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We have measured the physical properties and resistivity of nickel germanide thin films formed by the rapid thermal annealing of nickel metal on p-type germanium substrates. Rutherford back scattering and high-resolution electron diffraction confirm that the stoichiometry of the resulting nickel germanide film corresponds to NiGe and has an orthorhombic unit cell with dimensions comparable to that of bulk samples. Transmission electron microscopy shows a poly-crystalline film structure with grain size > 0.1 μm. The resistivity values for films annealed in the range 350°C-500°C are comparable to those of metal silicides. Measurements of the specific contact resistance suggest that values approaching 2 × 10-7 Ω.cm2 can be realized using NiGe formed on heavily doped p-type germanium.