Modeling Neutron Damage in Silicon Detectors for High Energy Physics Experiments

Silicon detectors are expected to experience an unprecedented neutron flux in the future upgrades of the detectors at the Large Hadron Collider (LHC). The challenging radiation environment of these experiments will severely affect the performance of silicon detectors. An irradiation campaign is generally carried out, followed by measurements, to develop radiation-hard silicon detectors. Device modeling complements the measurement results for the detailed understanding of the silicon detectors. Our Group at the University of Delhi successfully developed the radiation damage model for proton irradiation. However, a similar model for neutron irradiation has been missing. In the present work, a Technology Computer-Aided Design (TCAD) simulation software—Silvaco, has been used to study the effects of neutron irradiation on silicon detectors. The effects of radiation damage are incorporated using an effective two-trap model. A trap level is characterized by a number of trap parameters, e.g. trap type, trap energy level, introduction rate of acceptors and donors, and carrier (electrons and holes) capture cross section for that particular trap level. A systematic study of the sensitivity of various macroscopic parameters of silicon detectors to these trap parameters has been performed. The simulation results on leakage current (ILEAK), full depletion voltage (VFD) and charge collection efficiency (CCE), using the neutron damage model, are found to be in good agreement with the measurement results