The deposition behavior of silicon films during hot-wire chemical vapor deposition (HWCVD) was studied based on the concept of the two-step growth: the generation of charged silicon nanoparticles in the gas phase and their incorporation into films. If the charged crystalline silicon nanoparticles generated in the gas phase during HWCVD are made to be incorporated into films, microcrystalline silicon films can be obtained at such a low temperature as to be deposited on a flexible substrate of polyethylene terephthalate (PET). Besides, the deposition would be affected by the electric bias applied to the substrate. This possibility was studied in this paper. Electric biases of +150, 0, and -150 V were applied to the substrates of stainless steel and PET maintained at similar to 90 degrees C during silicon HWCVD under 0.6 Torr at a filament temperature of 1700 degrees C. The growth rate on stainless steel at biases of +150 and -150 V was higher than that of the zero bias, whereas the growth rate on PET was higher at a bias of -150 V and lower at a bias of +150 V than that of the zero bias. (C) 2008 Elsevier B.V. All rights reserved.