The atomic structure of the NiSi₂-(001)Si interface

The atomic structure of the epitaxial NiSi2-(001)Si interface has been investigated by transmission electron microscopy. Lattice images of cross-sections, taken on a JEOL 200 CX microscope with a point-to-point resolution of 2·4Å, are compared with simulated multislice images and suggest a model of the NiSi2-(001)Si interface which is atomically abrupt with silicon atoms everywhere tetrahedrally coordinated. Diffraction contrast analysis of (001) specimens is used to establish the presence of interfacial dislocations of Burgers vector type α/4〈111〉 which separate crystallographically equivalent domains in the (001) interface and may exist at junctions between (001) and (111) facets. The role of these dislocations, which may relieve misfit strains, and the reasons for the pronounced (111) and (001) faceting in the NiSi2-(001)Si interface are discussed.