Choose timezone
Your profile timezone:
3rd DRD3 week on Solid State Detectors R&D
→
Europe/Amsterdam
Nikhef, Amsterdam
Nikhef, Amsterdam
Giulio Pellegrini
(Centro Nacional de Microelectrónica (IMB-CNM-CSIC) (ES)),
Gregor Kramberger
(Jozef Stefan Institute (SI)),
Michael Moll
(CERN)
Description
| Due to strikes on Friday there will be no NS trains except for a limited service between Amsterdam Centraal and Schiphol: refer to the NS journey planner |
The 3rd DRD3 week will take place from Monday 2 June to Friday 6 June at Nikhef in Amsterdam, The Netherlands. All sessions will take place in plenary form.
Location
The plenary meeting will take place in the conference room "Turingzaal" at the Science Park Congress Center (directly next to Nikhef and the University of Amsterdam).
The collaboration board meeting will be held in the Veltman center at Nikhef (H331, third floor).
For a quick overview, please refer to this map or list.
Abstracts
The registration for abstracts is open until 23 May.
As for the last DRD3 week, we invite you to indicate the type of presentation:
Type 1 is the scientific abstract on the work done. This is the abstract you would normaly submit to the conference/workshop. Please make it sufficiently complete that the WG conveners will be able judge its content fairly.
Type 2 is the draft of the project that you want to propose for future work involving at least two contributing DRD3 member institutes. The template for proposing such projects can be found in the DRD3 public eos area.
In the abstract submission form please indicate the WG which suits best your contribution. In the form you will also find the request to specify the type of presentation (Type1 = Presentation of Scientifc Results, and Type 2=Project proposal for future work) .
Registration
For in-person participation the registration fee is € 280 including social dinner or € 200 without social dinner. This fee includes lunches (except on Monday), coffee breaks, and also covers renting of the venue. Remote participation is free.
Nikhef Local Organization Team Contact
Registration
DRD3 Registration
Zoom Meeting ID
66423856152
Host
Kazu Akiba
Alternative hosts
Kevin Heijhoff, Gregor Kramberger, Giulio Pellegrini
Useful links
Join via phone
Zoom URL
-
-
1
Registration
-
Welcome
-
2
WelcomeSpeakers: Gregor Kramberger (Jozef Stefan Institute (SI)), Martin Van Beuzekom (Nikhef National institute for subatomic physics (NL))
-
2
-
WG/WP1 - CMOS technologies: Scientific Presentations
-
3
Introduction to WG1/WP1 sessionSpeakers: Eva Vilella Figueras (University of Liverpool (GB)), Heinz Pernegger (CERN), Ingrid-Maria Gregor (DESY & Bonn University), Jerome Baudot (IPHC - Strasbourg)
-
4
Conceptual Basis for Canadian Participation in the MALTA Project: toward a Design and Verification Strategy
A consortium of Canadian researchers from Carleton and Waterloo Universities has joined the CERN-led MALTA project, a CMOS MAPS project fabricated in the 180nm TowerJazz technology node. We expect that Canadian expertise in analog mixed-signal design, Radiation Hardening by Design (RHBD) and algorithmic error correction for hardware implementation will be particularly valuable in advancing the previous MALTA design in 65 nm CMOS technology. We aim to use design concepts enhancing timing resolution, speed, radiation resilience and power consumption. There are two focus areas:
- Focus area 1: Optimization of the analog front-end (AFE) for improved timing resolution, noise performance, power efficiency and enhanced radiation resilience.
- Focus area 2: Optimization of the digital periphery for higher bandwidth and scalability to larger pixel arrays with radiation hardened by design (RBHD) registers and memories.
For the AFE optimization we propose to introduce amplifier topologies such as the folded cascode front-end taking full advantage of feature sizes and lower nominal voltage supply of 65 nm CMOS. We propose to improve the AFE performance by implementing pixel threshold equalization. The 65nm process enables calibration circuitry to be embedded within each pixel without violating area constraints. A complementary step is the development of on-chip architectures for detecting and flagging bad or noisy pixels during operation.
In the digital periphery, the aim is to simplify the integration of the MALTA chip into larger detector systems by introducing the concept of chip-to-chip serial transfer as has already been envisioned by earlier MALTA designers. In parallel, we aim to ensure reliable, high-speed operation of essential digital components (SRAM, FIFO buffers, Flip-Flops) within the MALTA sensor under significant radiation exposure. This can be achieved by implementing RHBD memory and logic cells, e.g. interlocked cell designs (DICE – Dual Interlocked Cell) optimized for power efficiency. Furthermore, by implementing Error Correcting Codes (ECC) particularly for on-chip memories (SRAM, FIFOs) one can also detect and correct radiation-induced changes of state (bit-flips) in digital memory elements.
We will present in some detail the above ideas while justifying the move to the 65nm technology mode. Where possible, experience gained from previous applications will be provided. To ensure robust performance, we will present a preliminary integration and verification strategy encompassing block-level and system-level aspects of the proposed design, while acknowledging potential challenges.
Speakers: Leonard McEchern (Carleton University), Manoj Sachdev (University of Waterloo), Thomas Koffas (Carleton University (CA)) -
5
The first prototype Monolithic Active Pixel Sensor for The OCTOPUS Project
The First Monolithic Active Pixel Sensor Prototype for The OCTOPUS Project
Fadoua Guezzi Messaoud on behalf of the OCTOPUS project
Institut Pluridisciplinaire Hubert Curien IPHC, Strasbourg, France
Email: fadoua.guezzi-messaoud@iphc.cnrs.fr
Abstract
The next generation of lepton colliders will require extremely precise vertex detectors that cannot be implemented in technologies widely used at the moment. Hence it is essential to explore novel, small feature size monolithic approaches.
The OCTOPUS (Optimized CMOS Technology for Precision in Ultra-thin Silicon) project, part of the DRD3 collaboration, unites physicists and ASIC designers across Europe pushing the technology forward. In a first stage, the project aims to develop a MAPS chip that serves as vertex detector demonstrator developed in the TPSCo 65nm CIS process. The contribution sketches the development targets and discusses the functionality and layout of the first planned prototype and evaluates the potential expected performance of the chip.
For the first prototype, we aim at a spatial resolution of 3 µm, about 100 ns of timing accuracy, and an average power consumption below 500 mW/cm². For the final chip, we aim to meet the needs of vertex detectors in future lepton colliders by achieving a time resolution of 5 ns and an average power consumption below 50 mW/cm² while maintaining a spatial resolution of 3 µm.
Speaker: Fadoua Guezzi Messaoud (Centre National de la Recherche Scientifique (FR)) -
6
The Versatile MAPS project
The Versatile MAPS project was started in response to the needs of several collaborations for a high performance ultra-low power MAPS detector for tracking applications. While there is a common understanding on the spatial precision (about 10 µm) and on a thinning of the sensors to the typical thickness (50 µm), the requirements in terms of rate capability, power and time stamping vary significantly depending on the precise application.
The project pursues the vision of covering the different requirements with one single sensor hardware, which may be configured to different use cases by means of slow control. This goal will be reached for instance by tuning the power provided to the analogue front-ends to trade their consumption versus their response speed and by switching off bandwidth and additional building blocks whenever not required. Ultimately, rate capability and power could be adapted to the location of the device in the experiment during run time, which would allow to optimise the performance of the full detector systems to a new level.
The presentation will introduce the vision of the project, discuss its feasibility and give a first status on the formation of the related project community.
Speaker: Michael Deveaux (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE)) -
16:00
Coffee/Tea break
-
7
1 ns to 100 ps timing precision architecture (PMaTT) in TPSCo 65nm with Update on NAPA and TDC @ SLACSpeakers: Caterina Vernieri (SLAC National Accelerator Laboratory (US)), Didier Claude Contardo (Centre National de la Recherche Scientifique (FR))
-
8
Status of the non amplified MiniCactus V2 chip in LF15A technology and first steps towards sensors with intrinsic amplification.
The Cactus and MiniCactus chip series are demonstrator sensors optimized for precision time measurement of the time of arrival of charged particles. Their goal is to explore the performance that can be obtained from non amplified monolithic sensors, especially with the LFoundry LF15A 150 nm technology. The last iteration of MiniCactus, called MiniCactus V2, has been tested in beam in June-July 2024 at CERN. The best time resolution obtained so far is 60 ps on a 500 micron by 500 micron pixel, with a 175 micron thick sensor biased at -350 V. We will describe the limitations encountered in the testbeam, how they have been understood and overcome and how the performance of the front-end has been optimized to prepare the next test beam period, planned in July 2025 at CERN.
