Unveiling the multifaceted impact of C2H2 flow on SiCN CVD coatings: Mechanical mastery and beyond

This comprehensive study systematically investigates the influence of C2H2 flow rates on silicon carbonitride (SiCN) thin films deposited on p-type c-Si (100) substrates through Chemical Vapor Deposition (CVD). Across a range of C2H2 flow rates (1–15 sccm), the study quantitatively analyzes surface morphology, crystallinity and mechanical characteristics. Analyzing the data quantitatively: SEM and AFM analyses unveiled distinctive surface patterns influenced by varying C2H2 flow rates. Surface roughness exhibited a quantitative increase, rising from 1.2 nm at 1 sccm to 2.4 nm at 15 sccm. FTIR spectroscopy identified three major vibrational signatures in SiCN thin films: Si-Hn wagging, n-SiC, and Si–C stretching. Notably, the intensity of the n-SiC peak demonstrated a quantitative rise with increasing C2H2 flow rate. XRD confirmed the quantitative impact of C2H2 flow rates on crystallinity. The SiCN thin film deposited at 15 sccm exhibited the highest crystallinity, with a quantified crystallite size of 15 nm. Hardness and Young's modulus were quantitatively assessed through nanoindentation testing. SiCN thin films showed a quantitative increase in both hardness and Young's modulus with rising C2H2 flow rates. The film deposited at 15 sccm demonstrated the highest hardness (i.e. 19.23 GPa) and Young's modulus (i.e. 271.56 GPa). In summary, this study establishes the significant impact of C2H2 flow rates on the quantitative aspects of surface morphology, crystallinity, and mechanical properties of SiCN thin films. Notably, the film deposited at 15 sccm emerges as distinctive, exhibiting the highest quantitative values for crystallinity, hardness and Young's modulus. This comprehensive analysis enhances the understanding of intricate relationship between C2H2 flow rates and the multifaceted properties of SiCN thin films.