Annealing effect on microstructure and mechanical properties of magnetron sputtering Ti-Si-C thin film

To investigate the influence of temperature on nucleation and growth of Ti₃SiC₂, Ti-Si-C thin films were deposited by magnetron sputtering from elemental targets of Ti, Si and C on Si(100) and Al ₂O₃ substrates at temperature <200°C. Subsequently, the as deposited films were annealed in vacuum at 800, 950, 1100 and 1200°C respectively. The as deposited films consisted of amorphous TiC, amorphous Si and free C, as determined by X-ray diffraction and X-ray photoelectron spectroscopy. Annealing in vacuum <950°C resulted in improved crystallinity of TiC and formation of SiC_x and Ti₅Si ₃ phases. However, the Ti₃SiC₂ phase forms in films at 1100°C owing to the increase in Si diffusion coefficient. Moreover, the evolution of hardness and elastics modulus with annealing temperatures was determined by nanoindentation. The results showed a continuous decline of film hardness with increasing annealing temperature due to the formation of Ti ₃SiC₂ and Ti₅Si₃ phases.