Fabrication of smooth SAC305 thin film via magnetron sputtering

Abstract

SAC305 (96.5 wt% Sn, 3 wt% Ag, 0.5 wt%Cu) solder is increasingly becoming popular due to its reliability good characteristics and performance in addition to the environmental concerns and regulations that restrict the use of lead in nano/microelectronic products. In nano/microelectronics, manufacturing smooth solder coatings free of defects such as voids and cracks, which can compromise joint reliability is crucial. Magnetron sputtering offers a high degree of control over film thickness and composition, resulting in films with excellent uniformity and adhesion. Despite these advantages, fabricating continuous and robust SAC305 films using magnetron sputtering remains a difficult task with limited research addressing these Challenges. To address these challenges and obtain an enhanced surface morphology property, we focus on fabricating SAC305 thin films by optimizing the magnetron sputtering parameters including sputtering power and pressure, and by using various substrates. Field emission-scanning electron microscopy imaging, energy-dispersive X-ray spectroscopy, X-ray diffraction, and atomic force microscopy were used to evaluate the quality of the thin films.