Mechanical and optical properties of hard SiCN coatings prepared by PECVD

• Published in: Thin solid films 2004-01, Vol.447 (Complete), p.201-207
• Main Authors: Jedrzejowski, P., Cizek, J., Amassian, A., Klemberg-Sapieha, J.E., Vlcek, J., Martinu, L.
• Format: Article
• Language: English
• Subjects: Mechanical properties; Microstructure; PECVD; SiCN; Spectroscopic ellipsometry
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(03)01057-5

Novel amorphous SiCN coatings are becoming increasingly attractive because of their mechanical, optical and electronic properties. In the present work, SiCN films were fabricated by PECVD from SiH 4/CH 4/N 2/Ar gas mixtures at a temperature of 400 °C. Mechanical properties such as hardness, Young's modulus, friction coefficient and stress were evaluated, respectively, by depth-sensing indentation, pin-on-disk, micro-scratch and curvature methods. Films deposited under optimized conditions exhibited a hardness >30 GPa, Young's modulus >190 GPa, elastic rebound of 85% and a compressive stress of approximately 1 GPa. A friction coefficient against Al 2O 3, ranging from 0.75 to 0.25 and a low surface roughness of approximately 1 nm were found to be accompanied by a refractive index ranging from 1.85 to 2.10 (at 550 nm) and an extinction coefficient between 1.0×10 −4 and 4.5×10 −2. The film behavior is correlated with the microstructure and composition determined by SEM, XPS, AFM and broad-range UV–VIS–NIR–IR spectroscopic ellipsometry.