Buried nitride silicon-on-insulator (SOI) structures have been fabricated using the technique of nitrogen ion implantation. The crystallinity of the top silicon film was found to be exceptionally good. The minimum channeling yield, Xmin' was better than 3%. This is comparable to the value observed for single crystal silicon. The buried insulator formed during the anneals has been identified as polycrystalline α-Si3 N4 with numerous silicon inclusions. This nitride, however, has been found to remain amorphous in regions at the center of the implant where the nitrogen concentration exceeds the stoichiometric level of Si3N4. Nitrogen donor formation in the top silicon layer has also been observed.