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 cmx3.4 cm and were made out of a 300 [Mu]m 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 Si[O.sub.2] or double layers of Si[O.sub.2] and [Si.sub.3][N.sub.4], in combination with the surface passivation of Si[O.sub.2] or [Si.sub.3][N.sub.4]. The detectors were irradiated at room temperature by 500 MeV protons at TRIUMF to a fluence of 5.7x[10.sup.13] protons/[cm.sup.2], promptly stored at 0 [degree] 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, inter-strip and coupling capacitances, and strip-edge micro-discharges was also followed.