Mechanical properties of epitaxial 3C silicon carbide thin films

Abstract

Microscale tensile specimens of epitaxial 3C silicon carbide (3C-SiC) thin films were fabricated on Si substrates and tested to provide measurements of strength and elastic modulus. Samples were fabricated using both micromolding and reactive ion etching (RIE) processes to pattern the 3C-SiC films. All specimens were on the (100) plane with a <110> tensile direction. Testing was performed on a microsample tensile testing machine previously used on other materials. The samples had a thickness of 0.5 to 2 /spl mu/m, a gauge length of 4 mm, and a minimum width of 600 /spl mu/m. Testing results show an average strength of 1.19 /spl plusmn/ 0.53 GPa and 1.65 /spl plusmn/ 0.39 GPa for micromolded and RIE patterned specimens, respectively. The elastic modulus was measured to be 424 /spl plusmn/ 44 GPa, which was consistent with but slightly lower than the elastic modulus calculated with single crystal elastic constants found by ab initio calculations.