The behavior of leakage current and depletion voltage were studied on Si diodes of different resistivity during the full annealing period after 34MeV proton irradiation. After the irradiation the measurements were performed after heating the samples to cover the complete annealing curve. The hardness factor was estimated through the measurement of the diode leakage current as a function of annealing time. The diode leakage current and depletion voltage values showed a significant decrease as a function of time after heating at high temperatures. This effect was typical of bistable defects. The defect could be activated by illumination, forward bias and further heating. The average time constant of the de-activation process was found to be 4h, independently of the activation process.

Study of Bistable Defects Created after High-Temperature Annealing in 34MeV Proton Irradiated Si Diodes. D.Creanza, D.Giordano, M.de Palma, L.Fiore, N.Manna, S.My, V.Radicci, P.Tempesta: Nuclear Instruments and Methods in Physics Research Section A, 2004, 530[1-2], 128-33