Microbridge testing of Young's modulus and residual stress of nickel film electroplated on silicon wafer

Microbridge testing is used to measure the Young's modulus and residual stresses of metallic films. Nickel film microbridges with widths of several hundred microns are fabricated by microelectromechanical systems. In order to measure the mechanical properties of nickel film microbridges, special shaft structure is designed to solve the problem of getting the load-deflection curves of metal film microbridge by nanoindenter XP system with normal Berkovich probe. Theoretical analysis of the microbridge load-deflection curve is proposed to evaluate the Young's modulus and residual stress of the films simultaneously. The calculated results based on the experimental measurements show that the average Young's modulus and residual stress are around 190 GPa and 175 MPa respectively, while the Young's modulus measured by nanohardness method on nickel film with silicon substrate is 186.8±7.34 GPa.