The formation of furnace processed Te- and Ge-based ohmic contacts on n-GaAs was investigated using Rutherford Backscattering Spectroscopy and electrical measurements. Contact resistivities obtained with the Ni/Au/Te metallization were comparable to those of the standard Ni/AuGe scheme, the lowest value for both metallizations being 5.10−6Qcm2. The onset of ohmicity of the Au/Te scheme varied from 480°C to 550°C by changing the Au/Te thickness ratio. The diffusion characteristics of the contacting metals were studied on GaAs as well as on SiO2 substrates. Arguments in favor of the model explaining the nature of the contacts by the formation of a heterojunction-like structure are adduced.