Radiation damage effects at High Luminosity LHC (HL-LHC) fluences greater than 2.2×1016n∕cm2 1 MeV equivalent and total ionizing doses (TID) greater than 1 Grad will impose very stringent constraints ...in terms of radiation resistance of solid-state detectors. To cope with this design challenge, TCAD tools can be used to study different technology and design options, in order to optimize the performance of silicon detectors in terms of inter-electrode isolation and charge collection properties. A comprehensive modeling approach based on combined bulk and surface damage effects accounting for a limited number of measurable parameters needs therefore to be developed and validated over different technology options. In this work, we mainly focus on the effects of surface damage on detectors fabricated on p-type substrates by different providers. Actually, starting from standard test structure measurements (i.e. MOS capacitors, gated diodes), the integrated interface trap state density (NIT) and the oxide charge (QOX) can be extracted for different vendors and used as input parameter to the simulation tools. Test structures under study include MOS capacitors, gated-diodes, fabricated both at Hamamatsu Photonics (Japan) and at Infineon (Austria). Using High-Frequency (HF) and Quasi-Static (QS) C–V characteristics and current–voltage (I–V) measurements, the effective oxide charge density (NEFF), the surface generation velocity (s0) and the interface trap density (DIT) have been determined and compared for the two technologies before and after irradiation with X-rays with doses ranging from 0.05 to 20 Mrad(SiO2). A detailed simulation analysis on MOS capacitor capacitances and gated diode currents has been carried out, varying the previously mentioned parameters, with the aim to evaluate the effects of oxide charge density and interface trap density increase with the dose. The separate effects of different types of interface trap states have been considered as well, by varying one by one the total density of donor- and acceptor-type trap states, respectively. The effects of different trap energy distributions and capture cross sections have been evaluated within Synopsys Sentaurus TCAD device simulator by means of steady-state, AC and transient analyses. The good agreement obtained for both vendors would support the use of the model as a predictive tool to optimize the design and the operation of novel solid-state detectors in the HL-LHC scenario.
•Measurements of surface damage effects on different test structures (HPK, IFX, FBK).•TCAD simulation of MOS capacitances and gated diode currents.•Modeling scheme able to reproduce the device electrical behavior vs. irradiation dose.•Perspective application as a predictive tool to optimize future HL-LHC detectors.
Fully depleted monolithic active pixel sensors (FD-MAPSs) represent a state-of-the-art detector technology and profit from a low material budget and cost for high-energy physics experiments and other ...fields of research like medical imaging and astro-particle physics. Compared to the MAPS currently in use, fully depleted pixel sensors have the advantage of charge collection by drift, which enables a fast and uniform response overall to the pixel matrix. The functionality of these devices has been shown in previous proof-of-concept productions. In this article, we describe the optimization of the test pixel designs that will be implemented in the first engineering run of the demonstrator chip of the ARCADIA project. These optimization procedures include radiation damage models that have been employed in Technology Computer Aided Design simulations to predict the sensors’ behavior in different working environments.
INFN-FBK developments of 3D sensors for High-Luminosity LHC Oide, H.; Alimonti, G.; Boscardin, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2019, Letnik:
924
Journal Article
Recenzirano
Odprti dostop
3D type of pixel sensors is a promising option for the innermost pixel layer at the High-Luminosity LHC. However, the required very high hit-rate capabilities, finer pixel granularity, extreme ...radiation hardness and reduced material budget call for a downscale of the pixel size as compared to existing 3D sensors, involving smaller pitch (e.g. 50 × 50 or 25×100μm2), shorter inter-electrode spacing (∼30μm), narrower electrodes (∼6μm diameter), and reduced active thickness (∼100–150μm). Within a joint R&D effort with INFN, FBK has produced a new generation of 3D pixel sensors with these challenging features. In this talk preliminary results from the electrical and functional characterisation of the first prototypes are reported, included their behaviour after large radiation fluence, close to the ones expected in the High Luminosity LHC environment. Prospects for the next prototypes are also presented.
