Simultaneous determination of the Young's modulus and Poisson's ratio in micro/nano materials

Most mechanical properties of micro/nano materials cannot be determined using purely theoretical approaches or by extrapolation from bulk measurements. These properties are usually extracted experimentally by using micromechanical test structures such as cantilevers. This paper reports a novel cross-shaped structure used to simultaneously extract the Young's modulus and Poisson's ratio using the force-deflection principle. Equations for calculating the Young's modulus and Poisson's ratio are derived, and using these, an experimental demonstration of this method is presented. The average values of the Young's modulus and Poisson's ratio for the device layer commercially sourced silicon on a silicon-on-insulator (SOI) wafer are measured to be 116.5 +/- 2.24 GPa and 0.32 +/- 0.03, respectively.