A deep level transient spectroscopy study of electrically active defects in electron irradiated Si detectors was performed. Two types of materials were studied and compared: C-lean magnetic Czochralski (MCZ-) Si, and high purity, diffusion oxygenated float-zone (DOFZ-) Si. In both materials, an earlier reported shift in the position of peaks associated with the divacancy (V2) at 250–325C was observed, indicating a gradual transition from V2 to the divacancy–O complex (V2O). Heat treatments at higher temperatures revealed a difference in annealing behavior of defects in DOFZ- and MCZ-Si. It was observed that VO and V2O annealed with a higher rate in DOFZ-Si. The appearance of a H related level only in the DOFZ-Si revealed a small presence of H and it was suggested that the difference in annealing behavior was due to defect interaction with H in the DOFZ-Si. The findings also suggested that dissociation may be a main mechanism for the annealing of V2O in MCZ-Si.

Annealing of Defects in Irradiated Silicon Detector Materials with High Oxygen Content. M.Mikelsen, E.V.Monakhov, G.Alfieri, B.S.Avset, J.Härkönen, B.G.Svensson: Journal of Physics - Condensed Matter, 2005, 17[22], S2247-53