Device simulation of irradiated silicon detectors at cryogenic temperatures

Radiation hardness is a critical design constraint for current and future generation silicon detectors, which are foreseen to undergo radiation fluences higher than 1×1014 cm−2 1-MeV neutron equivalent. Recently, low-temperature operating conditions have been suggested as an effective means to recover the negative effects of radiation damage on silicon detector collection properties. In order to investigate such an effect, simulations have been carried out using the ISE-TCAD DESSIS device simulator. The simulated results are compared with charge collection spectra obtained with 1064 nm laser pulses on devices irradiated with 23 GeV protons as a function of detector bias voltage. Thousands of simulation results have been cross-checked with the experimental data. The results obtained so far indicate that the “three-level model” can be successfully extended to predict irradiated detector behavior at least down to a temperature of 190 K.