The Hot Wire (HW) Cell method was applied to grow epitaxial Si films at a substrate temperature of 200 o C. C 2 H 2 gas was added to this system and C containing epitaxial Si films were also obtained. After annealing the films at 600-700 o C, the vibration mode at 607 cm - 1 , which indicated the presence of the C atoms located at the Si substitutional sites, was observed in Fourier transform infrared absorption and Raman scattering spectroscopy. The X-ray diffraction peak of the annealed films shifted to a greater extent compared to the substrate, which indicated the decrease in the lattice constant of the epitaxial layer. The carbon composition was controlled by changing the partial pressure of the C 2 H 2 gas and we successfully obtained 0.8 at.% substitutional carbon composition.