Since a possible path to improve on the time resolution of monolithic sensors is the addition of a buried PN junction, acting as a charge multiplicating layer, we will also show IV curves of such test structures that have been produced in LF15A technology. This characterization is a first step towards assessing the complete functionality and performance of this new type of sensor.
Speakers: Prof. Philippe Schwemling (Université Paris-Saclay (FR)), Yavuz Degerli (CEA Saclay) -
9
Monolithic strip sensorsSpeaker: Ingrid-Maria Gregor (DESY & Bonn University)
-
3
-
18:00
Drinks
-
1
-
-
WG/WP1 - CMOS technologies: WP1 project proposals
-
10
HV-CMOS Pixel Detector Demonstrator with Serial Powering and Innovative Interconnections
This Common Project proposal aims to develop a HV-CMOS multi-chip pixel detector demonstrator suitable for large scale production in future Higgs factory experiments, based on multi-chip modules with data aggregation and serial powering capabilities. These multi-chip modules, including low-mass multilayer flexible PCBs, will then be integrated in staves, where modules will be powered in serial mode utilising the on-chip Shunt Low Drop Out (SDLO) regulators. Together with data aggregation, this will substantially reduce the number of stave data and power connections. Low-mass aluminium flex productions, innovative connection methods (e.g. single-point Tape Automated Bonding), low-mass mechanical support, and efficient cooling technologies will be explored for overall system optimization in power and material budget. The expertise gained by the participating institutes will be beneficial for the integration of future large scale devices that will be developed by the strategic DRD3 projects in the next few years.
Speaker: Prof. Attilio Andreazza (Università degli Studi e INFN Milano (IT)) -
11
All-silicon ladder concept for CMOS monolithic pixel detectors
The All-Silicon project focuses on the development of monolithic CMOS pixel modules. Unlike traditional pixel detector modules, which involve individually diced chips from the wafer that are subsequently glued onto a support structure, the all-silicon approach integrates several CMOS chips into a single, uniform ladder, cut from a single silicon wafer. Each ladder is diced in one large self-
supporting piece, allowing for direct assembly in the detector. The all-silicon solution offers a more compact, lower-power, and cost-effective option for future high-luminosity particle physics experiments.To reduce material even further, a Redistribution Layer (RDL) is being developed to provide efficient power distribution for the module, eliminating the need for hybrid PCBs. In addition, thermal and mechanical simulations are employed to optimize the performance of the CMOS chips as well as the RDL, defining optimal air-cooling conditions to ensure effective heat dissipation to prevent overheating due to heat produced in the CMOS chips and in the RDL components.
The presentation will outline the all-silicon ladder concept, preliminary tests with a RDL on a resistive heater and first results of thermo-mechanical simulations.
Speaker: Nana Chychkalo (Georg August Universitaet Goettingen (DE)) -
12
Design and characterization of CASSIA monolithic pixel sensors with gain
The CASSIA (CMOS Active SenSor with Internal Amplification) project is focused on developing monolithic active pixel sensors (MAPS) with internal signal gain in a commercial CMOS technology. The advantages of this approach include a higher input signal enabling simplification of in-pixel electronics, an improved signal-to-noise ratio for radiation hardness, and superior timing resolution for future 4D tracking applications. Initial prototype sensors (CASSIA1) were fabricated to demonstrate the feasibility of implementing a gain layer in the Tower Semiconductor 180 nm CIS process. Current developments are focused on the design of a new sensor prototype (CASSIA2), which implements the sensor structures with gain alongside in-pixel electronics to operate the sensors either in low-gain (LGAD) or high-gain (SPAD) mode.
The presentation will give an overview of the latest measurement results on CASSIA1, including measurements of sensor response to DC and pulsed laser sources, as well as in-pixel gain scans of various sensor implementations. The talk will also describe the designs featured on the CASSIA2 prototype, including the in-pixel front-end amplifier used for LGAD-mode operation, several types of quenching circuits used for SPAD-mode operation, as well as a simple digital readout architecture used to obtain pixel address information from small-scale matrices.
Speakers: Ivan Berdalovic, Tomislav Suligoj (University of Zagreb - FER) -
10:30
Coffee/Tea break
-
13
Design of COFFEE3, a small prototype for 55nm HVCMOS validation
The HVCMOS technology is promising technology for tracking detectors at future experiments such as LHCb upgrade and Higgs factories, for its radiation hardness, fast charge collection and hence good spatial and timing resolution. Development of HVCMOS in smaller feature size will allow more functionailities in the same pixel area, and a reduced power consumption. We proposed a project to develop HVCMOS sensor prototypes using 55nm CMOS process based on initial validation of the process. This talk will report the latest submission of COFFEE3 chip, a small prototype with two different array readout aiming at full validation of the process. One of the pixel array readout architecture implements novel design for optimal timing precision fully exploiting the small feature size, while the other adopts a more conservative strategy less sensitive to current process limitation. The updated timeline of the project proposal will also be briefly covered.
Speaker: Dr Yang Zhou (Institute of High Energy Physics, CAS, Beijing, China) -
14
Towards an OpenSource DMAPS project proposal
Geopolitics suggest to consider technologies that Europe has full control of. One option to avoid sources that might potentially become unavailable is to focus on Open-Source chip design tools and processes that are hosted in Europe and provide OpenPDKs. While this has already been proven to work for fully digital workflows, there is still a lot of work to be done for mixed-signal chips in general and for DMAPS in particular.
I will present initial steps taken with the OpenPDK for the IHP SG13G2 130nm SiGe process and outline ideas for a DRD3 common project to evaluate the EDA tools and ultimately submit and test a DMAPS chip using a fully Open-Source toolchain to demonstrate the ability to create a monolithic pixel detector without proprietary software and NDAs using a foundry based in Europe.Speaker: Daniel Muenstermann (Lancaster University (GB))
-
10
-
WG3/WP3 - Extreme fluence and radiation damage characterization: WG3/WP3 Scientific results & Project Proposals
-
15
Novel energy-sensitive x-ray cameras, record fusion-plasmas, real-time monitoring and the need of radiation-hardened sensors
The WEST superconducting tokamak in France features a full tungsten environment and is equipped with actively cooled walls providing valuable input for future operation of nuclear fusion reactors. Versatile multi-energy soft and hard x-ray pinhole cameras have been developed, calibrated, deployed and operated for long-pulse plasmas at WEST. These innovative imaging diagnostic leverages a pixelated Si and CdTe x-ray detectors capable of independently adjusting the lower energy threshold for photon detection on each pixel. Central electron temperature values and plasma effective charge are derived by modeling the slope of continuum radiation, extracted from ratios of inverted radial emissivity profiles across multiple energy ranges, without relying on a-priori assumptions of plasma profiles, magnetic field reconstructions, high-density limitations, or shot-to-shot reproducibility. Recent breakthroughs include the temporal evolution measurement of central temperature in quasi non-inductive scenarios with a stationary central electron temperature of ~4.5 keV (> 50 million degrees ℃) for up to 22 minutes with a total injected energy of up to 2.6 GJ. In addition, real-time measurements and control-room plots of plasma temperature and plasma position (<1 cm) are now also a reality. These results - among others – force our community to bridge the gap between fusion science and technology and high-energy physics using detector technology already developed for high-luminosity experiments at CERN capable of withstanding neutron fluences up to 10^15-10^16 n/cm2/MeV, and even higher: Si3D, SiC, Diamond and wide bandgap materials like GaN and AlN presently being considered for measuring UV, SXR and HXR, as well as neutron fluxes and spectra.
Speaker: Luis Delgado-Aparicio -
16
Irradiation studies of ATLAS18 mini strip detectors with 23 GeV protons in IRRAD facility
Several irradiation campaigns using 23 GeV protons were conducted at the IRRAD facility at CERN, employing test structures from ATLAS1 wafers for the ATLAS ITk strip sensors. These campaigns aimed to study charge collection efficiency after irradiation. When irradiating with a narrow beam of high energy protons, various effects must be considered to accurately estimate the actual fluence and interpret detector performance. Secondary particles generated in interactions of the primary protons with material of the support structure, as well as geometrical effects due to shallow incidence angle, can significantly increase the actual fluence to which samples are exposed. These effects were also studied using Geant4 simulation, which showed good agreement with measurements.
Extensive studies of effects of annealing at 60C on CCE were also performed. For detectors irradiated with neutrons or low energy protons the collected charge exhibited a beneficial effect of short-term annealing which was followed by a decrease in charge collection efficiency at longer annealing times. After irradiation with 23 GeV protons to fluences above 1.2e15 n/cm2 the collected charge remained unchanged or even decreased significantly after the first few tens of minutes of annealing. Edge-TCT measurements indicated that this unusual annealing behaviour is related to the double-peak electric field profile in the detector. Mixed irradiation with 23 GeV protons and neutrons to fluences matching the expected in the upgraded ATLAS experiment confirmed that this unusual annealing effect will not impact the operation of the ITk strip detector.
