Plasma potential measurement on ECRIS by using extracted ion beam

With the miniaturization of semiconductors, the technology of shallow junctions becomes important. As shallow junctions advance, ion implantation by using ion beams at low energy with good control is needed. An electron cyclotron resonance ion source (ECRIS) can efficiently generate a high-density plasma at low pressure and a high intensity ion beam. In our ECRIS, the wide operation of various ion beam is available from deeper implantation of multi-charged ions at high energy to shallow junction at very low energy. However, a potential and a sheath near the wall are formed with an ECR plasma, because ECRIS is a volume source. Therefore, the potential affects the control of the ion beam at very low energy. In this study, we measure the potential by using the ion beam extracted from the ECRIS. In addition, we confirm that the potential by using the ion beam method correlates with electron temperature when microwave power and pressure change in ECRIS.