Chromium nitride thin films were deposited by RF reactive unbalanced magnetron sputtering on (100) Si single-crystal or glassy carbon substrates. The characteristics of the thin films were measured by Rutherford backscattering spectroscopy, X-ray diffractometry, and scanning electron microscopy. From the results of the above measurements, it was found that our samples were stoichiometric chromium nitride thin films. The chemical bonding state was estimated using the results of the Fourier-transform infrared spectroscopy. A peak attributed to the Cr-N bond was observed at around 380 cm(-1), and it could be obtained with any beam splitter and atmosphere. Furthermore, the influence of residual stress was also investigated. Residual stresses of CrN thin films, which were calculated from their strains, were quite low. (C) 2011 The Japan Society of Applied Physics