Silicon detector developments for calorimetry: Technology and radiation damage

Abstract Large area silicon detectors with a sensitive area of 5 × 5 cm 2 and a thickness of 400 μm have been developed for the instrumentation of the plug calorimeter at H1/HERA. The novel method, a combination of surface barrier and planar processes, has resulted in detectors with excellent quality and long term operation stability. A current density of down to 1 nA/cm 2 was reached. Studies of radiation damage produced by 14 MeV neutrons, 25 MeV protons and 20 keV X-rays were performed and the resulting current increase, impurity removal and charge collection deficiency investigated. Long term storage and short term heat treatments showed appreciable annealing effects by up to 94%.