Study on Microstructure and Mechanical Properties of Silver and Silver-Indium Solid Solution Films Using Magnetron Sputtering

Pure silver and (Ag)-In solid solutions are recognized as vital materials for metal-to-metal solid-state bonding processes in the electronic packaging field, owing to their low yield strength and high plastic deformation capabilities. In this study, Ag and (Ag)-In solid solution films were obtained via magnetron sputtering under varying argon flow rates. The composition and phase characterization of the obtained Ag and (Ag)-In films were determined utilizing X-ray diffraction (XRD) techniques. The influence of different argon flow rates on the surface roughness of Ag and (Ag)-In films was analyzed using atomic force microscopy (AFM). Furthermore, the microstructure and grain orientation of the Ag and (Ag)-In films were examined via scanning electron microscopy/focused ion beam (SEM/FIB) methods, while the hardness of these films was assessed through nanoindentation analysis. The results show that increasing argon flow rate minimally impacts the orientation of pure Ag films, whereas the orientation in (Ag)-In films becomes more pronounced. Notably, the hardness of (Ag)-In films obtained under large argon flow rate is lower compared to pure Ag films, primarily due to differences in grain size and microstructure density. This investigation presents a novel material option for solid-state bonding applications within the realm of electronic packaging.