The results of these studies will be presented in this contribution.Speaker: Igor Mandic (Jozef Stefan Institute (SI))
-
15
-
Lunch break
-
WG3/WP3 - Extreme fluence and radiation damage characterization: WG3/WP3 Scientific results & Project Proposals
-
17
Hunting the X-Defect
This contribution presents new insights into the elusive "X-defect", observed in Thermally Stimulated Current (TSC) measurements as a low-temperature shoulder to the BiOi defect in irradiated silicon diodes. Despite repeated observations, this defect has so far eluded assignment to a specific chemical structure.
A low-resistivity (10$\,\Omega$cm) p-type epitaxial silicon diode, irradiated with 5.5$\,$MeV electrons, was investigated. Simulations were employed to reproduce TSC spectra using defect parameters obtained from Deep-Level Transient Spectroscopy (DLTS), allowing comparison and validation across both methods.
Double-DLTS measurements revealed that the underlying field-enhanced emission mechanism of the X-defect is a phonon-assisted tunneling process. This identification supports the assignment of the X-defect to the di-vacancy in the donor charge state $\text{V}_2(0/+)$, providing a strong candidate for its chemical structure.Speaker: Niels Sorgenfrei (CERN / University of Freiburg (DE)) -
18
Variations of carrier lifetime in silicon under different reactor neutron irradiation regimes
Carrier recombination lifetime in semiconductor material is a key parameter influencing the performance of radiation detectors. This property is highly sensitive to the presence of radiation-induced defects, which act as recombination centres and significantly alter carrier lifetime. However, the nature and concentration of these defects can vary depending on the specific irradiation conditions, and differences may arise not only between distinct irradiation facilities but also within different regions of the same reactor or particle accelerator chamber.
In this study, the carrier recombination dynamics in high-resistivity p- and n-type silicon samples subjected to neutron irradiation at fluences exceeding 10¹⁷ cm⁻² were investigated. The samples were irradiated in the Ljubljana TRIGA reactor in different channels. Carrier lifetime measurements were performed by the contactless microwave probed photoconductivity transients technique and the pump-probe setup by employing femtosecond laser pulses. In this talk, carrier recombination characteristics in Si under different reactor neutron irradiation regimes will be considered.Speaker: Tomas Ceponis (Vilnius University) -
19
Characterization of electrically active defects in unirradiated epitaxial 4H-SiC p+-n diodes
Silicon carbide (SiC) is a wide band gap semiconductor with strong potential for use in next-generation sensors for high-luminosity colliders. Its intrinsic properties enable reliable operation at elevated temperatures and significantly reduce the need for active cooling systems. Moreover, SiC is typically fabricated using chemical vapor deposition, a versatile technique that ensures good control over doping levels and material homogeneity.
In this study, unirradiated SiC diodes (PAD architecture) were investigated using Deep Level Transient Spectroscopy (DLTS) to identify and characterize electrically active defects. DLTS measurements were conducted over a broad temperature range (80 K to 700 K), allowing the detection of multiple defect levels with distinct activation energies and capture cross-sections.
The identification and characterization of these defect states provide critical insights into the intrinsic defect landscape of unirradiated SiC PAD devices. These findings serve as an essential baseline for understanding defect evolution under irradiation and contribute to the optimization of SiC-based device design for high-radiation environments.Speaker: Cristina Besleaga Stan (National Inst. of Materials Physics (RO)) -
20
Radiation hardness and annealing studies of silicon diodes produced on 8-inch wafers for CMS HGCAL
To handle the tenfold increase in radiation from the High-Luminosity LHC, CMS will
replace its endcap calorimeters with the High-Granularity Calorimeter (HGCAL).
Silicon pad sensors, covering an area of 620 m2 in the electromagnetic and
high-radiation hadronic regions, must withstand fluences of up to 1e16 neq/cm2.
They are fabricated on 8-inch p-type wafers with thicknesses of 120, 200, and
300 μm. Each wafer also includes dedicated test structures for quality assurance and
radiation hardness evaluation.
These test structure diodes are currently used in four irradiation and annealing
campaigns, addressing and going beyond CMS HGCAL radiation hardness
qualification needs.
Neutron irradiation campaigns covering both a low fluence range from 1e13 to
2e14 neq/cm2 and a high fluences range from 2e15 to 1.5e16 neq/cm2 allow to
investigate a broad parameter space regarding radiation damage and annealing
behaviour at up to five different temperatures (6.5 °C to 60 °C).
To simulate a more realistic operational scenario, one set of diodes was irradiated to
fluences ranging from 5e14 to 4e15 neq/cm2 and subsequently annealed at three
different temperatures within the expected beneficial annealing window. In a second
step, these diodes will be further irradiated to end-of-lifetime fluences, consistent
with those studied in the high-fluence campaign.
Additionally, a subset of diodes was irradiated with protons (2e15–8e15 neq/cm2),
and long-term annealing studies at 20 °C , 40 °C and 60 °C were started in order to
specifically investigate potential differences in the annealing behaviour depending on
the impact particles.
This talk will present initial results from the low fluence, double irradiation, and proton
campaigns, covering observed beneficial annealing effects. Advanced results from
the high fluence campaign will be shown in a separate talk by Leena Diehl.Speaker: Marie Christin Muehlnikel (CERN) -
21
Temperature dependence of the annealing time constants of silicon produced on 8-inch wafers for CMS HGCAL
To face the higher levels of radiation due to the 10-fold increase in integrated luminosity during the High Luminosity LHC, the CMS detector will replace the current endcap calorimeters (CE) with the new High Granularity Calorimeter (HGCAL). It will facilitate the use of particle flow calorimetry with its unprecedented transverse and longitudinal readout and trigger segmentation, with more than 6M readout channels. The electromagnetic section as well as the high-radiation regions of the hadronic section of the HGCAL (fluences above $10^{14} n_{eq}/cm^2$) will be equipped with silicon pad sensors, covering a total area of $620 m^2$). Fluences up to 1.5e16 $n_{eq}/cm^2$ and doses up to 1.5 MGy are expected.
The sensors are processed on novel 8-inch p-type wafers with active thicknesses of 300$~\mu$m, 200$~\mu$m and 120$~\mu$m and cut into hexagonal shapes for optimal use of the wafer area and tiling. With each main sensor several small sized test structures are hosted on the wafers, used for quality assurance and radiation hardness tests. In order to investigate the radiation-induced bulk damage, the diode test structures of these sensors have been irradiated with neutrons at JSI (Jožef Stefan Institute, Ljubljana) to fluences between 2e15 $n_{eq}/cm^2$ and 1.5e16 $n_{eq}/cm^2$ .
In this talk, the electrical characterisation and charge collection measurements of the irradiated silicon diodes will be presented. The study focuses on the isothermal annealing behaviour of the bulk material at temperatures of 6.5°C, 20°C, 30°C, 40°C and 60°C in order to extract the temperature dependent annealing time constants that allow scaling to temperatures such as the 0°C foreseen as shutdown temperature of the CE.
Speaker: Leena Diehl (CERN) -
15:40
Coffee/Tea break
-
22
Application of van der Pauw Test Structure in Assessing Doping Removal in Silicon Detectors
Doping removal is a well-known consequence of radiation damage in silicon detectors and has likely become the primary effect since the introduction of Low-Gain Avalanche Diodes (LGADs). In standard n-in-p LGADs, acceptor removal degrades the timing performance after irradiation by decreasing the effective acceptor concentration in the gain implant. Furthermore, in next-generation LGADs—such as resistive LGADs and compensated LGADs—donor removal is also expected to be significant. In resistive LGADs, the resistive layer that enables high spatial resolution, even with large pixel sizes, is made by donor doping. In compensated LGADs, a valuable candidate for performing 4D tracking up to extreme fluence (above $10^{17}$ 1 MeV $n_{eq}/cm^2$), the gain implant is realised through a carefully balanced compensation of acceptor and donor doping. As a result, understanding and characterising doping removal is crucial.
In this contribution, we showcase how variations in sheet resistance due to irradiation, assessed through van der Pauw test structures, can be used to evaluate doping removal. Typically, these test structures consist of the layer under study implanted onto a substrate of the opposite conductivity type to reduce parasitic effects. However, we will demonstrate that through comparison with simulations, insightful information can also be gained from structures where the layer under investigation shares the same conductivity type as the substrate.
