Development and performance of Kyoto's x-ray astronomical SOI pixel (SOIPIX) sensor

We have been developing monolithic active pixel sensors, known as Kyoto’s X-ray SOIPIXs, based on the CMOS SOI (silicon-on-insulator) technology for next-generation X-ray astronomy satellites. The event trigger output function implemented in each pixel offers microsecond time resolution and enables reduction of the non-X-ray background that dominates the high X-ray energy band above 5–10 keV. A fully depleted SOI with a thick depletion layer and back illumination offers wide band coverage of 0.3–40 keV. Here, we report recent progress in the X-ray SOIPIX development. In this study, we achieved an energy resolution of 300 eV (FWHM) at 6 keV and a read-out noise of 33 e- (rms) in the frame readout mode, which allows us to clearly resolve Mn-Kα and Kβ. Moreover, we produced a fully depleted layer with a thickness of 500 μm. The event-driven readout mode has already been successfully demonstrated.