Techniques are disclosed for forming a non-planar germanium quantum well structure. In particular, the quantum well structure can be implemented with group IV or III-V semiconductor materials and includes a germanium fin structure. In one example case, a non-planar quantum well device is provided, which includes a quantum well structure having a substrate (e.g. SiGe or GaAs buffer on silicon), a IV or III-V material barrier layer (e.g., SiGe or GaAs or AlGaAs), a doping layer (e.g., delta/modulation doped), and an undoped germanium quantum well layer. An undoped germanium fin structure is formed in the quantum well structure, and a top barrier layer deposited over the fin structure. A gate metal can be deposited across the fin structure. Drain/source regions can be formed at respective ends of the fin structure.