Energy enhancement on NV-GSD-HE

Higher energy boron implantation has been being required for CCD application on the NV-GSD-HE (HE). The HE LINAC acceleration system has characteristics that acceleration efficiency is dependent on a mass-to-charge ratio of ions to be accelerated. The maximum energy of boron is 2.3 MeV while that of phosphorus is 3.0 MeV since the original HE was designed to maximize the acceleration efficiency for singly charged phosphorus, while that for multiply charged boron is relatively poorer. New configuration of RF acceleration on the HE has been developed in order to increase the maximum energy of boron. On this configuration newly designed RF electrodes and electrostatic quadrupole lenses optimized for small mass-to-charge ratio ions are introduced, replacing the original electrodes and quadrupole lenses. As a result, the maximum energy of triply charged boron is increased up to 2.94 MeV and the maximum energy of doubly charged phosphorus is 2.6 MeV. Therefore, the newly configured tool can be used both for the CCD application and the well formation, including the triple well