This work focuses on the investigation of radiation induced defectsresponsible for the degradation of silicon detectors. Comparative studies ofthe defects induced by irradiation with 60Co- rays, 6 and 15 MeV electrons, 23GeV protons and 1 MeV equivalent reactor neutrons revealed the existence ofpoint defects and cluster related centers having a strong impact on damageproperties of Si diodes. The detailed relation between the microscopic reasonsas based on defect analysis and their macroscopic consequences for detectorperformance are presented. In particular, it is shown that the changes in theSi device properties after exposure to high levels of 60Co- doses can becompletely understood by the formation of two point defects, both dependingstrongly on the Oxygen concentration in the silicon bulk. Specific for hadronirradiation are the annealing effects which decrease resp. increase theoriginally observed damage effects as seen by the changes of the depletionvoltage. A group of three cluster related defects, revealed as deep hole traps,proved to be responsible specifically for the reverse annealing. Theirformation is not affected by the Oxygen content or Si growth proceduresuggesting that they are complexes of multi-vacancies located inside extendeddisordered regions.
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