A direct-detection X-ray CMOS image sensor with 500 μm thick high resistivity silicon

This paper reports recent results of a direct-detection X-ray CMOS image sensor for X-ray Free-Electron Laser (XFEL) experiments. The sensor incorporates the in-pixel dual gain circuitry by using Fully Depleted-Silicon-On-Insulator (FD-SOI) CMOS transistors located on top of the buried oxide (BOX) layer. Beneath of the BOX layer, high resistivity handle wafer made from floating zone method was formed as p-n junction diode to detect X-rays. Between the handle wafer and the FD-SOI CMOS, via through BOX layer is formed to transfer the charge. This paper describes the production method and sensor architecture of the sensor. In addition to the scientific demands of XFEL experiments, a general X-ray imaging application by using this sensor architecture is also presented.