Radiation damage effects in Si materials and detectors and rad-hard Si detectors for SLHC

Abstract

Silicon sensors, widely used in high energy and nuclear physics experiments, suffer severe radiation damage that leads to degradations in sensor performance. These degradations include significant increases in leakage current, bulk resistivity, space charge concentration, and free carrier trapping. For LHC applications, where the total fluence is in the order of 1 × 1015 neq/cm2 for 10 years, the increase in space charge concentration has been the main problem since it can significantly increase the sensor full depletion voltage, causing either breakdown if operated at high biases or charge collection loss if operated at lower biases than full depletion. For LHC Upgrade, or the SLHC, however, whit an increased total fluence up to 1 × 1016 neq/cm 2, the main limiting factor for Si detector operation is the severe trapping of free carriers by radiation-induced defect levels. Several new approaches have been developed to make Si detector more radiation hard/tolerant to such ultra-high radiation, including 3D Si detectors, Current-Injected-Diodes (CID) detectors, and Elevated temperature annealing. © 2009 IOP Publishing Ltd and SISSA.