The silicon sensors for the Inner Tracker of the Compact Muon Solenoid experiment

The Inner Tracker of the Compact Muon Solenoid (CMS) experiment, at present under construction, will consist of more than 24 000 silicon strip sensors arranged in 10 central concentric layers and 2 � 9 discs at both ends. The total sensitive silicon area will be about 200 m 2 : The silicon sensors are produced in various thicknesses and geometries. Each sensor has 512 or 768 implanted strips which will allow the measurement of the position of traversing high-energy charged particles. This paper gives a short overview of the CMS tracker system. Subsequently, the design of the silicon sensors is explained with special emphasis on the radiation hardness and on the high-voltage stability of the sensors. Two companies share the production of these sensors. The quality of the sensors is extensively checked by several laboratories associated with CMS. Important electrical parameters are measured on the sensors themselves. In addition, dedicated test structures designed by CMS allow the monitoring of many parameters sensitive to the production process. By August 2003 about 5000 sensors were delivered and a large fraction of these sensors and test structures was measured.