Growth and electrical properties of Al-catalyzed Si nanowires

We report the growth and electrical characterization of small-diameter, Al-catalyzed silicon nanowires. Large quantities of Si nanowires can be grown with a fast growth rate at a low temperature of 520 °C via a vapor-liquid-solid process using Al as catalyst. The use of high H2 partial pressure was found to effectively mitigate the Al catalyst oxidation problem, and higher SiH4 partial pressure was found to produce smaller diameter nanowires. Electrical measurements show that small diameter (d<∼25 nm) Al-catalyzed nanowires behave as p-type semiconductors with good gate response, while larger diameter Al-catalyzed nanowires behave as degenerately Al-doped semiconductors.