Relaxation of radiation damages in silicon planar detectors

The behaviour of radiation induced carbon related defects in high resistivity silicon detectors has been investigated. The defects were introduced by alpha-particle irradiation and the measurements were carried out by the DLTS-technique. The unusual defect behaviour consists in low temperature anealing, including self annealing at room temperature, of the interstitial carbon C_i with a simultaneous increase of the (C_i-O_i)-complex concentration. The kinetic parameters of the process have been determined from the increase of the C_i-centre concentration versus time. Tho annealing velocities have been observed, which ar due to different heat treatments during the detector fabrication process.