MEV METAL-ION IMPLANTATIONS FOR BURIED LAYER FABRICATION IN SILICON

A review is given of MeV ion beam synthesis of deep-buried compound la yers in silicon with special emphasis on the formation of buried metal silicide layers. The formation of buried NiSi2 layers by 6 MeV Ni hig h dose implantation and annealing is described in detail. The evolutio n of Ni concentration profiles, the dose-dependent interaction of impl anted metal atoms and radiation damage, and the formation of the silic ide phase are treated up to overstoichiometric doses. Layer formation during the anneal is described for both pure Ni implanted (111)Si wafe rs and for Ni irradiated Si/Si3N4/(100)Si silicon-on-insulator structu res, leading to heteroepitaxial Si/NiSi2/Si systems and to Si/Si3N4/Si /NiSi2/Si multilayer sequences, respectively. The latter experiments p ossibly imply a new application of MeV implantations for the formation of buried layers.