Homogeneous Heteroepitaxial NiSi2 Formation on (100)Si

The mechanism of NiSi2/Si interface formation on (100)Si is examined. The interface roughness between NiSi2 and Si strongly depends on the substrate impurity species. A smooth interface is formed on As-doped Si, but the interface is highly faceted on the {111} plane on BF2-doped Si. The covalent radius of the impurity atoms strongly affects the interface formation. An interfacial distorted layer is observed only at the NiSi2/As-doped Si interface. This distorted layer could reduce the lattice strain between NiSi2 and Si. These results demonstrate the possibility of realizing a homogeneous epitaxial interface.