Experience with silicon sensor performance and quality control for a large-area detector

The CMS silicon tracker, at present under construction, will consist of 10 barrel layers and 2×9 end cap discs inside a volume of about 5.6 m length and 2.4 m radius. The total sensitive area covered by silicon will exceed 200 m2. To cope with the expected radiation damage induced by the particle fluence at the Large Hadron Collider the detector will be operated at −10°C. Two companies manufacture the 25 000 silicon sensors in 15 different geometries. The delivery of the sensors is under way and hence an extensive quality control program for the sensors has been put in operation. The paper gives an overview of the CMS tracker system and subsequently concentrates on the results from the sensor tests. In addition, measurements on dedicated test structures are presented which were designed to monitor the stability of the sensor production process.