Mechanical behavior related to various bonding states in amorphous Si-C-N hard films

A series of amorphous Si-C-N hard films were prepared by an electron cyclotron resonance chemical vapor deposition method. Microstructure characterization revealed that amorphous Si-C-N hard films contained various bonding states. Among them, SiN and SiC bonds played a leading role in determining the microstructure of amorphous Si-C-N hard films. Mechanical measurements showed that the hardness of these films varied between 17 GPa and 28 GPa as a function of the tetramethylsilane flow rate. A close relation between various bonding states and hardness was found. The variation of hardness was dominated by the bond fraction that corresponded to various bonding states. Macroscopic mechanical properties of a material were illustrated from the perspective of microscopic structural characterization.