EVALUATION OF DOUBLE-SIDED, AC-COUPLED, DOUBLE METAL-SILICON STRIP DETECTORS FOR H1 AT HERA

Prototype double sided silicon strip detectors for the H1 vertex detector have been fabricated. The design uses integrated coupling capacitors on both sides and a second metal layer with readout lines on the n-side. Measurements of leakage currents, sheet resistances, metal line quality and contact reliability all show satisfactory results. A multi-guard structure improves the high-voltage and long-term stability of the detectors. The accumulation layer channel resistors on the n-side showed dramatic radiation effects after Co-60 doses of 100 krad and an improved design with a metal gate electrode is demonstrated. Interstrip capacitances have been measured systematically on test structures with various geometries. The capacitance due to the second metal layer on the n-side has been measured for a 2 mum SiO2 and a 6 mum polyimide dielectric. Up to now, integrated coupling capacitors could not be fabricated with sufficiently low defect rates.