Effect of irradiation and annealing performed with bias voltage applied across the coupling capacitors on the interstrip resistance of ATLAS ITk silicon strip sensors

Abstract

The powering configuration of the silicon strip modules developed for the new Inner Tracker of the ATLAS experiment includes a voltage of up to 0.5 V across the coupling capacitor of each individual strip. However, this voltage is usually not applied in the sensor irradiation studies due to the significant technical and logistical complications. To study the effect of an irradiation and a subsequent beneficial annealing on the strip sensors in real experimental conditions, four prototype ATLAS17LS miniature sensors were irradiated by 60Co source and annealed, both with and without the bias voltage of 0.5 V applied across the coupling capacitors. The values of interstrip resistance measured on irradiated samples before and after annealing indicate that increase of radiation damage caused by the applied voltage can be compensated by the presence of this voltage during annealing.