SiNW synthesis by vapor-liquid-solid (VLS) growth mechanism has been reported by many authors but a deep understanding of the key factors affecting the nanowire growth is still lacking. Here, we report a thorough investigations of the SiNW growth by employing silicon substrates with different crystal orientations and surface preparation using Au thin film as a catalyst. We observed that the activity of the Au particles strongly depends on the crystal orientation and the substrate surface preparation significantly affects the properties of SiNWs. We found that the density and growth rate of nanowires is different in a temperature dependent growth on Si(100) from Si(111). We found that the density and growth rate of nanowires is different at different crystal orientations of the substrates. We have grown nearly uniform diameter and micrometer long SiNWs by using Si(2)H(6) as a source gas in low pressure chemical vapor deposition around eutectic temperature. The length of the SiNWs can be controlled mainly by varying the growth time. (c) 2008 Elsevier B.V. All rights reserved.