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×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 had either a single layer of SiO₂ or double layers of SiO₂ and Si₃N₄ , in combination with the surface passivation of SiO₂ or Si₃N₄. The detectors were irradiated at room temperature by 500 MeV protons at TRIUMF to a fluence of 5.7×10 ¹³ 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