Radiation hardness of oxygenated microstrip detectors read out with LHC speed electronics

Abstract

Full-size and miniature Large Hadron Collider (LHC) detectors fabricated on 4-and 6-in wafers have been processed using oxygenated and nonoxygenated substrates. After irradiation to 3 10 14 cm 2 with 24-GeV/c protons and short-term annealing, these detectors have been studied in terms of their charge collection as a function of depletion voltage with LHC-speed analog electronics. Results are presented indicating the degree of improvement seen in terms of the main operationally significant parameter, namely, the bias voltage needed for a given signal read out with fast electronics.

Radiation damage in silicon detectors for high-energy physics experiments

“…The beneficial effect of oxygen in -irradiated Si detectors was observed by C-V measurements: oxygen-enriched detectors showed very little change in up to 600 MRad and do not exhibit inversion indicated by a change in the sign of , while detectors made with standard FZ Si show inversion at about 250 MRad. Charge-collection efficiency measurements have been performed on oxygenated microstrip and single pad detectors [79]. ATLAS microstrip detectors with -strip readout made from oxygen-enriched FZ Si ([O ] cm ) have been irradiated with 24-GeV/c protons up to 3 10 cm .…”

“…The benefit of using the oxygen-enriched material is less pronounced for microstrip detectors located in the barrel layer at cm, as in this latter case charged hadrons contributes only by 50% to the total equivalent fluence, while the remainder is also given by albedo neutrons. Unfortunately, the lower observed by C-V measurements in proton-irradiated oxygenated materials does not correspond to a lower value of the bias needed to maximize the CCE [79]. More studies are therefore needed on oxygenated silicon microstrip detectors before undertaking the decision to use DOFZ on a large scale in ATLAS and CMS microstrip and pixel detectors.…”