Influence of post-heat treatment over structural network and mechanical properties of carbon (C)-incorporated CVD TiCN thin-film coating

In this experimental work, a p-type c-Si (100) substrate with 8 x 8 x 2 mm dimension was taken for TiCN thin-film coating deposition. The whole deposition process was carried out by chemical vapor deposition (CVD) process. The Si substrate was placed within the CVD chamber at base pressure and process pressure of 0.75 and 500 mTorr, respectively, in the presence of TiO2 (99.99% pure) and C (99.99% pure) powder mixture. Later on, quantity of C powder was varied for different set experiments. The deposition of TiCN coating was carried out in the presence of N-2-H-2-TiCl4-CH3CN gas mixture and 600 celcius of fixed temperature. The time for deposition was fixed for 90 min with 10 and 5 celcius min(-1) heating and cooling rate, respectively. Later on, heat treatment process was carried out over these deposited TiCN samples to investigate the changing characteristics. The heat treatment was carried out at 800 celcius within the CVD chamber in the absence of any gas flow rate. The morphological properties of heat-treated samples have been improved significantly, evidence is observed from SEM and AFM analyses. The structural analysis by XRD has been suggested, upgradation in crystallinity of the heat-treated film as it possessed with sharp and higher intensity peaks. Evidence has been found that the electrochemical properties are enhanced for heat-treated sample. Raman spectroscopy shows that the intensity of acoustic phonon modes predominates the optic phonon modes for untreated samples, whereas for heat-treated samples, opposite trends have been observed. However, significant degradation in mechanical properties for heat-treated sample has been observed compared to untreated sample.