Growth mechanism during silicon epitaxy by photochemical vapor deposition at low temperatures

The growth mechanism of Si epitaxial film at low temperatures on Si(100) by photochemical vapor deposition (photo-CVD) is analyzed theoretically by us ing reaction models both in the gas phase and on the surface. We discuss th ree surface reactions: the growth of Si from SiH3 radicals, the dangling bo nd termination by atomic hydrogen and the abstraction of bonding hydrogen b y SiH3 radicals. The parameters of the surface-reaction model are estimated from the experimental results, assuming that the film structure is determi ned by the hydrogen surface-coverage ratio "theta". The theoretical analysi s explains well the experimental results of the Si films grown under variou s conditions.