Infrared laser annealing at a variety of wavelengths (10.0–13.0 &mgr;m) was performed under room temperature for cubic silicon carbide(3C-SiC) films after N-ion implantation by using a free electron laser with features of wide-range tunability, ultrashort pulse operation(∼10 ps),and intense peak power(∼MW).Infrared absorption spectroscopy indicated that the annealing at 12.6 &mgr;m, which corresponds to the absorption peak of Si–C stretch mode, was effective for removing the crystalline damage induced by the ion implantation. On the other hand, Hall effect measurements showed an increase of carrier density for samples annealed at around 10.4 &mgr;m, whereas the absorption was weak at this wavelength. This important result is most likely attributed to the activation of N donors caused by the direct excitation of a local vibration mode associated with N atoms in the SiC matrix. ©1997 American Institute of Physics.