Young’s Modulus Measurement for Polysilicon Thin Film by Tensile Testing

Abstract

Young’s modulus of polysilicon thin film was measured by means of a tensile tester equipped with electrostatic force grip system. The images of gauge marks on a specimen were captured by a high-speed digital CCD camera and the tensile strain was calculated from the images. Polysilicon thin film specimens were tensile tested for evaluating the resolution of the measurement system. The polysilicon specimens were 1.7 µm thick, 20 and 50 µm wide, and 100 and 500 µm in gauge length. The linear stress-strain curve was obtained and Young’s modulus was measured. The mean Young’s modulus ranged from 162 to 175 GPa, which agreed with the theoretical value and the measured values using the bulge method. The resolution and the comparison to the differential method were discussed.