GeO2 was proposed as valuable passivation layer at the surface with Ge to integrate oxide with high dielectric constant in Ge-based logic devices. Hence, the identification of the defects present at different Ge/GeO2 interfaces becomes a mandatory issue to predict the electrical features of devices based on such materials. High sensitive electrically detected magnetic resonance measurements were performed to study the microstructure of defects occurring at such an interface. The influence of the oxidation temperature on the electrically active paramagnetic traps was investigated.