DIC Image on FIB Ring-Core Analysis of Depth Sensing Residual Stress Measurement of Thin Films

Abstract

This work demonstrates a technique to measure the residual stress of thin films that involves a combination of focused ion beam (FIB) milling, SEM imaging and digital image correlation (DIC) analysis. Use focused ion beam (FIB) to surface milling different depth of the ring core on thin film and capture the clear images with sub-micron resolution SEM. The residual stress measurement of 1.5 μm thick silver film through PVD Sputter and E-gun deposition was discussed. By the use of digital image correlation (DIC) for full-field strain analysis and calculate the displacement-strain relationship of the silver film surface and SEM high-resolution surface deformation images. The residual stress state of the two kinds of silver films was evaluated, which indicated that FIB-DIC was well implemented to measure the residual stress.