Observation of size effect and measurement of mechanical properties of Ti thin film by bulge test

In this study, the mechanical properties of a Ti thin film are measured by a bulge test. In the bulge test, uniform pressure is applied to one side of the film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties of the film. Ti thin films with thicknesses of 1.0, 1.5, and 2.0μm were deposited on a Si wafer by using an RF magnetron sputtering system. These specimens were annealed at 600 .deg. C for 150, 300, and 600s to investigate the effect of temperature on the yield stress and mechanical properties of the Ti films. The elastic modulus, residual stress, and yield stress of these membranes are measured by a bulge test. The experimental results suggest that the yield stress is sensitive to the film thickness and annealing time