TCAD investigation of Compensated LGAD Sensors for extreme fluence

A new gain layer design, whose effective doping profile results from the difference between two overlapping implants of opposite dopant species (e.g. boron and phosphorus), is conceived to extend the operational life of Low-Gain Avalanche Diodes (LGADs) to fluences significantly above the present limit of 2.5⋅10151MeVneq/cm2. Both acceptor and donor atoms will experience doping removal due to irradiation, but their difference will remain fairly constant. The implementation of this ambitious goal necessitates a meticulous process of optimizing the two implants that constitute the gain layer of the Compensated LGADs. To this end, the Synopsys® Sentaurus TCAD toolkit, with the most up-to-date release of the Perugia radiation damage model, was employed, enabling a comprehensive investigation of these new sensors. This level of scrutiny is crucial for understanding the behaviour of the first Compensated LGAD production (2022 by FBK) and designing the subsequent batches of Compensated LGADs.