Proton irradiation on AC-coupled silicon microstrip detectors

To test the radiation tolerance of full-size detectors, four large-area AC-coupled single-sided silicon microstrip detectors were fabricated. The detectors had a size of 6 cm x 3.4 cm and were made out of a 300 μm thick, high-resistivity, n-type silicon, simulating the p-side of the double-sided silicon microstrip detectors being developed. The AC coupling layer either a single layer of SiO2 or double layers of SiO2 and in combination with the surface passivation of SiO2 Si3N4, or Si3N4. The detectors were irradiated at room temperature by 500 MeV protons at TRIUMF to a fluence of 5.7 x 1013 protons/cm2, promptly stored at 0 C after irradiation, and periodically measured over the following year. The full depletion voltages showed a substantial annealing and a gradual anti-annealing. The result was compared with the predictions of existing damage parameterization. Time variation of other characteristics, such as leakage current, interstrip and coupling capacitances, and strip-edge microdischarges was also followed