Evaluation of interfacial adhesion between Si substrate and organic polymer dielectric film

Recently, organic polymer dielectric films attract attention as promising dielectric films that reduce environmental burdens and inhibit RC-delays. However, its mechanical properties have not been investigated. Therefore, we evaluated its reliability by measuring the interfacial energy release rates during the delamination under various conditions. In this study, SiLK (trademark of the Dow Chemical Company) is selected as dielectric material. We prepared two types of specimens. One consists of spin-coated SiLK layer sandwiched between Si substrates using adhesion bond. The other is made by the following process; solution of SiLK is sandwiched between Si substrates, and it is cured by heating. Four point bending tests and double cantilever beam tests were performed. In the meantime, delamination paths were identified using SEM and ESCA. In the case of heat curing specimens, delamination propagated along interface between Si/SiLK, so we were able to estimate the interfacial energy release rates. By the results of tests under different mode mixties, we could evaluate the criterion for fracture using elipse approximation.