DC-coupled Resistive Read-out Silicon Sensors for Future 4D Tracking: Recent Advancements and First Laboratory Characterization

Recent advancements in sensor technology have paved the way for the development of high-resolution 4D-tracking detectors capable of simultaneously measuring the position and time of passage of charged particles within a single sensitive device. The key point is the use of resistive read-out in thin Low Gain Avalanche Diode (LGAD) sensors, which introduces combined intrinsic signal sharing and internal gain. This contribution focuses on the development of a thin LGAD with a DC-coupled resistive read-out (DC-coupled Resistive Silicon Detector - DC-RSD). The aim is to achieve a spatial resolution of a few micrometers and an excellent time resolution of approximately 30 ps, using relatively large pixels (150-200 micrometers), which enables detectors with low channel density and low power consumption. A strong effort has been put into the simulation of the device, supported by experimental measurements of the AC-coupled resistive read-out sensors, which can be used to extrapolate the DC-RSD performance. This contribution describes the design and implementation strategy of the first DC-RSD production, presently in progress at Fondazione Bruno Kessler. Several test structures and application-oriented devices have been designed, which will enable detailed studies of the charge sharing optimization. The production is expected to be completed in early Fall 2024. The initial characterization of the production in the laboratory will provide us with immediate feedback on the soundness of the DC-RSD concepts.