Measurement of ion species ratio in the plasma source ion implantation process

Ion species and their ratios in nitrogen, oxygen, and argon plasmas in the plasma source ion implantation process have been determined with a simple and low-cost measurement system. The measured ion species ratio in the nitrogen plasma was used as an input parameter for the computer simulation code transport and mixing from ion irradiation to predict the atomic composition-depth profile. Comparison between the code results and data derived from Auger analysis for a nitrogen-implanted Ti-6Al-4V alloy showed good agreement. In this article, the design, performance, and possible future improvements regarding the resolution of this measurement system will be discussed.