STRUCTURE CHARACTERIZATION OF PLASMA-DEPOSITED TIN COATINGS

The plasma-assisted chemical vapour deposition of TiN on steel, silicon and glass substrates from a gaseous mixture of TiCl4, N2 and H-2 has been studied. The crystallinity and density of the TiN coatings were affected by the r.f. discharge power density. X-ray diffraction revealed that the films have a strong (200) orientation which increases on increasing the discharge power density, and scanning electron micrographs of the TiN films show that the columnar structure becomes more dense. By increasing the discharge power density, the coating microhardness increases up to a maximum, after which it decreases. This effect is attributed to the different chlorine content of the films, which shows a minimum when the microhardness is maximum.