Are particulates sabotaging your thin films? This study investigates the mechanisms behind particle contamination during magnetron sputtering, a process crucial for thin film fabrication. Using laser light scattering, researchers monitored particles greater than 0.3 μm on the target, substrate, and in the plasma, revealing distinct mechanisms for particle generation, transport, and trapping compared to plasma etch processes. One key source of particle contamination is linked to target surface areas with weaker plasma density, where film redeposition promotes filament or nodule growth. Sputter removal of these features is inhibited by sputter yield dependence on incidence angle, leading to plasma particle trapping and increased filament growth. These growths can short-circuit the sheath, causing mechanical failure, fracture, and ejection of target contaminants. Observed in both semiconductor fabrication and storage disk manufacturing, this mechanism may be universal to many sputter processes. These insights pave the way for strategies to minimize particle contamination and improve the quality of thin films in various applications.
Published in the Journal of Vacuum Science & Technology A, this article aligns with the journal's scope on vacuum processes and thin film deposition. The research offers insight into particle formation mechanisms during magnetron sputtering. The paper enriches the journal’s content in plasma physics and materials science.