This paper describes the AC-coupled, single-sided, p-in-n silicon microstrip sensors used in the SemiConductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The sensor requirements, specifications and designs are discussed, together with the qualification and quality assurance procedures adopted for their production. The measured sensor performance is presented, both initially and after irradiation to the fluence anticipated after 10 years of LHC operation. The sensors are now successfully assembled within the detecting modules of the SCT, and the SCT tracker is completed and integrated within the ATLAS Inner Detector. Hamamatsu Photonics Ltd supplied 92.2% of the 15,392 installed sensors, with the remainder supplied by CiS.

Nonirradiated and irradiated ATLAS silicon microstrip barrel and endcap modules have been beamtested with 4-GeV/c pions. Pulse shapes confirmed the peaking time of the amplifier to be 22 ns with slight deterioration in the irradiated modules. Median charges saturated around 3.8 fC, both in the nonirradiated and the irradiated modules. Signal/noise ratios, using the noise estimates from the in-situ calibration, were 16 in the nonirradiated ( 150 V) and 10 in the irradiated ( 300 V) barrel modules. No excess common-mode noise was observed.Index Terms-Radiation damage effects, silicon microstrip radiation detectors.