A novel method for effective sodium ion implantation into silicon

Although sodium ion implantation is useful to the surface modification of biomaterials and nano-electronic materials, it is a challenging to conduct effective sodium implantation by traditional implantation methods due to its high chemical reactivity. In this paper, we present a novel method by coupling a Na dispenser with plasma immersion ion implantation and radio frequency discharge. X-ray photoelectron spectroscopy (XPS) depth profiling reveals that sodium is effectively implanted into a silicon wafer using this apparatus. The Na 1s XPS spectra disclose Na2O–SiO2 bonds and the implantation effects are confirmed by tapping mode atomic force microscopy. Our setup provides a feasible way to conduct sodium ion implantation effectively.