[en] The investigation of hard carbon coatings resulting from a simultaneous nitrogen ion implantation process in an oil diffusion pumped vacuum chamber is described. The thin surface layer system produced is a good example for studying the depth profiling of light elements up to charge number 20 by elastic recoil detection analysis (ERDA) in a Bragg ionization chamber. The characterization of the surfaces at different conditions by ERDA depth profiling and the measurement of the correlated wear and friction behaviour allow optimization of the technological conditions for simultaneous carbon deposition and nitrogen implantation. (Author)