Study of the growth mechanisms of chromium nitride films deposited by ion plating

The films are obtained by ion plating. Chromium is evaporated by electron beam bombardment in an electrical discharge generated in a pure nitrogen atmosphere. The determination of the number and the energy of the particles impinging on the growing film is the first objective. In particular it is shown that more 90% of the ions impinging on the film are nitrogen ions. When a pure CrN phase is obtained the ratio of the chromium atoms flux to the ions flux is equal to 0.5. The study of the influence of the different deposition parameters on the microstructure and on the mechanical properties constitutes the second part. Nitrogen pressure (p N2 ), substrate bias voltage (V S ), substrate bias current (I S ), substrate temperature (T S ) and evaporation rate (v e ) are taken into account. The composition of the film depends on, p N2 , I S and v e . The structure and the texture appear to be very sensitive to V s . A clear correlation between the texture and the intrinsic stresses is pointed out. The mechanical properties depend principally on I s and V s and are practically independant of T s when it is higher than 350°C.