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/cm2, 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.
Highlights
Silicon sensors, widely used in high energy and nuclear physics experiments, suffer severe radiation damage that leads to degradations in sensor performance
Increase of sensor leakage current under radiation is caused by the radiation induced deep level defects that act as generation and recombination centers
2.4 Space charge transformations and CCE loss 2.4.1 Space charge transformation in as-irradiated Si sensors For a fully depleted n-type Si sensor under radiation, the space charge sign undergoes a transformation from initially positive, to negative, termed as the space charge sign inversion (SCSI). This SCSI is caused by two processes: the donor removal (DR) and acceptor creation (AC)
Summary
It is well known that neutrons, protons, electrons, and even gamma radiation can lead to displacement damage in Si. The displacement damage is caused by displacement of a Si atom from its substitution site to an interstitial site to form a Frenkel pair, as shown in figure 1 for neutron situation. In the case of neutron radiation, due to the high Si recoil energy (133 keV), the displacement damage is a cascade with many interactions, resulting in an extended damage region, or defect clusters [8]. In the case of gamma radiation, the displacement damage is caused by the Compton electrons (about 1 MeV in energy) that only produce isolated single defects when vacancies/interstitials react to each other or to impurities in the Si, as shown in figure 1.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
