Polycrystalline diamond films (1 to 10 μm grain diameter) are successfully deposited by electron beam activated chemical vapour deposition technique using glow discharge/plasma generated electron beam from 3 to 4 vol% CH3COCH3 in H2. The growth rates of film depositions are 4 μm/h at 533 Pa pressure and at relatively low substrate (silicon) temperatures (550 to 600°C). Crystallinity, morphology, and quality of the diamond films are studied by X-ray diffraction, scanning electron microscopy, and laser Raman spectroscopy techniques, respectively. The use of electron bombardment in the presence of H and OH plays a dominant role for etching the non-diamond component in the film and facilitating the growth of a stable phase of tetrahedrally coordinated carbon (diamond) films at lower temperatures.