Tunability unraveled for elastic properties of cubic silicon carbide thin film compound semiconductor

Abstract

Elastic properties, Young's modulus, and Poisson's ratio become highly tunable with the change from bulk material to thin films, presenting distinct advantages for micro- and nanofabrication. Here, we demonstrate the tunability of Young's modulus and Poisson's ratio in cubic silicon carbide (3C–SiC), a prominent compound semiconductor epitaxially grown on silicon (Si). By precisely controlling the carbon-to-silicon atomic ratio (C/Si) during growth, we achieve a wide range of elastic property values that overlay vastly scattered values reported in literature. Observed variations in lattice strain are attributed to the incorporation of substitutional carbon atoms. Importantly, elastic properties of our thin films are derived independently of bulk material assumptions, providing standalone reference values. Young's modulus and Poisson's ratio for stoichiometric 3C–SiC(001) epilayers were derived as 309 ± 8 GPa and 0.21 ± 0.02, respectively. This approach enhances our understanding of thin film mechanics and offers a pathway to tailor elastic properties in other heteroepitaxial compound semiconductor systems for advanced applications.