Examination of Bulge Test for Determining Residual Stress, Young’s Modulus, and Poisson’s Ratio of 3C-SiC Thin Films

Despite great advancements in thin-film growth and deposition techniques, determination of the residual stress and Young’s modulus for thin films has continued to be a challenge. The bulge test is a potentially powerful tool for characterizing these mechanical properties but is underutilized because of its sensitivity to experimental error. The bulge test is highly sensitive to sample and test preparation, accuracy of the deflection measurement, accuracy in the measurement of film dimensions, and selection of the correct equation to be used for extraction of the Young’s modulus and residual stress. In this study, effort has been made to consolidate the findings from various reports in the literature, and a thorough error analysis has been conducted. A discussion on the experimental technique used to extract Poisson’s ratio from the bulge test is also presented. Finally, the technique is used to determine the residual stress and Young’s modulus of 3C-SiC thin films grown on silicon.