A combination of low-temperature MeV carbon ion implantation and post high- temperature annealing was used to produce a -SiC buried layer in Si(001). The growth of the -SiC layer and re-growth of the front Si layer upon annealing was monitored by x-ray diffraction and x-ray pole figure measurement. In the samples annealed at a temperature of or higher, the buried -SiC layer has a near-perfect orientation relationship with the substrate. The structure of the front Si layer, interestingly, was modified after annealing, i.e., the forbidden Si(002) diffraction was observed. The orientation relationships among the three layers, i.e., the front Si layer, the -SiC buried layer and the bulk substrate, were also investigated by the x-ray pole figure measurement.