped silicon wires and control of dopant concentration using zinc, SiCl4 and BCl3

Abstract

We synthesized boron-doped silicon wires (whiskers) in a gas phase reduction reaction of SiCl4 with zinc vapor. BCl3 was introduced into the reactor as a boron source, and we varied the concentration ratio of B/Si in the gas phase. The formed wires had an electrical resistivity in the range of 10–3 to 101 Ω cm, depending on the ratio of BCl3 to SiCl4 in the gas phase. The ratio of B/Si in the silicon wires was not directly proportional to that in the gas phase, suggesting a non-linear incorporation process of dopant during the vapour-liquid-solid growth. Comparison of our data with published studies using gold catalysts to form doped semiconductor nanowires showed a lower incorporation efficiency of dopant atoms from the gas phase when using the zinc catalyst in vapour-liquid-solid growth.