Speaker: Alessandro Fondacci (Università and INFN Perugia (IT)) -
23
TID Impact on IHEP-IME AC-LGAD Strip Sensors
With the development of collider experiments, the demand for detectors with high time and spatial resolution increased. AC-LGADs have been investigated widely due to their excellent time and spatial resolution. However, radiation exposure may damage the N++ layer, thereby affecting the performance of AC-LGADs. We conducted a TID irradiation test on a 5.6 mm AC-LGAD strip designed by IHEP and fabricated by IME, and studied the electrical characteristics such as IV and CV under high-dose TID irradiation. Additionally, we investigated changes in spatial and time resolution using laser TCT and beta tests to evaluate the lifespan and expected operational performance of this type of detector.
Speaker: Weiyi Sun (Chinese Academy of Sciences (CN)) -
24
Response of AC-LGADs to Ionizing and Non-ionizing Radiation Damage
Low gain avalanche detectors with DC- and AC-coupled readout were exposed to ionizing and non-ionizing radiation at levels relevant to future experiments in particle, nuclear, medical, and astrophysics. Damage-related change in their acceptor removal constants and inter-channel resistivity are reported.
Speaker: Dr Jiahe Si (University of New Mexico) -
25
Updates on the PAB activities and preliminary results
Updates on the ongoing activities of the Partial Activation of Boron (PAB) common project will be given. Preliminary results will be shown. The schedule of the PAB batches from CNM and FBK will be discussed.
Speaker: Valentina Sola (Universita e INFN Torino (IT)) -
26
Update on the "Defect engineering in PAD diodes mimicking the gain layer in LGADs" project
An update on the "Defect engineering in PAD diodes mimicking the gain layer in LGADs" project will be given.
Speaker: Dr Joern Schwandt (Hamburg University (DE)) -
27
DiscussionSpeakers: Ioana Pintilie (National Inst. of Materials Physics (RO)), Dr Joern Schwandt (Hamburg University (DE))
-
17
-
-
-
WG2/WP2 - Hybrid Silicon Technologies: Scientific Presentations
-
28
Introduction, news and plansSpeakers: Alessandro Tricoli (Brookhaven National Laboratory (US)), Anna Macchiolo (University of Zurich (CH)), Martin Van Beuzekom (Nikhef National institute for subatomic physics (NL))
-
29
Novel silicon 3D-trench pixel detector fabricated on the 8-inch wafer utilizing CMOS processing technologies
A novel 3D-Trench silicon pixel sensor featuring an enclosed deep trench surrounding the central columnar cathode will be developed in this project, the pixel size ranges from 25×25 μm2 to 150×150 μm2. The fabrication will be performed on the 8-inch CMOS pilot line at the Institute of Microelectronics of the Chinese Academy of Sciences (IMECAS). To reduce the dead area in the 3D sensor, the Bosch Deep Reactive Ion Etching (DRIE) technology is being developed to achieve an aspect ratio of more than 100:1. At least two batches of sensors will fabricated in this project, the first batch is expected to be delivered in 2026 and mainly used to validate the fabrication technology, the later batch will be delivered by 2027 and focused on the performance investigations targeting a position resolution of less than 10 μm, a time resolution of less than 50 ps and a radiation hardness of more than 1×1017 neq/cm2. Variations of this technology will also be developed in this project, for example double-sided 3D trench electrode detectors (DS-3DTED), back-incidence 3D composite electrode silicon detectors (3DCESD), hypothetical sphere-electrode detectors, novel 3D electrode LGAD.
Speaker: Manwen Liu (Chinese Academy of Sciences (CN)) -
30
Development of very small pitch, ultra rad- hard 3D sensors for tracking + timing applications at FBK
This project aims at developing the next generation of 3D pixel sensors, further progressing in the
trend of decreasing pixel size which started with the ATLAS IBL and continued with the ATLAS ITk
and CMS Inner Tracker 3D pixels. Target applications are the possible Phase-3 upgrades of ATLAS
and CMS and the upgrade of LHCb VELO (with timing). Inherent to the 3D pixel architecture is the
improvement in the radiation hardness as the interelectrode distance is decreased, which promises to
mantain the devices fully efficient up to irradiation fluences of 10 17 n eq cm -2 and beyond. Novel pixel
layouts with multiple column configurations are also expected to offer excellent time resolution,
comparable to the 3D-trench devices. Two production runs are foreseen at FBK with an optimized
single-sided technology allowing for a good fabrication yield also in case of large size pixel arrays.Speaker: Maurizio Boscardin (Fondazione Bruno Kessler (IT)) -
31
Presentation of the TI-LGAD projectSpeaker: Anna Macchiolo (University of Zurich (CH))
-
32
Development of Ultra-fast Time Low Mass Tracking DetectorsSpeaker: Alessandro Tricoli (Brookhaven National Laboratory (US))
-
33
LGAD based Timing Tracker Development for Future Electron ColliderSpeaker: Mei Zhao (Chinese Academy of Sciences (CN))
-
34
Investigation of Oxygen Contamination Impact on Acceptor Removal
Radiation tolerance of Low Gain Avalanche Detectors (LGADs) is one of the major challenges in the development of precise timing tracking detectors for future hadron collider experiments. A widely accepted hypothesis for accepter removal attributes the deactivation of implanted boron to the formation of boron-oxygen complexes, which introduce donor-like defect levels. To investigate the role of oxygen contamination, prototype sensors with varying concentration of oxygen were fabricated. In addition, the Partially Activated Boron (PAB) method — which aims to reduce oxygen-induced defects by cleaning oxygen with inactive boron — was applied to some samples. These prototypes were irradiated, and the accepter removal coefficients were evaluated and compared across different samples. In this talk, I will present the results from these new prototypes, with a focus on the correlation between oxygen contamination and accepter removal behavior.
Speaker: Koji Nakamura (KEK High Energy Accelerator Research Organization (JP)) -
10:25
Coffee Break
-
35
Performance of irradited TI-LGADs at 120 GeV SPS pion beams
Trench-isolated (TI) LGADs, developed at FBK, are pixelated LGAD implementations where pads are separated by physical trenches etched within the silicon substrate and filled with a dielectric. Developed as an alternative approach to implant-based inter-pad separation (JTEs), this technology promises a dramatic reduction to dead regions, mitigating fill factor issues inherent to small-pitch pixelated LGAD matrices. Through a dedicated 120 GeV SPS pion test beam campaign, the time resolution, efficiency and inter-pad distance of Carbon Infused irradiated TI-LGADs is presented in MIP conditions. Fluences up to 2.5 $\times$ 10 $n_{eq}/cm^2$ are evaluated, for single trench implementations with varied trench width. The combined timing and tracking readout used in this study, integrating ROI triggering, sub-μm multi-object alignment, multi-channel waveform digitization and achieving a 5-7 μm spatial resolution through a MIMOSA26 telescope, is also reviewed. Preliminary results are discussed for temperatures of $-25^{o}C$.
Speaker: Antonio Gomez Carrera (Universidad de Cantabria and CSIC (ES)) -
36
Picosecond timing using TI-LGADs on Timepix4
In recent years, development of pixel detectors has evolved from only improving the spatial resolution to also improving the temporal resolution.
The ultimate goal is to develop a 4 Dimensional tracking (4D tracking) system capable of combining micrometer spatial resolution with a temporal resolution in the order of tens of picoseconds. Sensor types such as Low-Gain-Avalanche-Detectors (LGADs) provide a promising avenue for detectors with excellent time resolution due to their intrinsic gain. Especially modifications to the process such as Trench-Isolated-LGADs (TI-LGADs) that allow for small pixel structures similar to those found in typical planar sensors are essential for achieving 4D tracking.
However, at the level of tens of picoseconds, both the ASIC and the Sensor contribution become equally important. Unlike single pixel measurements read out with an oscilloscope, a fully hybridized system with corresponding limitations provided by the ASIC has many important aspects that need to be understood and corrected for to achieve the best performance.
The Nikhef Detector R&D group has investigated the performance of variants of the TI-LGAD produced by FBK for RD50 with 55×55 pixels and a 55 micron pitch to a Timepix4 readout ASIC.
In this presentation we will present recent testbeam and lab results of these assemblies, focusing on the different contributions and corrections required to achieve the best time resolution with a fully hybridized system.Speaker: Uwe Kramer (Nikhef National institute for subatomic physics (NL)) -
37
Development of 3D-Trench Sensors in IMECAS
Silicon 3D Detector has demonstrated excellent performance, especially after high fluence irradiation, it has been running successfully on ATLAS Detector since 2015. In addition, it has also attracted investigations in other fields, astronomy, microdosimetry, medical imaging, etc. A novel 3D-Trench sensor has been designed and fabricated at the Institute of Microelectronics of the Chinese Academy of Sciences (IMECAS) using the 8 inch CMOS process technology. In the first batch, an ultra-narrow etch width of 0.5 µm and ultra-high depth-to-width ratio of 70:1 have been achieved. This talk will present its design, fabrication and the preliminary measurement results of Current-Voltage (IV), Capacitance-Voltage (CV), Charge Collection Efficiency (CCE) and Timing Performance before irradiation. In addition, another novel design of double-sided 3D trench electrode detector (DS-3DTED) structure will also be presented. The device’s electrical characterizations, including electrostatic potential and electric field distributions, I–V, C–V, full depletion voltage and transient current with x-ray incidence, are performed with TCAD tools. A 311 μm deep trench has been achieved through the Bosch process on the IMECAS. The maximum depth-to-width ratio is close to 105:1 when the trench width is 2 μm, which is an excellent foundation for manufacturing future 3D detector with a large fill factor and small dead region.
