Design and optimisation of radiation resistant AC- and DC-coupled resistive LGADs

TL;DR

This paper presents the design, simulation, and optimization of radiation-resistant AC- and DC-coupled resistive LGADs for high-energy physics, highlighting improvements in uniformity and performance based on TCAD simulations.

Contribution

It introduces a new DC-coupled resistive LGAD design and provides simulation-guided optimization, advancing detector performance and uniformity.

Findings

Achieved 38 ps temporal resolution with prototypes

Demonstrated improved uniformity with DC coupling

Guided design through TCAD simulations

Abstract

Future high-energy physics experiments require a paradigm shift in radiation detector design. In response to this challenge, resistive LGADs that combine Low Gain Avalanche Diode technology with resistive readout have been developed. The prototypes created so far, employing AC-coupled contacts, have demonstrated impressive performance, achieving a temporal resolution of 38 ps and a spatial resolution of 15 $\mu$m with a pixel pitch of 450 $\mu$m. To tackle some of the issues encountered up to this point, particularly the non-uniform response across the entire surface of the detector, a new version with DC-coupled contacts has recently been developed. The Synopsys Sentaurus TCAD simulations that have guided the design of their first production, released by the Fondazione Bruno Kessler in November 2024, will be presented below along with a concise summary of the history of the prototypes with AC-coupled contacts.