The measurement of nitrogen ion species ratio in inductively coupled plasma source ion implantation

The internal inductively coupled nitrogen plasma was studied to find optimum conditions of ion species ratio in plasma source ion implantation processes. The ratio of nitrogen ion species, i.e. N2+ and N+, was measured with quadrupole mass analyzer (QMA) and a single Langmuir probe. The results of QMA and a single Langmuir probe measurement showed very good agreement and it was shown that a single Langmuir probe could be used to measure the ion species ratio easily. For the confirmation of the measured ion species ratio, nitrogen ions were implanted into Si wafer and scanning Auger analysis was performed to investigate the depth distribution of implanted nitrogen ions.