Development of the fully-depleted thick back- illuminated CCD by Hamamatsu

We developed the fully-depleted thick back- illuminated CCD fabricated on N-type silicon wafer in collaboration with National Astronomical Observatory of Japan (NAOJ) for a next generation instrument for Subaru Telescope: a very wide-field CCD camera which named Hyper Suprime-Cam (HSC). The CCD format is 4-side buttable, 2 ktimes4 k 15 mum square pixels with 4 low noise output amplifiers. The optimization process was successfully completed. The recent evaluation results showed the charge transfer efficiency (>0.999995), the full-well capacity (>150 ke-), the charge conversion efficiency (5 muV/e-), the low dark(<5e-/pixel/hour at -100degC) and low noise (<5e- at 130 kHz readout, -100degC), high near-infrared QE (40% at lambda=1000 nm) and good surface flatness (15-20 mum). Owing to the new process factory of Hamamatsu, the CCD has the good cosmetics. These results are promising for HSC which requires more than 100 CCDs.