Back-illuminated CCDs developed for the reflection grating spectrometer onboard of XMM

Back-illuminated CCDs with high quantum efficiency in the soft X-ray range have been developed by EEV in collaboration with the Space Research Organisation of the Netherlands (SRON) and the European Space Agency (ESA). These CCDs will be used as detector for the Reflection Grating Spectrometer onboard of the ESA X-ray Multi-Mirror Mission XMM. To cover the full image of the reflection grating spectrometer an array of 9 CCDs along the Rowland circle with minimum dead space between the adjacent CCDs is needed. To obtain a high quantum efficiency over the full energy range (0.35 to 2.3 keV) the CCDs are illuminated from the backside. This requires a thin (similar to 50 nm) and homogeneous passivated layer at the backside, which is obtained by Gas Immersion Laser Doping. In addition a thin Al layer is deposited on the backside to reduce the sensitivity of the CCDs for visible/UV light.