Characterization of Prototype BTeV Silicon Pixel Sensors Before and After Irradiation

We report on measurements performed on silicon pixel sensor prototypes exposed to a 200 MeV proton beam at the Indiana University Cyclotron Facility. The sensors are of n + /n/p + type with multi-guard ring structures and p-stop electrode isolation on the n +-side. Electrical characterization of the devices was performed before and after irradiation up to a proton fluence of 4 × 10 14 p/cm 2. We tested pixel sensors fabricated from normal and oxygen-enriched silicon wafers and with two different p-stop isolation layouts: common p-stop and individual p-stop.