Abstract: The 700.degree. C./4 min. rapid thermal anneal described in the prior art for converting amorphous Si to polycrystalline Si can be reduced to a temperature range of from 550.degree. C. to 650.degree. C. This is accomplished by depositing a very thin discontinuous film of a nucleating site forming material over the amorphous Si prior to rapid thermal anneal. Furthermore, by selectively depositing the material in a pattern, only that amorphous Si beneath the deposited pattern is caused to crystallize during annealing, while the remaining areas of amorphous Si remain in the amorphous state.