[en] The production, thermal stability and structure of ion induced defects have been studied by Rutherford backscattering in channeling geometry for the implantation of helium and deuterium in graphite, diamond and silicon carbide with energies of 8 and 20 keV. At the implantation of deuterium and helium ions more defects were measured in graphite than in diamond or silicon carbide at equal experimental conditions. This is due to increased backscattering in graphite, which is caused by the splitting and tilting of crystallites and a local reordering of lattice atoms around defects. At 300 K, Helium produces more defects in all three materials than deuterium with equal depth distribution of defects. The ratio of the defects produced by helium and deuterium agrees very well with the corresponding ratio of the energy deposited in nuclear collisions. In graphite, only small concentrations of deuterium induced defects anneal below 800 K, while in diamond small concentrations of deuterium as well as of helium induced defects anneal mostly below 800 K. This annealing behavior is considered to be due to recombination of point defects. The buildup of helium and deuterium in graphite is different. The trapping of deuterium proceeds until saturation is reached, while in the case of helium trapping is interrupted by flaking. In diamond, deuterium as well as helium are trapped almost completely until at higher fluences reemission starts and saturation is reached. Two desorption mechanisms were identified for the thermal desorption of helium from base-oriented graphite. Helium implanted at low fluences desorbs diffusing to the surface, while for the implantation of high fluences the release of helium due to blistering dominates. The desorption of deuterium from graphite and diamond shows differences. While in graphite the desorption starts already at 800 K, in diamond up to 1140 K only little desorption can be observed. These differences can be explained by the different transport properties of deuterium and hydrocarbons through graphite and diamond. (orig.)