arXiv subjects

F. Moscatelli

Publications and source records attributed to F. Moscatelli.

12 recordsLinked to original sources

arXiv2026

Comparison of Silvaco and Synopsys TCAD Predictions Including the Perugia Radiation Damage Model in Silicon Pixel Detectors for the HL-LHC

At the High Luminosity Large Hadron Collider (HL-LHC), silicon pixel detectors will be exposed to radiation fluences about 5 to 10 times larger than those experienced by the current innermost pixel layers up to today. Due to radiation damage to bulk of pixel detectors, leakage current and depletion voltage will increase significantly over time, posing severe constraints on operating conditions, with important modifications to the electric field profile due to radiation induced deep defects in silicon bulk. It is important to have reliable predictions for all observables - such as leakage current level and breakdown voltage - after irradiation, in order to estimate operational voltage values. In this paper, the predictions of Silvaco and Synopsys TCAD device simulations are compared when the surface and bulk defects and traps of the ``New University of Perugia radiation damage model'' are included by studying observables like leakage current, depletion and breakdown voltage, along with electric field and trap occupancy profiles. The results are quite promising regarding leakage current, depletion voltage, electric field and trap statistics, at two distinct reference temperatures and fluences.

physics.ins-det↗

arXiv2025

A two-prong Approach to the Simulation of DC-RSD: TCAD and Spice

The DC-coupled Resistive Silicon Detectors (DCRSD) are the evolution of the AC-coupled RSD (RSD) design, both based on the Low-Gain Avalanche Diode (LGAD) technology. The DC-RSD design concept intends to address a few known issues present in RSDs (e.g., baseline fluctuation, long tail-bipolar signals) while maintaining their advantages (e.g., signal spreading, 100% fill factor). The simulation of DC-RSD presents several unique challenges linked to the complex nature of its design and the large pixel size. The defining feature of DC-RSD, charge sharing over distances that can be as large as a millimeter, represents a formidable challenge for Technology-CAD (TCAD), the standard simulation tool. To circumvent this problem, we have developed a mixed-mode approach to the DC-RSD simulation, which exploits a combination of two simulation tools: TCAD and Spice. Thanks to this hybrid approach, it has been possible to demonstrate that, according to the simulation, the key features of the RSD, excellent timing and spatial resolutions (few tens of picoseconds and few microns), are maintained in the DC-RSD design. In this work, we present the developed models and methodology, mainly showing the results of device-level numerical simulation, which have been obtained with the state-of-the-art Synopsys Sentaurus TCAD suite of tools. Such results will provide all the necessary information for the first batch of DC-RSD produced by Fondazione Bruno Kessler (FBK) foundry in Trento, Italy.

hep-ex↗

arXiv2025

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

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).

physics.ins-det↗

arXiv2025

Innovative DC-coupled Resistive Silicon Detector for 4D tracking

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.

physics.ins-det↗

arXiv2023

Characterization of hydrogenated amorphous silicon sensors on polyimide flexible substrate

Hydrogenated amorphous silicon (a-Si:H) is a material having an intrinsically high radiation hardness that can be deposited on flexible substrates like Polyimide. For these properties a-Si:H can be used for the production of flexible sensors. a-Si:H sensors can be successfully utilized in dosimetry, beam monitoring for particle physics (x-ray, electron, gamma-ray and proton detection) and radiotherapy, radiation flux measurement for space applications (study of solar energetic particles and stellar events) and neutron flux measurements. In this paper we have studied the dosimetric x-ray response of n-i-p diodes deposited on Polyimide. We measured the linearity of the photocurrent response to x-rays versus dose-rate from which we have extracted the dosimetric x-ray sensitivity at various bias voltages. In particular low bias voltage operation has been studied to assess the high energy efficiency of these kind of sensor. A measurement of stability of x-ray response versus time has been shown. The effect of detectors annealing has been studied. Operation under bending at various bending radii is also shown.

physics.ins-det↗

arXiv2023

Resistive Read-out in Thin Silicon Sensors with Internal Gain

Two design innovations, low-gain avalanche (Low-Gain Avalance Diode, LGAD) and resistive read-out (Resistive Silicon Detector, RSD), have brought strong performance improvements to silicon sensors. Large signals, due to the added gain mechanism, lead to improved temporal precision, while charge sharing, introduced by resistive read-out, allows for achieving excellent spatial resolution even with large pixels. LGAD- and RSD- based silicon sensors are now adopted, or considered, in several future experiments and are the basis for almost every next 4D-trackers. New results obtained with sensors belonging to the second FBK production of RSD (RSD2) demonstrate how a combined resolution of 30 ps and 30 \microns can be obtained with pixels as large as $1 \times 1 $ mm$^2$.

