Thin titanium nitride (TiN) films have been prepared by contemporaneous Ti evaporation and 30 keV N-2(+) implantation onto Si(100) wafers, in the presence of a N-2 partial atmosphere. The films have been characterized chemically and compositionally both by Auger electron spectroscopy (AES) and X-ray photoemission spectroscopy (XPS) checking the homogeneity level, the degree of gaseous contamination, the different compounds formed mainly by titanium and their depth distribution. Brillouin scattering measurements allowed determination of the Rayleigh velocity at various angles of incidence. We also found evidence of a Sezawa mode, confined in the overlayer. The films, which consist of a homogeneous outer layer above a relatively wide interface region with the substrate, show ageing effects. On a mesoscopic scale, film structure appears porous.