Speaker: Manwen Liu (Chinese Academy of Sciences (CN)) -
38
IV, CV and Fast Timing Measurement Results of the RD50 Common Project 3D Sensors
Sensors with fast timing capabilities are a critical component for all future tracking detectors to disentangle high multiplicity events. Silicon 3D sensors utilize columns etched orthogonal to the sensor substrate as their readout electrodes, in contrast to regular, planar, detector technologies, where the electrodes are only found on the sensor surface. 3D sensors display, in addition to their excellent time resolution, a high radiation tolerance, making them ideal candidates for use in HEP tracking detectors.
In the course of a common RD50 project, 3D sensors with two different column layouts, hexagonal and rectangular, and different column counts were designed and produced by CNM.
In this talk the IV and CV characteristics of these 3D sensors and initial fast timing measurement results for a small number of samples will be presented. Furthermore, a quick overview of the new amplifier boards designed in Freiburg will be given.
Speaker: Fabian Simon Lex (University of Freiburg (DE)) -
39
Double-Sided 3D Detectors at CNM: TCT Results and Measurement Plans
As part of the DRD3 project "Double-Sided 3D Detectors for Ultra-Radiation Hard Timing Applications," we present the designs and the initial timing characterization with TCT of double sided 3D sensors produced at IMB-CNM. We also outline the roadmap for upcoming studies, which include detailed electrical characterization and the selection of new devices for testing at the ELI Beamlines facility.
Speaker: Stefano Terzo (IFAE Barcelona (ES)) -
40
Progress on 2PA-TCT analysis and the first demonstration of 3PA-TCT on 3D Si Double Sided Double Column (CNM RD50) structures tuned for fast timing
This contribution has three distinguished parts all devoted to understanding the timing parameters of 3D Si CNM sensors and artefacts affecting the TPA -TCT measurements.
In contrast to planar detectors, 3D Si Double Sided Double Column devices were designed with n and p columns etched through the bulk, minimizing charge drift distance and improving timing. However, the peculiar geometry and electrode configuration of these sensors create non uniformities in both the internal electric field and the weighting field, resulting in a broader time-walk and compromising the sensor’s time resolution. The complex three-dimensional distribution of electrodes and sensitive detector volumes presents significant challenges for detailed microscopic characterization of charge transport properties, which is indispensable for architecture optimization. Here, we present the first study allowing for the generation of comprehensive 3D mappings of timing parameters across the 3D pixel sensors volume. The micrometer spatial resolution was obtained by using laser-based transient current technique (TCT) with two-photon absorption (TPA). Two prototypic detectors with alternative electrode configurations, quadratic and hexagonal, have been examined and compared. The spread of time of signal arrival (ToA) vs. bias and laser power at the different depths has been systematically evaluated, by illuminating device with fs-laser from the front side. The effect of amplifier was studied too.
In the second part of this contribution, we will show the results from our study where 3D Si device was illuminated by the fs-laser (TPA-TCT) from the back side with removed metalized part.
In the third part we will present our preliminary results on the 3D Si with the Three Photon Absorption-TCT technique. We expect this technique to be more suitable for irradiated 3D samples than 2PA since 1PA (Single Photon absorption) contributes to 2PA in irradiated samples and this contribution increases with increased fluency affecting the precision of measurements.
Speaker: Gordana Lastovicka-Medin (University of Montenegro (ME))
-
28
-
12:55
Group photo
-
Lunch break
-
WG2/WP2 - Hybrid Silicon Technologies: WP2 project proposals
-
41
Insights into the first production of DC-coupled Resistive Silicon Detectors
4D-tracking is a highly relevant topic in the development of future tracking detectors for high-energy physics experiments. Among the most promising sensor technologies for tracking in 4 dimensions are Resistive Silicon Detectors (RSD), based on Low Gain Avalanche Diode (LGAD) technology, that aim to achieve a timing resolution of approximately 30 ps and a spatial resolution of the order of a few percent of the pixel pitch. The effectiveness of resistive read-out for space reconstruction has been demonstrated with AC-coupled RSDs. Building on this, INFN and FBK proposed an improved version of this technology featuring DC-coupling (DC-RSD) between read-out channels and the resistive layer.
This contribution presents an overview of the first production of DC-RSDs fabricated by FBK within the framework of 4DSHARE project. The DC-RSD design aims to confine signal sharing within individual pixel through Trench Isolation (TI) technology. The batch was extensively characterized at wafer level and single devices have been characterized with laser TCT system and with real particles in beam tests at DESY. This contribution will present the key features of the DC-RSD design and the most recent results obtained on their spatial and temporal resolutions.
Speaker: Marco Ferrero (Universita e INFN Torino (IT)) -
42
Performance of first full-size production of AC-LGADs for the ePIC detector
Low Gain Avalanche Detectors (LGADs) are characterized by a fast rise time (~500ps) and extremely good time resolution (down to 17ps), and potential for a very high repetition rate with ~1 ns full charge collection. For the application of this technology to near future experiments such as e+e- Higgs factories (FCC-ee), the ePIC detector at the Electron-Ion Collider, or smaller experiments (e.g., the PIONEER experiment), the intrinsic low granularity of LGADs and the large power consumption of readout chips for precise timing is problematic. AC-coupled LGADs, where the readout metal is AC-coupled through an insulating oxide layer, could solve both issues at the same time thanks to the 100% fill factor and charge-sharing capabilities. Charge sharing between electrodes allows a hit position resolution well below the pitch/sqrt(12) of standard segmented detectors. At the same time, it relaxes the channel density and power consumption requirement of readout chips. Extensive characterization of AC-LGAD devices from the first full size (up to 3x4 cm) production from HPK for ePIC will be shown in this contribution. Eight wafers of strip sensors were produced and tested with both laser TCT and probe station (IV/CV). We will also present the first results on AC-LGADs irradiated with 1 MeV reactor neutrons at JSI/Ljubljana to fluences on the order of 1e13 to 1e15 n/cm2.
Speaker: Dr Simone Michele Mazza (University of California,Santa Cruz (US)) -
43
Environmental Stress Tests on (AC-coupled) Low Gain Avalanche Diodes
Low Gain Avalanche Diodes (LGADs) are a significant improvement upon standard silicon sensors because the gain layer provides timing resolution on the scale necessary to lend usage in environments such as the Large Hadron Collider (LHC) and accordingly form the backbone of timing layers present in the CMS and ATLAS phase 2 upgrades at the LHC. AC-coupled LGADs (AC-LGADs) allow charge sharing between electrodes to achieve improved spatial resolution per readout channel compared to standard LGADs, enabling a near-100% fill factor and providing micrometer-level spatial resolution.. The response of LGAD and AC-LGAD performance and electrical characteristics to environmental conditions such as temperature and humidity are vital to study as LGADs and AC-LGADs are to be operated in extreme environments such as the HL-LHC, FCC, fixed target experiments, and in outer space. LGADs and AC-LGADs fabricated at Brookhaven National Laboratory (BNL) are stress-tested at the BNL Silicon Laboratory, DRD3 laboratory at CERN, and Brown university by repeatedly cycling the temperature between -60C and 120C and applying a bias voltage until breakdown is observed. The data is analyzed to extract the breakdown voltage as a function of temperature. IV-scans are also performed at a wide range of humidities in order to examine any potential dependence.
Speaker: Trevor Russell (Brown University (US)) -
44
Studies on ML processing and compression of signal shared AC-LGADs
Resistive Silicon Devices (RSDs), particularly AC-coupled Low Gain Avalanche Diodes (AC-LGADs), open the path of pico second level space and time (4D) tracking in high-energy physics (HEP) experiments such as those at the Large Hadron Collider (LHC), Electron-Ion Collider (EIC), and future (lepton) colliders facilities. These sensors combine the fine spatial resolution of segmented detectors with the excellent timing performance of LGADs, achieving nearly 100% fill factor. Unlike conventional detectors, typically structured as linear strip arrays (1D) or pixel matrices (2D), RSDs offer a highly flexible geometry for readout pads, allowing for optimization based on experimental demands.
