Mn 5 Ge 3 can be used as a ferromagnetic contact material to fabricate spintronic devices. Here, we show that Mn 5 Ge 3 can be fabricated with a simple germanidation process by evaporating Mn on undoped and doped Ge on Si followed by a thermal annealing step to form the ferromagnetic Mn 5 Ge 3 phase. This solid phase preparation of Mn 5 Ge 3 is a robust process with a minor dependence on the annealing parameters. The formation of Mn 5 Ge 3 can be realized using undoped as well as highly doped p-Ge and n-Ge with different doping levels. The interface of Mn 5 Ge 3 is atomically sharp which leads to very low contact resistivities < 1 × 10 −7 Ω cm 2 .