Mechanical and Interfacial Properties Characterization of Physical Vapor Deposited Metallic Films after Rapid Thermal Annealing for Packaging Applications

This work presents the residual stress, elastic modulus, and interfacial strength characterizations of aluminum films deposited on silicon wafers after rapid thermal processing as the first step toward the reliability assessment of metallic/dielectric heterogeneous structures, which have been widely used in integrated circuits and packaging applications, for improving structural integrities. Various techniques such as curvature measurement, nano-indentation, and scratching test have been hired to conduct the investigation. It is found that the residual stress, modulus and hardness, as well as the adhesion would strongly depend on thermal processing temperature, deposition rate, and deposition thickness. In conjunction with subsequent finite element stress analysis, the obtained data would then be used as the core for improving structural design in IC and packaging structures and processing.