Radiation damage in silicon detectors

In this work effects of radiation damage to the properties of Si-nuclear radiation detectors are investigated. Theoretical and experimental investigations were made concerning the influence especially of α-particles (5.5 MeV) and electrons (E/sub max/ = 2.27 MeV) to essential detector parameters, like minority carrier lifetime, energy resolution and counting efficiency of ion-implanted detectors from high resisitivity FZ- and NTD-Si. The medium damage constants are: K/sub tau/ (α) = 3.5 x 10-6 cm2/s, K/sub tau/ (β) = 5 x 10-9 cm2/s. If the oxide passivation layer is irradiated too the damage constants increase of one are two orders of magnitude. The decrease of lifetime at high does leads to a increasing of reverse current and electronic noise. The energy resolution for α-spectrometric measurements at doses of PHI/sub α/ >= 5 x 1010 cm-2 and PHI/sub e/ >= 5 x 1013 cm-2 respectively is determined by charge carrier loss on radiation induced defects. The maximum possible irradiation dose for spectrometric detectors amounts 2...5 x 1010 cm-2 for α-particles and 5...50 x 1012 cm-2 for electrons. For counting detectors these values increase of one or two orders of magnitude. For radiation damaged detectors a partial or even a complete defect annealing is possible. (author)