Quantitative Evaluation of the Nano-Scaled Polymeric Film System

In recent years, a nano-scaled thin film often applied to the industries (e.g., MEMS/NEMS device, semiconductor, display, optical coating or the like). Generally the materials used to the nano-scaled thin film systems have different mechanical properties comparing to the conventional bulk materials. Therefore, it is important to measure the mechanical properties for the nano-scaled thin film. Especially the properties of the pre-treated surface of the substrate effect to the reliability of the adhesive strength between the film and the substrate. In this study we controlled the surface treatment processes to obtain the different adhesive conditions at the interfaces of the systems. Then, we applied acoustic spectroscopy (i.e., V(z) curve technique) to evaluate adhesive strength of the interface. Further, nano-scratch test was applied to the systems to obtain the co-relations between the SAW velocity and the adhesive strength, and the co-relation between the SAW velocity and hardness, respectively. Experiments on the system with different adhesive conditions showed that SAW velocity was sensitive enough to evaluate the film interface conditions. Consequently, the obtained preliminary data showed potentials for nondestructively characterizing the adhesive conditions at the interface of the nano-scaled thin film system with acoustic microscopy.