Effect of nitrogen flow rate on the mechanical properties of CVD-deposited SiCN thin films

Silicon carbonitride (SiCN) thin films were deposited on p-Si (100) substrates with different N-2 flow rates using SiC and Si3N4 powder precursors by chemical vapour deposition. To investigate the structural, vibrational and mechanical properties, the SiCN thin films were characterized by atomic force microscopy, Raman spectroscopy, X-ray diffraction (XRD), Fourier transform infrared and nanoindentation techniques. The XRD results reveal nanocrystals embedded with amorphous networks in the SiCN thin films. An increase in the ID/IG ratio with an increase in the N-2 flow rate indicated the increase of sp3 bonds in the SiCN thin film. The hardness (H), Young's modulus (E), plasticity index (H/E) and (H-3/E-2) increase with an increase in the N-2 flow rate.