Measurements of Interface Fracture and Mechanical Properties of Low-K Dielectric Thin Films

Abstract

The residual stresses and the biaxial elastic modulus of low-k dielectric thin films, and in particular the interfacial fracture energy of these films on a silicon substrate were all measured using a single method. The method consists of depositing a thin metallic ‘super layer’ on top of cantilever beam structures [1] of the low-k dielectric thin films, manufactured using the conventional micro machining processes. The ‘super layer’ generates tensile stresses in the investigated thin layers. When these beams are either released from the substrate or separated by spontaneous crack propagation initiated from a natural precrack, a curvature of the bilayer beam structures is formed and used to evaluate the above properties of the thin films and of the interface.