Residual Stress Evaluation of Thin Film Using Strip Bending Test

In this study, we use the strip-bending test to measure the residual stress of a thin film structure. The principle of the strip bending test and the test procedures are described and the analysis of the strip deformation is presented. The explicit formula for estimating the residual stress is given, which requires the initial stress as an input. As an example, the E-beam evaporated Au thin film is chosen, and the residual stress is measured by the present method. The Au thin film structure has a tensile or compressive residual stress depending on the film thickness. The tensile and the compressive residual stresses of Au thin film are successfully measured by the present method.