Tracking and timing measurements on irradiated TI-LGADs

Abstract

Trench-isolated (TI) LGADs, developed at FBK, are pixelated LGAD implementations where pads are separated by physical trenches etched within the silicon substrate and filled with a dielectric material. Developed as a solution to the LGAD fill factor problem, this technology provides a path towards 4D tracking with reduced inefficiencies in the interpad regions. Through a dedicated 120 GeV SPS pion test beam campaign, the time resolution, efficiency, and inter-pad distance of carbon infused irradiated TI-LGADs is presented. Fluences up to 2.5$~$x$~$$10^{15}$$~$n$_{\text{eq}}$$~$cm$^{-2}$ are evaluated, for single trench implementations with varied trench width at a temperature of -25 $^o$C. The results show an interpad distance degradation with the irradiation of the detector and an optimal time resolution between 35 ps and 45 ps for all studied devices.