Nickel monosilicide is an intermetallic compound formed out of nickel and silicon. Like other nickel silicides, NiSi is of importance in the area of microelectronics.
Nickel monosilicide can be prepared by depositing a nickel layer on silicon and subsequent annealing. In the case of Ni films with thicknesses above 4 nm, the normal phase transition is given by Ni<sub>2</sub>Si at 250 ðC followed by NiSi at 350 ðC and NiSi<sub>2</sub> at approximately 800 ðC. For films with an initial Ni thickness below 4 nm a direct transition from orthorhombic Ni<sub>2</sub>Si to epitaxial NiSi<sub>2âÂÂx</sub>, skipping the nickel monosilicide phase, is observed.
Several properties make NiSi an important local contact material in the area of microelectronics, among them a reduced thermal budget, low resistivity of 13âÂÂ14 üé÷cm and a reduced Si consumption when compared to alternative compounds.