Design and Fabrication of an Optimum Peripheral Region for Low Gain Avalanche Detectors

摘要

Low Gain Avalanche Detectors (LGAD) represent a remarkable advance in highenergy particle detection, since they provide a moderate increase (gain ~10) ofthe collected charge, thus leading to a notable improvement of thesignal-to-noise ratio, which largely extends the possible application ofSilicon detectors beyond their present working field. The optimum detectionperformance requires a careful implementation of the multiplication junction,in order to obtain the desired gain on the read out signal, but also a properdesign of the edge termination and the peripheral region, which prevents theLGAD detectors from premature breakdown and large leakage current. This workdeals with the critical technological aspects when optimising the LGADstructure. The impact of several design strategies for the device periphery isevaluated with the aid of TCAD simulations, and compared with the experimentalresults obtained from the first LGAD prototypes fabricated at the IMB-CNM cleanroom. Solutions for the peripheral region improvement are also provided.