EPD Seminar

Title: Compensated LGAD sensors for extreme radiation environments

Abstract: Silicon sensors have been extensively exploited in high-energy physics experiments in the past 40 years, from their first use in NA11 at the SPS (CERN) to their application in the present-day design of very large particle trackers. The capability of silicon sensors to work in environments with high radiation levels has been of utmost importance for experiments at accelerating machines with very energetic and intense particle beams. Presently available silicon sensors can operate efficiently up to particle fluences of 2×1016 particles/cm2, while future frontier accelerators envisage the use of silicon sensors in environments with fluences exceeding 5×1017 particles/cm2. If not overcome, this gap will prevent the use of silicon sensors in future hadron-collider experiments. The development aims at (i) understanding and modelling the mechanisms of radiation damage up to the fluence of 5E17/cm2 and (ii) designing, producing, and testing an innovative type of silicon sensor able to operate efficiently up to that fluence value. The innovative sensor design relies on the use of a thin active bulk, 20–40 μm, coupled with the mechanism of internal gain of 10–20 that will generate signals large enough to ensure detection up to the highest fluence. This breakthrough will become possible thanks to a new design of the implant responsible for signal multiplication, obtained by the compensation of p- and n-type dopants. The results already achieved and the steps envisaged up to the target accomplishment will be presented and discussed.

About the speaker: Valentina Sola am an experimental physicist working in the field of high-energy particle physics. She has worked at the HERA ep collider at DESY within the ZEUS Collaboration, and now she is a member of the CMS Collaboration at the Large Hadron Collider at CERN. Presently, she is involved in the development of new silicon sensors and their design, and participates in the construction of the MIP Timing Detector for the CMS Experiment. Valentina Sola was the Principal Investigator diverse projects to investigate the usage of thin sensors with internal gain for extreme fluence environments, as the INFN Project for Young Researchers Silicon Sensor for Extreme Fluences (eXFlu), the AIDAinnova Blue Sky Project Thin Silicon Sensor for Extreme Fluences (eXFlu-innova), and of A Compensated Design of Thin Silicon Sensors for Extreme Fluences (ComonSens), funded by the Italian Minister of University and research. Now she is the PI of an ERC Consolidator Grant on Doping Compensation in Thin Silicon Sensors: the pathway to Extreme Radiation Environments (CompleX).

Title: Radiation damage effects on the gain region in Silicon and 4H-SiC Low Gain Avalanche Diodes (LGADs)

Abstract: Over the past decade, the search for 4D (resolvable in both time and space) detectors with high radiation hardness and robustness has been one of the major challenges in experimental high-energy physics. Radiation-induced doping removal in the gain implant is one of the main limitations to the long-term operation of Low-Gain Avalanche Diodes (LGADs) in harsh radiation environments. In this contribution, a novel methodology for quantifying doping removal by analyzing irradiation-induced variations in sheet resistance measured with van der Pauw test structures will be presented. Validation is performed through TCAD simulations calibrated with Secondary Ion Mass Spectrometry (SIMS), demonstrating a nearly two-fold faster removal of donors compared to acceptors. Moreover, the demand for radiation-hard 4D detectors capable of simultaneous high-precision timing and spatial resolution is driving the investigation of 4H-Silicon Carbide (4H-SiC) as a robust alternative to silicon. In the second part of this contribution an extensive performance evaluation of 4H-SiC LGADs and PN junction diodes fabricated by Onsemi on 6-inch wafers (50 µm epitaxial layer, doping of the order of 5×1013 cm-3) will be presented. The devices were subjected to 23 MeV proton irradiation, covering five fluences from 1×1014 p/cm2 to 2×1015 p/cm2. They have been characterized in terms of I-V, C-V, TCT and beta measurements. Effect of temperature up to 200°C on I-V, C-V and up to 50-60°C on beta and TCT measurements will be shown to study and investigate the defect dynamic as a function of temperature.

About the speaker: Francesco Moscatelli received his M.Sc. in Physics (2000) and Ph.D. in Information Engineering (2003) from the University of Perugia, Italy. He worked at IMM-CNR, Bologna, from 2009 to 2017 and has been a Researcher at IOM-CNR, Perugia, since 2017. His research focuses on the design, simulation, fabrication, and characterization of semiconductor devices for particle detection and power electronics, particularly silicon and silicon carbide technologies. His work includes SiC particle detectors, 4H-SiC MOSFETs, SPADs, silicon nanowires, and LGADs. Since 2014, he has contributed to the CMS Phase-2 upgrade, overseeing process quality control for Outer Tracker silicon sensors. He has coordinated several national and international projects, including the PRIN projects 4DInSiDe, ComonSens, and HiEnD, and served as INFN Perugia CMS Local Coordinator (2019–2023) and AIDAinnova Local Coordinator (2021–2025). Since 2026, he has coordinated the INFN national project SiC_4Gain on ion-implanted 4H-SiC LGADs. Dr. Moscatelli has co-authored more than 600 publications. His current research interests include radiation detectors, silicon and SiC devices, TCAD simulation, radiation effects, and advanced semiconductor technologies for high-energy physics.

zoom meeting ID: 9750 1431 568

password: 261019