Ghosts in irradiated trench isolated LGADs

Abstract In this paper we present the results from the study on the self-induced (ghost) signal observed in the neutrons irradiated trench-isolated Low Gain Avalanche Diodes (TI-LGADs). This is extension of the previous research on non-irradiated TI-LGADs where an extraordinary large signal was generated without external stimulation (by laser) above a certain bias threshold. Here, the findings related to the impact of the radiation-induced defects and temperature on the ghost signals is discussed. In addition, comparison of double trench (2TR) LGADs with single trench (1TR) LGADs and standard p-type-intrinsic-n-type diodes (PINs) demonstrates the influence of the trenches configuration and gain layer on the ghost phenomenon.