The advantage of the ion beam assisted deposition technique lies in the good control of process parameters such as film atomic composition, purity, density and adhesion, in addition to improved surface cleanliness of the substrate. A machine for combined ion implantation and physical vapour deposition (Joule effect and electron-gun) has recently been built at the Trento laboratories. It was designed with emphasis on easy and clean operation. To test the performance of the machine, with specific reference to the composition and structure of the coatings produced, we worked on a relatively well known system, titanium nitride, which was deposited with an electron gun in the presence of a nitrogen ion beam (characterized by an energy of 30 keV) and a nitrogen atmosphere. Samples of different stoichiometry were produced and characterized by scanning electron microscopy, X-ray diffraction and Auger electron spectroscopy. The results show, as expected, the important role played by the ion beam impinging on the sample.