We have designed a simple-hot wall low pressure chemical vapor deposition (LPCVD) system to grow high quality epitaxial Si films from 550 to 900°C. The epitaxial film has been examined by scan electron microscopy for surface morphology, and by x-ray diffraction and cross-sectional transmission electron microscopy for crystallinity. Its quality has been found comparable to that of the substrate. Reduction of moisture and oxygen in the ambient is critical to the success of the growth at low temperatures. A combination of a leak-tight LPCVD reactor, a high flow rate of 61/min of H2 purge, and a pre-bake at high temperature of 950°C has been used to achieve the reduction of moisture and oxygen. Degraded films form with increasing full width at half maximum of x-ray diffraction peak when a pre-bake at lower temperature is used.