Silicon nitride thin films Young's modulus determination by an optical non destructive method

The purpose of our study is to determine the Young's modulus of silicon nitride (Si3N4) thin films. With respect to the experimental material, we use commercially available atomic force microscopy (AFM) microcantilevers. The novelty lies in the procedure used to compare and therefore to validate the experimental results. First, the fundamental mode of Si3N4 thin film microcantilevers is detected by means of the optical beam deflection (OBD) method. The resulting resonant frequency is subsequently introduced into the mechanical theoretical model to extract the value of the Young's modulus. A numerical modal analysis is performed to validate the experimental results using the same approach as that of the experiment. Finally, the Young's modulus obtained in this study is compared with those of other studies. The outcome shows that we have obtained a, reliable protocol for Young's modulus estimation.