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.
For chemically amplified EUV resists, secondary electrons derived from ionization events play a critical role
in the sensitization of acid generators. In this study, we show the dependence of acid generation efficiency on
dose rate (fluence per pulse duration) by using 61 nm free-electron laser (FEL) light irradiation. The
wavelength of 61 nm (20.3 eV) is applied because single incident photon induces only single ionization event,
in contrast to the 13.4 nm EUV photon that induces 4.2 ionization events on average. The acid yield
efficiency has enhances with decreasing the dose rate. It is suggested that high density ionization enhances the
multiple spur effect.