206 / 2019-07-01 15:50:46

Influence of Roughness on Nondestructive Characterization of Interconnect Film Mechanical Properties by Surface Acoustic Wave

roughness,surface acoustic wave,finite element method

Surface acoustic wave (SAW) technology is a new nondestructive and fast on-line testing technology for mechanical properties of interconnect films. The theoretical dispersion curve of SAW propagating on the layered structure is obtained by the Green’s function and matrix method, assuming that the film surface and interface are smooth. In this paper, the random rough curves of the film surface and interface are obtained by the Monte Carlo method. The dispersion curves of the film/substrate structure considering the roughness are calculated by the finite element method. The dispersion curves obtained from ideal SAW model and roughness model are compared. The results indicate that the influence of surface and interface roughness on the determination of mechanical properties for SiO2 film and low-k film by the surface acoustic wave is small, and it can be ignored.