Study of radiation damage in silicon detectors for high ... - F9

4. Time Development ofDefects 79An extensive study of reverse annealing was performed to unveil the nature of theresponsible process. While from most of the samples no conclusive evidence could beobtained due to bias-eect interference (see chapter 6), a dedicated set of 8 unbiasedsamples annealed at 20 C is clearly showing a linear dependence of initial slope of N effreverse annealing on irradiation uence. Thus at least during the initial stage of thereverse annealing, relevant for the LHC operation, the reaction dynamics is described bya rst order process. Further studies are however necessary to determine the inuence ofreverse bias on the reverse annealing constants.Reverse leakage current shows similar short-term annealing behaviour to that ofN eff . In agreement with results from previous sources [46, 21, 19, 14, 18] no reverse annealingwas observed. Long term annealing at 60 Chowever does not lead to the expectedsaturation of reverse current, but shows continuous annealing with an eective logarithmictime dependence. The true nature of this eect is at the present not understood.