Considerable relaxation of the high internal stresses which arise in HfN thin films during their deposition by a sputtering method has been accomplished through bombarding the films with energetic silicon ions. The internal stresses have been estimated from the measurements of the surface curvature. Our results indicate a relaxation of the internal compressive stresses in the films, which occurs via a transport of the interstitial defects within the thermal spikes created by a post-deposition energetic ion bombardment. The mechanical properties of HfN films before and after the treatment have been studied by depth-sensing indentation technique while the structural analysis has been made using x-ray diffraction, Rutherford backscattering, and Anger electron spectroscopy. Ion bombardment did not affect resistivity of the thin films while improving their plastic properties. (C) 1996 American Institute of Physics.