When ionizing radiation interacts with these sensors, the generated charge spreads beyond adjacent pixels. This broad charge sharing, while beneficial for interpolation-based resolution enhancement, is complicated by reduced signal amplitudes and Landau fluctuations on pixels farther from the true hit location. To address these challenges, we study pixelated AC-LGADs fabricated at Brookhaven National Laboratory with different pad geometries, including square and triangular configurations with a 500 μm × 500 μm pitch, and analyze their impact on spatial resolution.
In contrast to previous studies, we leverage full-waveform information from each readout channel and utilize Recurrent Neural Networks (RNNs) to infer the full waveforms of the readout pads, given the hit’s position and AC-LGAD structure, thereby reconstructing the hit position. The higher precision achieved by the classical charge-imbalance and geometry-based matrix inversion methods is leveraged by the amount of information processed by the networks, such as identifying optimal trade-offs between spatial granularity and data volume. Initial studies on Transient Current Techniques are used as inputs to further refine the algorithms with particle beams, where Landau fluctuations challenge the readout.
To support real-time applications and reduce computational load, we evaluate waveform rasterization techniques for compressing temporal signal data while preserving critical spatial information. These techniques are essential for future implementation on Field Programmable Gate Arrays (FPGAs) and other low-latency hardware platforms. Additionally, we conduct comparative studies of alternative geometric pad arrangements, assessing how shape and connectivity influence charge collection and algorithmic performance. These combined studies demonstrate the feasibility and scalability of using RSDs with flexible geometries, optimized readout configurations, and machine learning-enhanced reconstruction to meet the stringent resolution and speed requirements of next-generation high-energy physics (HEP) detectors.
Speakers: Gaetano Barone (Brown University), Jessica Tang (Brown University (US)) -
45
Performances of the hybrid of LGAD and LATIC
LGAD(Low Gain Avalanche Detector) is used in the HGTD(High Granularity Time Detector) of ATLAS phase II upgrade due to its excellent time resolution and spatial granularity. In order to utilize its high granularity advantage, it is necessary to bond the detector with a front-end readout chip of the same channel size using the flip chip process. The front-end readout chip is used to collect signals, amplify, discriminate, and measure the detector signals arrival time. The LGAD electronics team at the University of Science and Technology of China has developed a prototype chip called LATIC(LGAD Amplification and Timing IC) for LGAD readout. The prototype chip has a 5x5 structure and has completed electronic testing. It has been bonded with USTC IME sensor. The structure, electronic performance testing, flip chip bonding, and preliminary test results after flip chip bonding of LATIC will be introduced.
Speaker: Zhuang Li (University of Science and Technology of China (CN)) -
15:30
Coffee Break
-
46
Investigation of low-fluence proton and neutron irradiation on n-type LGADs
Low Gain Avalanche Detectors build on n-type substrate (nLGADs), developed by IMB-CNM, are optimized for the detection of low-penetrating particles such as soft X-rays, low-energy protons, and UV photons. Their design features a n-type gain layer that enables efficient charge multiplication for charge generation near the surface, making them suitable for applications in medicine, industry, and scientific research. Studying radiation effects on nLGADs not only provides insight into the fundamental physics of donor removal, gain suppression and hole amplification in the n-type gain layer, but also offers synergies with current HEP developments, including novel, radiation tolerant concepts such as the compensated LGAD.
In this study, we present the investigation of radiation-induced degradation in nLGADs irradiated with 60 MeV protons and reactor neutrons, up to maximum fluences of 1·10$^{14}$ particles/cm2. This extends our previous work on high-energy (23 GeV) proton irradiation to lower energies and different particle types. Electrical characterization including current-voltage (IV) and capacitance-voltage (CV) measurements are used to study changes in the effective doping concentration leading to space charge sign inversion (SCSI) and altered depletion behavior with irradiation. These effects were observed in nLGADs irradiated with 23 GeV protons already at fluences considerably lower than those commonly tested in the HEP sensor community, and are now investigated in more detail. Additionally, annealing studies are conducted to investigate the extent of reverse annealing effects after irradiation. Transient Current Technique (TCT) with different laser wavelengths is employed to probe gain degradation, gain suppression and donor removal, while Two-Photon Absorption TCT (TPA-TCT) is used to give insight into the evolution of electric fields in the nLGADs with irradiation.Speaker: Veronika Kraus (Vienna University of Technology (AT)) -
47
Technological developments and performance of n-type Low Gain Avalanche Detectors (nLGAD) at IMB-CNM
Low Gain Avalanche Detectors built on high resistivity n-type substrates (nLGAD) have emerged as a suitable alternative to conventional p-type sensors for low penetrating radiation detection. The Radiation Detectors Group of the IMB-CNM has been exploring the potentialities of this technology since 2020, mainly working within the framework of the CERN’s RD50 collaboration and several national and international projects.
This contribution aims at summarizing the progress of the nLGAD technology in the IMB-CNM facilities, with an emphasis on the latest experimental results, as well as the technological challenges and the envisioned future developments and applications.Speaker: Pablo Fernandez-Martinez (IMB-CNM, CSIC) -
48
Evaluation of LGAD Performance Degradation due to TID Aging Under 10 keV X-ray Irradiation
One of the greatest milestones in scientific infrastructure in Brazil is concentrated in Sirius, installed at the Brazilian Center for Research in Energy and Materials (CNPEM), in Campinas. Just like the European Synchrotron Radiation Facility (ESRF), located in Grenoble, France, Sirius represents one of the most advanced fourth-generation synchrotron light sources in the world.
Both Sirius and ESRF operate with ultra-high brightness X-ray beams, being essential for experiments that investigate in detail the structures and properties of materials on various scales [1].
Currently, Sirius has multiple beamlines. It is an electron storage ring designed to operate at an energy of 3 GeV and beam current of up to 350 mA, with an ultra-low natural emittance of 0.28 nm·rad. The spectral brightness of Sirius for X-rays can reach values above 10²¹ photons/s/mm²/mrad²/0.1%BW, placing it among the brightest light sources in the world. The beamlines cover a wide spectral range, from infrared to hard X-rays, with maximum photon energies around 30 to 40 keV [1]. Each beamline is dedicated to different experimental techniques, enabling cutting-edge research in areas such as nanotechnology, biosciences, applied physics, among others. It is a strategic resource for scientific and technological development in Brazil.
To enable experiments on the Sirius beamlines, detectors that are robust to X-ray radiation are required, with low time resolution, high pixel density, and good efficiency across a wide energy range [1], [2].
Considering these requirements, studies are being conducted using the LGAD device, which meets the demands imposed on the beamlines, using the LGAD 3.2 HPK model developed in Japan and exposed to an X-ray source. The tests provided significant results related to the TID (Total Ionizing Dose) effect, which causes surface damage to the device.
Based on the analyses carried out, a TID-specific testing methodology for detectors was developed. An X-ray source with an effective energy of 10 keV was used to investigate the effects of aging and charge generation at the interfaces. This energy ensures high efficiency in the generation of electron-hole pairs through the photoelectric effect, providing data to estimate the robustness of detectors in harsh environments such as synchrotron accelerators [3].
In this context, irradiation tests were followed by detailed electrical characterization focused on essential parameters for LGAD performance. Among the tests performed, the forward and reverse current versus voltage (I × V) curves and capacitance versus voltage (C × V) measurements were highlighted, enabling a detailed assessment of the detector’s behavior when exposed to radiation.
To assess the effectiveness of LGAD detectors under ionizing radiation, electrical characterizations were carried out at different stages of the experiment, before, during, and after irradiation. These initial analyses indicated progressive degradation in the device's electrical parameters, prompting a more in-depth investigation of the effects caused by X-ray exposure [3].
The characterization and irradiation stages were carried out, respectively, at the Nanoelectronics and Integrated Circuits Laboratory and the Laboratory of the Effects of Ionizing Radiation (LERI), both located on the campus of Centro Universitário FEI, in Brazil. This integrated infrastructure enabled strict control of experimental conditions and the acquisition of relevant results.
Considering the specific irradiation conditions adopted, the results revealed significant changes in the device's electrical characteristics, especially in the I × V curves, which showed a reduction in conduction voltage and degradation in the avalanche region. It was also observed that, between irradiation steps, a slight recovery of electrical properties was achieved through Room Temperature Annealing (R.T.A.) processes. However, from the 91 krad(Si) dose onward, the degradation became irreversible, leading to the loss of the charge multiplication capability, an essential feature of LGADs, and causing the device to behave like a PIN diode, compromising its originais function in detecting high-energy particles.
