Advanced Dopant Profile Control for Plasma Doping Processes

After intense research and development of plasma doping systems, successful application in low energy ion implantation has been demonstrated. Plasma doping enables new fabrication options for advanced CMOS and non-planar devices. Understanding plasma-surface interactions during plasma implantation is critical for successful development of new applications. During plasma immersion ion implantation, ionized species present in the plasma are extracted and implanted into the wafer, and, in addition, many other physical mechanisms, such as deposition, etching and sputtering, are competing in parallel. The dopant profile into the substrate results from contributions of all these mechanisms. By optimizing plasma composition and balancing deposition, etching and sputtering of the implanted surface, the dopant profile can be modified from typical surface peaked to retrograde/Gaussian profile. In this study, we report on the dopant profile optimization using ion mass spectrometry.