TRANSMISSION ELECTRON-MICROSCOPY ANALYSIS OF A TINX SUBSTOICHIOMETRIC CVD COATING

The TiN(x) square 1-x substoichiometric chemical vapour deposited titanium nitride coatings have been studied in an early work by means of high-resolution X-ray emission spectroscopy. It was found that a strong vacancy-induced peak was present in the Ti K emission band. Its intensity can be correlated to the 1-x vacancy concentration deduced from nuclear reaction spectroscopy and X-ray diffraction. This relationship is linear if 0 less-than-or-equal-to 1-x less-than-or-equal-to 0.3. If 1-x is higher than 0.3, an anomalous behaviour occurs which is expected to be due to microstructure change. For this purpose, transmission electronic studies of a Ti N0.57 square 0.43 layer have been developed. The most striking result of this work is the existence of many stacking faults. These defects are extrinsic ones and the stacking fault energy is about 3.5 mJ m-2. Their density seems to depend on their distance from the substrate-coating interface. Further investigations are needed to confirm this assumption.