Study of noise and spectroscopic performance of DEPMOSFET matrix prototypes for XEUS

The current generation of DEPMOSFET-based Active Pixel Sensor (APS) matrix devices has been developed to cope with the challenging requirements of the XEUS Wide Field Imager. The devices turned out to be a promising new imager concept for a variety of X-ray imaging applications. The devices combine excellent energy resolution, high-speed readout and low power consumption with the attractive feature of random accessibility of pixels. Sensor prototypes, built for row-wise readout, with 64 × 64 pixels with a size of 75 × 75 μ m 2 each have been produced at the MPI semiconductor laboratory in Munich, and their performance has been studied in detail. A spectroscopic resolution of 128 eV has been measured, the readout noise is as low as 3.5 e - ENC. Here, measurements of the dependence of readout noise and spectroscopic resolution on the device temperature are presented.