Radiation damage studies of silicon microstrip sensors

Various types of large area silicon microstrip detectors were fabricated for development of radiation-tolerant detectors operational in the LHC ATLAS SCT. The detectors were irradiated with 12-GeV protons at KEK to fluences of 1.7×10¹⁴ and 4.2×10¹⁴ protons/cm². Irradiated samples include n-on-n detectors with 4 kΩ cm bulk resistivity and p-on-n detectors with 1 kΩ cm and 4 kΩ cm bulk resistivities. Four patterns of p-stop structures are configured in the n-on-n detectors. Although Hamamatsu fabricated most of the detectors, included are p-on-n detectors by SINTEF, and those fabricated in modified process by Hamamatsu. The performances after irradiation are compared through the probability of creation of faulty coupling capacitors, C-V characteristics, charge collection curves, and total leakage current. The p-on-n are similar to n-on-n detectors in these performances, and are operational in the ATLAS radiation environment