A comparative study of radiation damage on high resistivity silicon

In future particle accelerators, silicon detectors will be exposed with lar ge doses of different types of radiation. To understand the corresponding p roduced damage mechanisms, a systematic study of the influence of the irrad iation on the silicon from which the detectors are made has to be carried o ut. Samples of low n-doped silicon (n less than or equal to 10(12) cm(-3)) have been irradiated with swift krypton ions ((E) = 5.2 GeV), neutrons from a nuclear reactor ((E) similar to 1 MeV) and energetic electrons ((E) = 1. 5 MeV). Resistivity and Hall effect measurements performed after irradiatio n show that the silicon is changed to a quasi-intrinsic state, characterize d by a very high resistivity. The electrically active defects responsible f or that evolution are mainly acceptor centers, namely divacancy and/or vaca ncy-doping complexes. Besides, for the highest fluences, only the appearanc e of a donor center located at about 0.59 eV below the conduction band may explain the observed stabilization of the Fermi level at 0.61 eV. Finally, using a simulation method, the rates of generation of the different defects are estimated.