Innovative DC-coupled Resistive Silicon Detector for 4D tracking

TL;DR

This paper introduces the DC-coupled Resistive Silicon Detector (DC-RSD), a novel 4D tracking sensor combining LGAD and resistive read-out technologies, with initial promising performance results from laboratory and beam tests.

Contribution

It presents the design, fabrication, and initial testing of the first DC-RSD prototype, demonstrating a new approach for silicon sensors in 4D tracking applications.

Findings

Successful laser TCT characterization

Initial beam test results at DESY

Effective signal containment within electrodes

Abstract

In the past 10 years, two design innovations, the introduction of low internal gain (LGAD) and of resistive read-out (RSD), have radically changed the performance of silicon detectors. The LGAD mechanism, increasing the signal-to-noise ratio by about a factor of 20, leads to improved time resolution (typically 30 ps for a 50-$\mu$m thick sensor), while resistive read-out, sharing the collected charge among read-out electrodes, leads to excellent spatial resolution even using large pixels (about 15 $\mu$m for 450-$\mu$m pixel size). This contribution outlines the design strategy and presents the first performance results of the latest evolution of silicon sensors for 4D tracking, the DC-coupled Resistive Silicon Detector (DC-RSD). The DC-RSD is a thin LGAD with a DC-coupled resistive read-out. This design leads to signal containment within a predetermined number of electrodes using isolating trenches (TI technology). Several test structures and application-oriented devices have been implemented in the wafer layout. The sensors, produced at Fondazione Bruno Kessler (FBK) in the framework of the 4DSHARE project, have been characterized with a laser TCT system and recently tested at DESY with an electron beam. The study of this first prototype production will provide us with immediate feedback on the soundness of the DC-RSD concepts.