Estimation of elasticity modulus and fracture strength of thin perforated SiN membranes with finite element simulations

Effective design of microsieves based on thin plates requires the estimation of the load capacity being equal to the critical (bursting) pressure, that causes the rupture of the plate. Elasticity modulus and fracture strength strongly affect this pressure of perforated and porous thin membranes to be used widely for microsieving purposes. Since these material parameters depend heavily on the method of silicon-nitride (SiN) deposition, measurements are required to determine them in case of each application. With the help of finite element simulations closed form analytical estimates are derived to predict elasticity modulus and fracture strength using the measured or calculated deflection and verified stress in the middle point of the square-form membrane. The method developed also serves to find improved relationship between the above material parameters of closed and perforated membranes.