Our preliminary studies show that covalent solid CNx compounds can be synthesized by high dose nitrogen implantation into carbon thin films. 100 keV N+ ions at a dosage of 1.2×1018 cm−2 were implanted at different temperatures. The samples were evaluated by x‐ray photoelectron spectroscopy (XPS), x‐ray diffraction analysis, and Fourier transform infrared absorption spectroscopy (FTIR). N(1s) core level line XPS analyses show the existence of two different N(1s) bonding states, corresponding to the nitrogen of the C–N covalent bonding state and free state nitrogen, respectively. More importantly, it can be clearly seen that the content of C–N covalent bonding state in the samples is increased with increasing of the implanting temperature of samples. When implantation was performed at 500 °C, C(1s) XPS studies show the existence of three different C(1s) bonding states, corresponding to graphite, i‐carbon, and the carbon of C–N covalent bonding state, respectively, and FTIR analyses indicate that there is an absorption band near 2200 cm−1 assigned to the C≡N covalent bonding. © 1995 American Institute of Physics.