In this paper we present the numerical simulation of silicon detectors with internal gain as the main tool for 4-dimensional (4D) particle trackers design and optimization. The Low-Gain Avalanche ...Diode (LGAD) technology and its present limitations are reviewed with the aim of introducing the Resistive AC-Coupled Silicon Detectors (RSD) paradigm as a case study of our investigation. Authors here present Spice-like and 2D/3D Technological Computer-Aided Design (TCAD) simulations to characterize sensors in terms of both their electrostatic behavior, capacitive (dynamic) coupling and radiation-hardness performances, showing the methodological approach used in order to extract the set of layout rules allowing the release of RSD1, the incoming production run at Fondazione Bruno Kessler (FBK) of next-generation silicon detectors for 4D tracking with intrinsic 100% fill-factor.
This paper presents the principles of operation of Resistive AC-Coupled Silicon Detectors (RSDs) and measurements of the temporal and spatial resolutions using a combined analysis of laser and beam ...test data. RSDs are a new type of n-in-p silicon sensor based on the Low-Gain Avalanche Diode (LGAD) technology, where the n+ implant has been designed to be resistive, and the read-out is obtained via AC-coupling. The truly innovative feature of RSD is that the signal generated by an impinging particle is shared isotropically among multiple read-out pads without the need for floating electrodes or an external magnetic field. Careful tuning of the coupling oxide thickness and the n+ doping profile is at the basis of the successful functioning of this device. Several RSD matrices with different pad width-pitch geometries have been extensively tested with a laser setup in the Laboratory for Innovative Silicon Sensors in Torino, while a smaller set of devices have been tested at the Fermilab Test Beam Facility with a 120 GeV/c proton beam. The measured spatial resolution ranges between 2.5μm for 70–100 pad-pitch geometry and 17μm with 200–500 matrices, a factor of 10 better than what is achievable in binary read-out (binsize∕12). Beam test data show a temporal resolution of ∼40ps for 200 μm pitch devices, in line with the best performances of LGAD sensors at the same gain.
First FBK production of 50 μm ultra-fast silicon detectors Sola, V.; Arcidiacono, R.; Boscardin, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2019, Letnik:
924
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Fondazione Bruno Kessler (FBK, Trento, Italy) has recently delivered its first 50 μm thick production of Ultra-Fast Silicon Detectors (UFSD), based on the Low-Gain Avalanche Diode design. These ...sensors use high resistivity Si-on-Si substrates, and have a variety of gain layer doping profiles and designs based on Boron, Gallium, Carbonated Boron and Carbonated Gallium to obtain a controlled multiplication mechanism. Such variety of gain layers will allow identifying the most radiation hard technology to be employed in the production of UFSD, to extend their radiation resistance beyond the current limit of ϕ∼ 1015 neq/cm2. In this paper, we present the characterisation, the timing performance, and the results on radiation damage tolerance of this new FBK production.
Design optimization of the UFSD inter-pad region Siviero, F.; Arcidiacono, R.; Borghi, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
April 2024, 2024-04-00, 2024-04-01, Letnik:
1061, Številka:
C
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This paper reports on a measurement campaign to characterize the inter-pad region of Ultra-Fast Silicon Detectors (UFSDs) manufactured by Fondazione Bruno Kessler. The devices under test are either ...pixel or strip arrays, featuring a large number of different inter-pad layouts; both pre-irradiation and irradiated sensors have been measured. The aim of the study is to link the design parameters of the inter-pad region to the operation of the sensors, providing insights into the design of UFSD arrays with narrow inter-pad gaps. We concluded that, in the UFSD design, the doping level and the area of the p-stop should be kept low, in order to avoid the early breakdown of the device and the micro-discharges effect; UFSDs with such characteristics proved also rather insensitive to floating pads and irradiation. Thanks to these findings, it was possible to design a UFSD array that yields the expected performance with an inter-pad width as small as 25 μm, significantly improving its fill factor with respect to standard designs. Two innovative experimental techniques are presented in this work: the first one is based on a TCT setup, the second makes use of an ultra-low light CCD camera.
The very high radiation fluences expected at the high-luminosity large hadron collider (LHC) impose new challenges in terms of design of radiation resistant silicon detectors. The choice to use ...p-type substrates to improve the charge collection efficiency involves an optimization of the strip isolation to interrupt the inversion layer between the n± implants, limiting the breakdown voltage. To this purpose, TCAD modeling and simulation schemes, already developed and validated at typical LHC fluences have to be adapted to take into account effects usually neglected at lower fluences. To better understand in a comprehensive framework, the complex and articulated phenomena related to bulk and surface radiation damage, measurements on test structures and sensors, as well as TCAD simulations related to bulk, surface and interface effects, have been carried out. In particular, we have studied the properties of the SiO 2 layer and of the Si-SiO 2 interface, using MOS capacitors and gate-controlled diodes (gated diodes) manufactured by different vendors on a high-resistivity p-type silicon before and after irradiation with X-rays in the range from 50 krad to 10 Mrad. In this paper, we present the results of the experimental characterizations as well as the simulation findings, in order to analyze the effects of the interface traps on the strip isolation. This analysis helps us to validate the model and to identify the most sensitive technological and design parameters to be optimized for the design of advanced 2-D and 3-D silicon radiation detectors.
Design optimization of ultra-fast silicon detectors Cartiglia, N.; Arcidiacono, R.; Baselga, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2015, Letnik:
796
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Low-Gain Avalanche Diodes (LGAD) are silicon detectors with output signals that are about a factor of 10 larger than those of traditional sensors. In this paper we analyze how the design of LGAD can ...be optimized to exploit their increased output signal to reach optimum timing performances. Our simulations show that these sensors, the so-called Ultra-Fast Silicon Detectors (UFSD), will be able to reach a time resolution factor of 10 better than that of traditional silicon sensors.
Three-dimensional detectors for neutron imaging Mendicino, R.; Dalla Betta, G.-F.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2018, Letnik:
878
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Solid-state sensors fabricated with 3D technologies and coupled to different neutron converter materials have been developed by several groups as direct replacement of 3He gas detectors, mainly for ...homeland security applications. Results so far achieved in terms of detection efficiency are quite good (up to ≃50%) and, combined with the intrinsic excellent position resolution of silicon sensors, could lead to high performance neutron imaging systems. In this paper, we review the state of the art in three-dimensional silicon sensors for thermal-neutron detection, addressing the most promising solutions for neutron imaging. Moreover, selected results from the developments at the University of Trento on 3D pixelated detectors having relatively low fabrication complexity and expected high neutron detection efficiency up to 30% will be reported.
•A review of the main semiconductor detectors for thermal neutron imaging is reported.•Results so far achieved and pros and cons of the different approaches are discussed.•Neutron detectors developed at the University of Trento promise high performance.
Tracking in 4 dimensions Cartiglia, N.; Arcidiacono, R.; Baldassarri, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2017, Letnik:
845, Številka:
C
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In this contribution we will review the progresses toward the construction of a tracking system able to measure the passage of charged particles with a combined precision of ∼10ps and ∼10μm, either ...using a single type of sensor, able to concurrently measure position and time, or a combination of position and time sensors.
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