As a continuation of this work, future steps intend to expand the analysis through the application of a more detailed comparative methodology using X-rays, involving different variants of LGAD detectors. The proposal follows the line of investigation evidenced in reference [4].REFERENCES
[1] Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Projeto Sirius: A nova fonte de luz síncrotron brasileira, Campinas, SP, Brasil, 2014. [Online]. Available: https://lnls.cnpem.br/wp-content/uploads/2016/08/Livro-do-Projeto-Sirius-2014.pdf.
[2] M. Moll, “Displacement Damage in Silicon Detectors for High Energy Physics”, IEEE Trans. Nucl. Sci., vol. 65, no 8, p. 1561–1582, ago. 2018, doi: 10.1109/TNS.2018.2819506.
[3] T. A. Silva et al., “Analysis of Low Gain Avalanche Detector (LGAD) Response to 10 keV X-Rays”, in Proc. SEMINATEC 2025 (XIX Workshop on Semiconductors and Micro and Nano Technology), to be published.
[4] A. Doblas et al., “Inverse LGAD (iLGAD) Periphery Optimization for Surface Damage Irradiation”, Sensors, vol. 23, no 7, p. 3450, mar. 2023, doi: 10.3390/s23073450.Speaker: Thalia Alves da Silva (Centro Universitário FEI) -
49
Active Edge Silicon Sensors Fabricated with Side Implants
Silicon detectors with reduced inactive regions around their periphery are desirable for applications in high-energy physics, X-ray experiments, and medical imaging. Typically, an insensitive area is required to accommodate guard rings, which help maintain the electric field distribution around peripheral pixels and isolate defects at the physical edges of the detectors that could otherwise generate high leakage currents.
A solution to reduce or eliminate this dead area is the use of active-edge or 3D technology [1,2]. However, implementing active edges presents significant challenges in sensor fabrication and is ideally performed after all other processing steps. This is generally not feasible with conventional methods due to the high-temperature annealing required after doping the guard rings or active-edge structures [3,4]. Additionally, sensors with thicknesses of 500 µm or even 1 mm are desirable for broader spectrum X-ray energy detection, but etching through substrates thicker than 300 µm is extremely difficult and costly.
Microwave annealing offers a promising alternative to traditional high-temperature annealing, as it can be applied after fabrication is complete. In this process, dopants are activated while the bulk temperature remains below 500 °C [5–7]. This study explores a new method of achieving active-edge detectors, in which the device edges are implanted after all other processing steps and subsequently annealed at low temperature using microwave annealing. This approach enables the fabrication of active edges in thicker substrates while also reducing overall manufacturing costs. Preliminary results of current versus bias voltage measurements on both n-in-p and p-in-n devices, before and after implantation and annealing, will be discussed.[1] S. Parker et al., “A proposed new architecture for solid-state radiation detectors,” NIM (A) Volume 395, Issue 3 August 1997, p.328-343.
[2] C. J. Kenney et al., “Results from 3D silicon sensors with wall electrodes: near-cell-edge sensitivity measurements as a preview of active-edge sensors,” IEEE Trans. on Nucl. Sci, Vol. 48, No.6, Dec 2001.
[3] S. Eranen et al., “3D processing on 6 inch high resistive SOI wafers: fabrication of edgeless strip and pixel detectors,” NIM (A) Vol. 607, Issue 1, 1 August 2009, p.85-88.
[4] O. Koybasi et al., “Edgeless silicon sensors fabricated without support wafer,” NIM (A) Vol 953, 11 Feb 2020 163176.
[5] A. T. Y. Cheng, et al., “A Low-Temperature Microwave Anneal Process for Boron Doped Ultrathin Ge Epilayer on Si Substrate,” IEEE Electron Device Letters, Vol. 30, Feb 2009.
[6] Y-L. Lu, et al., “Nanoscale p-MOS Thin-Film Transistor with TiN Gate Electrode Fabricated by Low Temperature Microwave Dopant Activation,” IEEE Electron Device Letters, Vol 31, May 2010.
[7] J. Segal, et al., “Low-temperature Junction Formation for Thinned High Energy Physics Sensors,” 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference Proceedings (NSS/MIC), 2018.Speaker: Andrew Donald Gentry (University of New Mexico (US))
-
41
-
50
Status of collaborationSpeaker: Gregor Kramberger (Jozef Stefan Institute (SI))
-
DRD3 collaboration board meeting: https://indico.cern.ch/event/1551957/ Nikhef - Veltman center (3rd floor)
Nikhef - Veltman center (3rd floor)
Veltman centre, 3rd floorhttps://indico.cern.ch/event/1551957/
-
-
-
WG2/WP2 - Hybrid Silicon Technologies
-
51
Timing Measurements for 3D and LGAD Sensors Using ⁹⁰Sr
To evaluate the timing performance of the 3D detector, we developed a readout system for silicon detectors, taking inspiration from the Gali-66+ used by the Energy Frontier group in Japan. To better understand the working principle of a transimpedance amplifier (TIA) based on BJT transistors, we also referred to a TIA design developed by UCSC using a BFP840ESD (SiGe) transistor.
In this study, we used a ⁹⁰Sr source to generate signals in both 3D and AC-LGAD detectors. We first present the timing resolution results for the 3D and AC-LGAD detectors. Then, based on the basic amplification principle of the TIA, V=IR, we varied the resistance R to investigate its impact on the pulse maximum, rise time, and RMSD. These characteristics were analyzed for the BFP840ESD (SiGe)-based design and compared with the Gali-66+.
If you have any suggestions or questions, please let me know — any feedback is very welcome.Speaker: chuan liao (The High Energy Accelerator Research Organization) -
52
Status and future developments of Low Gain Avalanche Detector technologies at IMB-CNM
IMB-CNM has been a main actor in the development of Low Gain Avalanche Detectors since the initial device conception, more than a decade ago. In the last years, our efforts have been centred on developing new LGAD designs to enhance the device performance in aspects such as the charge collection efficiency or the improvement of the fill factor. At the same time, our technologies are being revisited to refine the fabrication yield, in particular for large pixelated array devices.
This contribution presents our latest advances and challenges in technologies such as trench-isolated inverse LGAD (TiLGAD), a promising design that looks for a 100% fill factor, for a wide range of low and high penetrating particles. In addition, we will show the first characterization of our deep-junction LGAD devices, a crucial step to stabilize the performance of the IMB-CNM pixel technologies.Speaker: Pablo Fernandez-Martinez (IMB-CNM, CSIC)
-
51
-
WG8 - Dissemination & outreach: Status
-
WG4 - Simulations
-
53
Simulation and design of IHEP AC-LGAD for timing tracker detector
The AC-LGAD, functioning as a 4D detector, is capable of simultaneously delivering both timing and spatial information. Additionally, the strip AC-LGAD offers the advantage of reducing the number of readout channels while maintaining position resolution along the bending direction. This makes it an excellent candidate for timing tracker detectors in future colliders. However, the length of the strips in AC-LGADs significantly impacts their performance, particularly in terms of sensor capacitance, timing resolution, and power consumption of readout ASIC.
To evaluate these effects, simulations of AC-LGADs with varying structural and process parameters are conducted. These simulations focus on analyzing three key capacitances: bulk capacitance, capacitance between strips, and coupling capacitance. These capacitances play a crucial role in determining the overall performance of the sensors. The study also explores methods to minimize bulk capacitance and inter-strip capacitance.
In the latest submission from IHEP, AC-LGAD designs featuring strip lengths of 1 cm, 2 cm, and 4 cm, along with DC-LGAD, will be presented. Furthermore, adjustments to process parameters will be implemented to achieve improved spatial resolution, ensuring the detectors meet the requirements of future collider experiments.Speaker: Mei Zhao (Chinese Academy of Sciences (CN)) -
54
Simulation of irradiated hybrid pixels modules at fluences expected at HL-LHC
Signal loss is the main limitation on tracking/vertexing performance due to radiation damage effect to hybrid pixel detectors when irradiated at fluences expected at High Luminosity LHC (HL-LHC).
It is important to have reliable predictions on the charge collection efficiency (CCE) performance after irradiation in order to predict operational voltage values and test tracking algorithms robustness.
In this talk I will present the validation of combined TCAD and Allpix2 simulations of hybrid silicon pixels sensors. In particular I will test different trapping models to identify the one giving the best predictions.
Eventually I will present predictions on the CCE performance of pixels modules at HL-LHC.
Speaker: Marco Bomben (APC & Université Paris Cité, Paris (FR)) -
55
RASER - A python package for solid-state radiation detector simulation
The Python-based simulation package RASER (RAdiation SEmiconductoR) has been developed to advance semiconductor radiation detector research through integrated device-circuit simulation. The toolkit enables simulation-driven exploration of novel detector concepts through three core modeling dimensions: semiconductor material properties (including wide-bandgap compounds), customizable electrode geometries (from planar to 3D architectures), and radiation-matter interaction processes (covering charged particles to laser excitation). This multi-physics approach generates quantitative predictions for detector performance and characterization results. By integrating Technology Computer-Aided Design (TCAD) device physics simulations with SPICE circuit modeling, RASER permits comprehensive evaluation of detector systems across implementation paradigms, including discrete front-end electronics and integrated circuit solutions.
