In this work, the wafer-scale silver nanoparticles fabricated by a self-assembly method was demonstrated based on a magnetron sputtering and plasma treatment process. Silver nanoparticles of different sizes and shapes were prepared, and the effects of the plasma treatment time, plasma gas composition, and power were systematically investigated to develop a method for low-cost and large-scale fabrication of silver nanoparticles. Furthermore, the surface-enhanced Raman scattering experiments: crystal violet, as the probe, was absorbed on the silver nanoparticles film of different size and density, and get the phenomena of surface-enhanced Raman scattering and surface-enhanced fluorescence. The results show that the proposed technique provides a rapid method for the fabrication of silver nanomaterial; the method is adaptable to large-scale production and is compatible with the fabrication of other materials and biosensors.