Measurements and TCAD simulations of innovative RSD and DC-RSD LGAD devices for future 4D tracking

TL;DR

This paper presents beam test results and detailed TCAD simulations of innovative RSD and DC-RSD LGAD sensors, demonstrating their potential for high-precision 4D tracking in future particle physics experiments.

Contribution

It introduces the design and simulation of DC-RSD LGAD sensors, advancing the RSD technology for improved spatial resolution and detector performance.

Findings

Achieved a position resolution of 15 microns in beam tests.

Validated the DC-RSD design through comprehensive 3D TCAD simulations.

Informed the first production of DC-RSD sensors at FBK.

Abstract

This paper summarizes the beam test results obtained with a Resistive Silicon Detector (RSD) (also called AC-Low Gain Avalanche Diode, AC-LGAD) pixel array tested at the DESY beam test facility with a 5 GeV/c electron beam. Furthermore, it describes in detail the simulation results of DC-RSD, an evolution of the RSD design. The simulations campaign described in this paper has been instrumental in the definition of the structures implemented in the Fondazione Bruno Kessler FBK first DC-RSD production. The RSD matrix used in this study is part of the second FBK RSD production, RSD2. The best position resolution reached in this test is sigma_x = 15 micron, about 3.4% of the pitch. DC-RSD LGAD, are an evolution of the AC-coupled design, eliminating the dielectric and using a DC-coupling to the electronics. The concept of DC-RSD has been finalized using full 3D Technology-CAD simulations of the sensor behavior. TCAD simulations are an excellent tool for designing this innovative class of detectors, enabling the evaluation of different technology options (e.g., the resistivity of the n+ layer, contact materials) and geometrical layouts (shape and distance of the read-out pads).