In scintillation and dosimetry applications, the increasing interest on the use of colloidal quantum dots (QDs) in comparison with organic fluorophores is mainly due to their easier chemical ...processability, narrower photoluminescence (PL) emission, and higher cross-section for ionizing radiation. The development of scintillators and dosimeter based on QDs, however, relies on a deep understanding of the effects of ionizing radiation on QD structures. In this paper, we present the optical characterization of colloidal cadmium-free InGaP/ZnS core–shell QDs embedded in polydimethylsiloxane (PDMS) and irradiated with 2 MeV protons (H+) in the fluence range of 1014 to 1015 H+ cm–2. Steady-state PL measurements of the irradiated samples show a decrease of the average QD PL intensity, indicating the introduction of PL quenching centers. Time-resolved PL measurements, acquired with a time-correlated single photon counting system, provide a way to probe the radiation-induced change in the carrier recombination dynamics of the QDs. A detailed analysis of the time-resolved PL curves demonstrates the presence of PL quenching defects localized both at the inner (core) and at the outer (shell) structure of the nanocrystal. The radiation-induced change in the QD optical properties, coupled with a suitable radiation hardness of the PDMS in these irradiation conditions, open the way for possible future applications related to dosimetry systems based on QDs as nanostructured sensing elements.
In view of the LHC upgrade for the High Luminosity phase (HL-LHC), the ATLAS experiment plans to replace the Inner Detector with an all-silicon system. The n-on-p silicon technology is a promising ...candidate to achieve a large area instrumented with pixel sensors, since it is radiation hard and cost effective. The paper reports on the performance of thin 100 and 130μm n-in-p planar pixel sensors produced by FBK-CMM with active-edge technology in collaboration with LPNHE and INFN. Beam-test results are presented, with focus on the hit efficiency at the detector edge of a novel design consisting of a staggered deep trench.
In this paper, we report on the characterization of silicon 3D and planar sensors, coupled with different neutron converter materials, such as 10B, B410C and 6LiF, with different deposition ...thickness. Selected results from the electrical and functional characterization of the devices are shown and comparatively discussed with the aid of SRIM and Geant4 simulations.
The limited neutron detection efficiency, on the order of ≃ 1% (planar) and ≃ 8% (3D) from simulations, is understood, and hints for the optimization of the devices have been derived.
The INFN–FBK “Phase-2” R&D program Dalla Betta, G.-F.; Boscardin, M.; Bomben, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
Odprti dostop
We report on the 3-year INFN ATLAS–CMS joint research activity in collaboration with FBK, started in 2014, and aimed at the development of new thin pixel detectors for the High Luminosity LHC Phase-2 ...upgrades. The program is concerned with both 3D and planar active-edge pixel sensors to be made on 6” p-type wafers. The technology and the design will be optimized and qualified for extreme radiation hardness (2×1016neqcm−2). Pixel layouts compatible with present (for testing) and future (RD53 65nm) front-end chips of ATLAS and CMS are considered. The paper covers the main aspects of the research program, from the sensor design and fabrication technology, to the results of initial tests performed on the first prototypes.
Scribe–cleave–passivate (SCP) slim edge technology for silicon sensors Fadeyev, V.; Sadrozinski, H.F.-W.; Ely, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
731
Journal Article
Recenzirano
We are pursuing scribe–cleave–passivate (SCP) technology of making “slim edge” sensors. Such sensors have only a minimal amount of inactive peripheral region, which benefits construction of ...large-area tracker and imaging systems. Key application steps of this method are surface scribing, cleaving, and passivation of the resulting sidewall. We are working on developing both the technology and physical understanding of the processed devices performance. In this paper we begin by reviewing the manufacturing options of SCP technology. Then we show new results regarding the technology automation and device physics performance. The latter includes charge collection efficiency near the edge and radiation hardness study. We also report on the status of devices processed at the request of the RD50 collaborators.
We report on the design and TCAD simulations of planar p-on-n sensors with active edge aimed at a four-side buttable X-ray detector module for future FEL applications. Edge terminations with ...different number of guard rings were designed to find the best trade-off between breakdown voltage and border gap size. The methodology of the sensor design, the optimization of the most relevant parameters to maximize the breakdown voltage and the final layout are described.
The PixFEL project is conceived as the first stage of a long term research program aiming at the development of advanced X-ray imaging instrumentation for applications at the free electron laser ...(FEL) facilities. The project aims at substantially advancing the state-of-the-art in the field of 2D X-ray imaging by exploring cutting-edge solutions for sensor development, for integration processes and for readout channel architectures. The main focus is on the development of the fundamental microelectronic building blocks for detector readout and on the technologies for the assembly of a multilayer module with minimum dead area. This work serves the purpose of introducing the main features of the project, together with the simulation results leading to the first prototyping run.
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