Fracture properties of PECVD silicon nitride thin films by long rectangular memrane bulge test

Bulge test combined with a refined load-deflection model for long rectangular membrane was applied to determine the mechanical and fracture properties of PECVD silicon nitride (SiN_x) thin films. Plane-strain modulus E_ps, prestress s₀, and fracture strength s_max of SiN_x thin films deposited both on bare Si substrate and on SiO₂-topped Si substrate were extracted. The SiN_x thin films on different substrates possess similar values of E_ps and s₀, but quite different values of s_max. The statistical analysis of fracture strengths were performed by Weibull distribution function and the fracture origins were further predicted.