High temperature (900℃) rapid thermal annealing is used to crystallize the hydrogenated amorphous silicon films deposited by plasma enhanced chemical vapor deposition ( PECVD ) at low temperatures (120~270℃), which are much lower ranges than the conventional PECVD deposition temperature. The effects of deposition temperature and rapid thermal process are investigated by Raman spectra and X-ray diffraction. After RTA process, two kinds of phenomena are observed. One is that the higher the deposition temperature is, the more difficult the grain growth is. The other effect is that keeping at higher temperature($T_b$) between RTA steps improves the volume fraction of crystallites.