Silicon particle detectors in the next generation of experiments at the CERN Large Hadron Collider will be exposed to a very challenging radiation environment. The principal obstacle to long-term operation arises from changes in detector doping concentration (Neff), which lead to an increase in required operating voltage. We have previously presented a model of inter-defect charge exchange between closely-spaced centres in the dense terminal clusters formed by hadron irradiation. This manifestly non-Shockley-Read-Hall mechanism leads to a marked increase in carrier generation rate and negative space charge over the SRH prediction. We present here measurements of spectra from 241Am alpha particles and 1064 nm laser pulses as a function of bias over a range of temperatures. Values of Neff and substrate type are extracted from the spectra and compared with the model. The model is implemented in both a commercial finite-element device simulator (ISE-TCAD) and a purpose-built simulation of inter-defect charge exchange. Deviations from the model are explored, and conclusions drawn as to the feasibility of operating silicon particle detectors at cryogenic temperatures.
Inter-defect charge exchange in silicon particle detectors at cryogenic temperatures
SANTOCCHIA, Attilio;PASSERI, Daniele;
2001
Abstract
Silicon particle detectors in the next generation of experiments at the CERN Large Hadron Collider will be exposed to a very challenging radiation environment. The principal obstacle to long-term operation arises from changes in detector doping concentration (Neff), which lead to an increase in required operating voltage. We have previously presented a model of inter-defect charge exchange between closely-spaced centres in the dense terminal clusters formed by hadron irradiation. This manifestly non-Shockley-Read-Hall mechanism leads to a marked increase in carrier generation rate and negative space charge over the SRH prediction. We present here measurements of spectra from 241Am alpha particles and 1064 nm laser pulses as a function of bias over a range of temperatures. Values of Neff and substrate type are extracted from the spectra and compared with the model. The model is implemented in both a commercial finite-element device simulator (ISE-TCAD) and a purpose-built simulation of inter-defect charge exchange. Deviations from the model are explored, and conclusions drawn as to the feasibility of operating silicon particle detectors at cryogenic temperatures.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.