Abstract The influence of Ge incorporation on the structural phase transformation of ZrO 2 films was investigated with the aim to control the resulting dielectric properties. For this reason, Ge-doped ZrO 2 thin films were prepared by atomic oxygen beam deposition at 225 °C. Admixture of low Ge concentrations (3–6.2 at.%) stabilizes the tetragonal ZrO 2 phase, and concurrently increases the permittivity to a maximum value of 37.7. Structural analysis shows that the permittivity enhancement can be explained by the increase of the tetragonal distortion upon Ge doping. The tetragonal phase is stable upon post-deposition high temperature annealing up to 1050 °C under N 2.