Si3N4 Young’s modulus measurement from microcantilever beams using a calibrated stylus profiler

Abstract

Stylus surface profiler has been widely used in order to measure Young’s modulus of silicon nitride (Si₃N₄) from microcantilever beams. Until now, several Si₃N₄ Young’s modulus values have been reported. It may be due to incomplete assessment of the microcantilever beams bending over its entire length or a lack of calibration of the stylus force system used in those works. We presented in this work an alternative method to measure the elastic modulus of MEMS thin layers in a rather accurate manner. A stylus force calibration is reported from a calibrated silicon microcantilever beam in order to measure the Si₃N₄ Young’s modulus. We reported Si₃N₄ Young´s modulus from three microcantilever beams, with values of 219.4 ± 0.6 GPa, 230.1 ± 3.4 GPa and 222 ± 11 GPa for 50 µm, 100 µm and 200 µm wide respectively, which are in good agreement with respect to the Si₃N₄ Young´s modulus which have been determined by other methods.