physics.ins-det↗

arXiv2022

Simulations of Silicon Radiation Detectors for High Energy Physics Experiments

Silicon radiation detectors are an integral component of current and planned collider experiments in high energy physics. Simulations of these detectors are essential for deciding operational configurations, for performing precise data analysis, and for developing future detectors. In this white paper, we briefly review the existing tools and discuss challenges for the future that will require research and development to be able to cope with the foreseen extreme radiation environments of the High Luminosity runs of the Large Hadron Collider and future hadron colliders like FCC-hh and SPPC.

physics.ins-det↗

arXiv2022

Development of thin hydrogenated amorphous silicon detectors on a flexible substrate

The HASPIDE (Hydrogenated Amorphous Silicon PIxels DEtectors) project aims at the development of thin hydrogenated amorphous silicon (a-Si:H) detectors on flexible substrates (mostly Polyimide) for beam monitoring, neutron detection and space applications. Since a-Si:H is a material with superior radiation hardness, the benefit for the above-mentioned applications can be appreciated mostly in radiation harsh environments. Furthermore, the possibility to deposit this material on flexible substrates like Polyimide (PI), polyethylene naphthalate (PEN) or polyethylene terephthalate (PET) facilitates the usage of these detectors in medical dosimetry, beam flux and beam profile measurements. Particularly interesting is its use when positioned directly on the flange of the vacuum-to-air separation interface in a beam line, as well as other applications where a thin self-standing radiation flux detector is envisaged. In this paper, the HASPIDE project will be described and some preliminary results on PI and glass substrates will be reported.

physics.ins-det↗

arXiv2022

Solid State Detectors and Tracking for Snowmass

Tracking detectors are of vital importance for collider-based high energy physics (HEP) experiments. The primary purpose of tracking detectors is the precise reconstruction of charged particle trajectories and the reconstruction of secondary vertices. The performance requirements from the community posed by the future collider experiments require an evolution of tracking systems, necessitating the development of new techniques, materials and technologies in order to fully exploit their physics potential. In this article we summarize the discussions and conclusions of the 2022 Snowmass Instrumentation Frontier subgroup on Solid State and Tracking Detectors (Snowmass IF03).

physics.ins-det↗

arXiv2022

Testing of planar hydrogenated amorphous silicon sensors with charge selective contacts for the construction of 3D- detectors

Hydrogenated Amorphous Silicon (a-Si:H) is a material well known for its intrinsic radiation hardness and is primarily utilized in solar cells as well as for particle detection and dosimetry. Planar p-i-n diode detectors are fabricated entirely by means of intrinsic and doped PECVD of a mixture of Silane (SiH4) and molecular Hydrogen. In order to develop 3D detector geometries using a-Si:H, two options for the junction fabrication have been considered: ion implantation and charge selective contacts through atomic layer deposition. In order to test the functionality of the charge selective contact electrodes, planar detectors have been fabricated utilizing this technique. In this paper, we provide a general overview of the 3D fabrication project followed by the results of leakage current measurements and x-ray dosimetric tests performed on planar diodes containing charge selective contacts to investigate the feasibility of the charge selective contact methodology for integration with the proposed 3D detector architectures.

physics.ins-det↗

arXiv2016

Measurements and TCAD Simulations of Bulk and Surface Radiation Damage Effects in Silicon Detectors

In this work we propose the application of a radiation damage model based on the introduction of deep level traps/recombination centers suitable for device level numerical simulation of radiation detectors at very high fluences (e.g. 1÷2 10^16 1-MeV equivalent neutrons per square centimeter) combined with a surface damage model developed by using experimental parameters extracted from measurements from gamma irradiated p-type dedicated test structures.

physics.ins-det↗

arXiv2016

Combined Bulk and Surface Radiation Damage Effects at Very High Fluences in Silicon Detectors: Measurements and TCAD Simulations

In this work we propose a new combined TCAD radiation damage modelling scheme, featuring both bulk and surface radiation damage effects, for the analysis of silicon detectors aimed at the High Luminosity LHC. In particular, a surface damage model has been developed by introducing the relevant parameters (NOX, NIT) extracted from experimental measurements carried out on p-type substrate test structures after gamma irradiations at doses in the range 10-500 Mrad(Si). An extended bulk model, by considering impact ionization and deep-level cross-sections variation, was included as well. The model has been validated through the comparison of the simulation findings with experimental measurements carried out at very high fluences (2 10^16 1 MeV equivalent n/cm^2) thus fostering the application of this TCAD approach for the design and optimization of the new generation of silicon detectors to be used in future HEP experiments.

physics.ins-det↗