The effects of high dose carbon and nitrogen implantations into copper on the type of chemical bonds and stoichiometry of the formed C-N phases are described. The results are compared with those obtained after nitrogen implantation into diamond like carbon (DLC) layers. The striking difference between the two experiments is the stoichiometry of covalently bonded C-N phase which corresponds to C2N or to C3N3.7 for N implantation into DLC and C and N implantation into copper, respectively.