Fabrication, test and performance of very large X-ray CCDs designed for astrophysical applications

Abstract

A 6×6 cm 2 large X-ray CCD has been developed and fabricated at the Semiconductor Laboratory of the Max-Planck-Institut für Extraterrestrische Physik. The CCD has been designed for the focal plane cameras of two satellite missions. The concept is a fully depleted pn-CCD which is sensitive over the whole wafer thickness of about 300 μm. It has been especially developed for X-ray detection delivering a high quantum efficiency over the energy range between 0.2 and 15 keV. A production yield of 27% was achieved. Seven good (almost) defect-free wafers were produced within the performance requirements, i.e. for temperatures below 180 K they show a homogeneous noise level smaller than 5 e −, a uniform spectral response with an energy resolution of 130 eV for Mn-K α and a reduction of the sensitive area due to defects by less than 0.3%. Three CCDs have now been integrated in the flight cameras. The presentation comprises special aspects related with the fabrication of very large CCDs, a summary of the performance parameters and results of the qualification procedure of the European and German Space Agencies.