The second production of RSD (AC-LGAD) at FBK

TL;DR

This paper reports on the second production run of Resistive AC-Coupled Silicon Detectors (RSD) at FBK, highlighting design improvements and performance characteristics for 4D particle tracking applications.

Contribution

It introduces the design and fabrication of the second RSD batch, enhancing spatial reconstruction and timing performance for LGAD-based detectors.

Findings

Successful fabrication of RSD2 with optimized AC-electrode layout

Improved spatial and timing resolution demonstrated in tests

Design principles for signal confinement and hit position reconstruction

Abstract

In this contribution we describe the second run of RSD (Resistive AC-Coupled Silicon Detectors) designed at INFN Torino and produced by Fondazione Bruno Kessler (FBK), Trento. RSD are n-in-p detectors intended for 4D particle tracking based on the LGAD technology that get rid of any segmentation implant in order to achieve the 100% fill-factor. They are characterized by three key-elements, (i) a continuous gain implant, (ii) a resistive n-cathode and (iii) a dielectric coupling layer deposited on top, guaranteeing a good spatial reconstruction of the hit position while benefiting from the good timing properties of LGADs. We will start from the very promising results of our RSD1 batch in terms of tracking performances and then we will move to the description of the design of the RSD2 run. In particular, the principles driving the sensor design and the specific AC-electrode layout adopted to optimize the signal confinement will be addressed.