Radiation-hard strip detectors on oxygenated silicon

Recent results of the RD48 (ROSE) collaboration suggest the usage of oxygen-enriched silicon for sensors operated in the harsh radiation environment of future high luminosity experiments. To investigate if the anticipated beneficial properties are still present after full processing of the wafers, full-size strip detectors designed for the innermost ring of the ATLAS forward region have been fabricated on oxygen-enriched silicon by CiS, Germany. These sensors, together with sensors processed in exactly the same way on standard substrates of different thickness, have been exposed to 3×10¹⁴ 24 GeV/c protons/cm² at the CERN PS. After irradiation, the sensors went through a controlled annealing up to an equivalent annealing time of 32 d at 25°C. We are presenting the comparison between these sensors based on I-V and C-V measurements and the investigation of the charge-collection efficiency obtained with a ⁹⁰Sr source and fast analog readout at Large Hadron Collider speed.