In-situ Annealing of Radiated Low Gain Avalanche Detector for Performance Recovery

Abstract

Conventional isothermal annealing is helpful to performance recovery of radiated silicon detector; but it is hard to be applied in vast well-installed detectors in high energy physics experiments. This summary investigated an in-situ annealing technique that employs joule heat of the intrinsic p-n junction to mitigate radiation damage effect on low gain avalanche detector (LGAD). The LGADs are 2 × 2 array with each pad of 1.3 mm × 1.3mm active area and were irradiated by 2 MeV proton to an equivalent fluence of 5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> neq/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . After being applied a forward current of 1 A lasting for 27 s, which reached a peak annealing temperature around 180°C, the leakage current, the full depletion voltage and the gain of the radiated LGADs were restored partially. The leakage current was decreased about an order of magnitude, the full depletion voltage increased from 20 V to 85 V, and the gain increased from about 6 to 11 at 400 V. This simple in-situ annealing method is possible to implement during the service period of the detectors, thus prolongs their lifetime in harsh irradiation environment.