Design and test of pixel sensors for the CMS experiment

The Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) will have a silicon pixel detector as its innermost tracking device. The pixel system will be exposed to the harsh radiation environment of the LHC. Prototype sensors have been designed to meet the specifications of the CMS experiment. The sensors are n+–n devices to allow partial depletion operation after bulk type inversion. The isolation of the n+ pixels is provided through a novel double open p-ring design that allows sensors testing before bump bonding and flip chipping. The prototype wafers contain a variety of p-stop designs and are fabricated by two vendors on different bulk substrates including oxygenated silicon. A study of the static measurement of the prototype sensors before irradiation is presented.