We prepared hydrogenated silicon thin films at various gas pressures and gas flow rates by hot-wire chemical vapor deposition (HWCVD) and investigated the influence of these parameters on their structural properties using X-ray diffraction and Raman spectroscopy. Deposition rate showed a maximum at gas pressure of 500 mTorr and increased with increasing the silane gas flow rate F(SiH4). Gas pressure at which transition from amorphous to microcrystalline occurred increased with increasing the F(SiH4). The mean crystallite size and crystalline volume fraction increased monotonously with the increase in the gas pressure and the decrease in the F(SiH4). (c) 2005 Elsevier B.V. All rights reserved.