We investigate the structural properties and, in particular, the residual stress of carbon implanted TIN coatings by means of glancing incidence x-ray diffraction and secondary ion mass spectrometry. The coatings were grown by ion beam physical vapor deposition on steel substrates and subsequently implanted at 100 KeV with carbon doses Of 1x10(17) ions/cm(2), 3x10(17) ions/cm(2), 7x10(17) ions/cm(2), respectively. The carbon depth profiles obtained by secondary ion mass spectrometry enable us to choose the more appropriate x-ray beam incidence angles in order to detect the structural variations in proximity of the implanted region. The x-ray results indicate notable variations both in the crystallinity and in the residual stress and such modifications depend on the carbon dose and penetration depth.