Speaker: Chenxi Fu (Chinese Academy of Sciences (CN)) -
10:30
Coffee break
-
56
Research on Performance and Applications of SiC on RASER
RASER is a self-developed semiconductor simulation software. It can simulate semiconductor devices of silicon and silicon carbide in planar and 3D structures, obtaining key parameters. Recently, it has been optimized. It successfully simulated important electrical properties of SiC LGAD, verifying the gain layer model. The simulation of the deep-level compensation model of SiC detectors after proton irradiation validated the irradiation model. It also achieved simplified simulation of SiC strip detectors and estimated their resolution. In detector application simulation, it was used for the design and simulation of SiC detectors in CEPC and CSNS luminosity detection, providing data for performance evaluation and design optimization.
Speaker: Suyu Xiao (Shandong Institute of Advanced Technology, China) -
57
Allpix Squared 3.2 - Closing the Gap to IC Design
Allpix Squared is a core infrastructure of DRD3 and provides a versatile open-source simulation framework for semiconductor detectors to the community. This contribution summarizes the improvements implemented over the past year and provides an overview of the features available in the most recent release version 3.2.
A special focus is given to the work concerning the closer integration of integrated circuit design tools, and the storage of realistic pulses as netlists for processing in SPICE simulators such as Cadence Spectre is described. In addition, an outlook is provided on the data exchange interface between Allpix Squared and the PixESL virtual prototyping framework.
Speaker: Simon Spannagel (Deutsches Elektronen-Synchrotron (DE)) -
58
Simulations of Monolithic Active Pixel Sensors for the OCTOPUS Project
The OCTOPUS (Optimized CMOS Technology for Precision in Ultra-thin Silicon) project, part of the DRD3 collaboration, aims to simulate, develop, and characterise fine-pitch monolithic sensors using the 65 nm TPSCo CMOS process. The project targets a spatial resolution of 3 µm, a temporal resolution below 5 ns, a material budget of 50 µm of silicon equivalent, and an average power consumption below 50 mW/cm² to meet the requirements of vertex detectors in future lepton colliders experiments.
OCTOPUS places significant emphasis on the extensive simulation effort, which aims to improve sensor layouts. This includes simulations of standard process sensor designs with different readout options and moderate pitches of ~20 µm, and n-gap designs with smaller pitch. Building on past studies of n-blanket and n-gap designs, current research also explores ways to improve deep n-implant geometry.
The sensor simulation strategy combines TCAD static simulations and high-statistics Monte Carlo simulations, both of which are essential for guiding sensor design and performance optimization.
Based on simulation results and previous studies of sensors produced with the same technology, the expected hit rate in the vertex detector of future lepton colliders was assessed, showing that they are in line with OCTOPUS performance goals.
This contribution presents simulation results for sensors with various pixel pitch configurations, including both standard and n-gap layouts.
Speaker: Gianpiero Vignola -
59
Simulation of narrow column 3D detectors – search for gain
Simulation of narrow column 3D detectors – search for gain
The 3D detectors with narrow and highly doped columns are most likely candidates for 3D devices with gain, similar to array of solid-state proportional wire tubes. 3D detectors with junction electrodes – n+ columns of <=1 um width could lead to gain depending on the width of the doping profile. Some initial performance simulation of such devices was performed identifying key design elements when single sided processing is used. The tip of the junction electrode is the area of peak field and is the reason for non-homogenous gain across the device. This leads to implications to timing performance of the devices the gain however allows the use of thinner devices for the same collected charge making detectors with smaller capacitance possible. Such detector would also benefit from smaller clusters, better efficiency hence extending the radiation tolerance beyond present designs. The simulations result of timing and charge collection efficiency will be presented.Speaker: Gregor Kramberger (Jozef Stefan Institute (SI)) -
60
Simulation of MAPS with uniform amplification factor
The development of monolithic CMOS silicon sensors with gain layers is actively being developed worldwide. In many gain-layer-equipped Monolithic Active Pixel Sensors (MAPS), the gain layer is implemented only in a limited region within each pixel, resulting in restricted charge multiplication areas. We are working toward the development of a new type of MAPS that features a gain layer covering the entire pixel area—similar to the concept of AC-LGADs—in order to achieve a uniform gain within each pixel. We will report on the results of TCAD simulations and the current status of sensor prototyping.
Speaker: Yuta Okazaki (KEK High Energy Accelerator Research Organization (JP)) -
61
WG4 - Updates and DiscussionSpeakers: Håkan Wennlöf (Nikhef National institute for subatomic physics (NL)), Marco Mandurrino (Universita e INFN Torino (IT))
-
53
-
Lunch break
-
WG6/WP3 - Non-silicon-based detectors: Scientific Presentations
-
62
Sapphire detector characterization with α-source and e-beam
Artificial sapphire has gained interest as a wide bandgap ($9.9\;{\rm eV}$) material for radiation hard detectors. Optical-grade single crystal sapphire is industrially grown in a variety of sizes with low cost. The low signal yield ($22\;\text{eh}\,{\rm μm}^{-1}{\rm MIP}^{-1}$) makes it suitable for applications where the collected charge is well above the readout noise. Also, it exhibits very low leakage current at room temperature ($\sim \rm pA$), which remains nearly unchanged even after exposure to high doses, keeping shot noise levels minimal.
A R&D campaign aimed at developing a microstrip sapphire detector was carried out within the scientific context of LUXE at DESY. Sapphire pad and strip detectors ($110\;{\rm μm}$ and $150\;{\rm μm}$ thick) were manufactured and characterized with x-ray, electron beam and alpha source – the last both at room and cryogenic temperature. Various electrode compositions were fabricated and investigated.
The study presents experimental results on charge collection efficiency as a function of bias voltage, as well as measurements of ionization yield and radiation tolerance.
Speaker: Dr Pietro Grutta (University of Padua, INFN) -
63
Gallium Nitride Schottky Devices for Sensing Applications
Gallium nitride (GaN) is a desirable material for charged particle spectroscopy in high temperature, high radiation environments. We report on results obtained from GaN vertical Schottky devices fabricated on 8 µm thick non-intentionally doped GaN epitaxial layers grown on native GaN substrates where the thick epi-layer is intended for ionizing radiation detection. Bulk dark current densities of 2 µA/cm$^2$ at -1 V with perimeter leakage attributed to surface effects of 4.5 nA/cm at room temperature, with an extracted Schottky barrier of 0.72 eV for a Ni/Au Schottky metal. The capacitance-voltage data reveal background doping in the low 10$^{15}$ cm$^{-3}$ range. Pulsed 355 nm UV light produces a photoresponse that increases as a function of reverse bias, with an estimated carrier collection efficiency of up to 5%. Moving the incident beam away from the Schottky contact reveals a minority carrier diffusion length up to 10 µm. However, due to the strong absorption of GaN at this wavelength, this lateral diffusion length is impacted by surface effects which conceals the bulk diffusion length. Finally, optical deep-level transient spectroscopy reveals two electron trap states at 456 and 129 meV below the conduction band with low concentrations (<1% of the doping) and capture cross-sections <10$^{-15}$ cm$^{-2}$.
Speaker: Christoph Thomas Klein (Carleton University (CA)) -
64
Radiation effects in 4H-SiC PN diodes, LGAD sensors, and MOSFET transistors
The wide bandgap 4H-SiC semiconductor material exhibits several intrinsic properties - namely, excellent radiation hardness, thermal stability, and high breakdown voltage - that make it a promising candidate for deployment in high-radiation environments. Recent advances in its industrial-scale production have further enhanced its attractiveness for high-energy physics applications.
This contribution presents an overview of the development and characterization of 4H-SiC-based sensors produced by the onsemi company based in the Czech Republic. The study includes the evaluation of 4H-SiC PN diodes and Low Gain Avalanche Detectors (LGADs) featuring an internal charge multiplication layer. Electrical characterization covers the dependence of reverse leakage current and bulk capacitance on the applied depletion voltage, internal gain measurements using UV light sources, and the first Transient Current Technique (TCT) studies employing UV lasers.
Radiation tolerance was assessed through irradiation of both PN and LGAD samples with 24 GeV protons at the CERN IRRAD facility, reaching fluences up to $1 .0\times10^{16} \mathrm{p/cm^{2}}$. Additional insight into radiation-induced effects was gained by subjecting the biased 4H-SiC MOSFET transistors to gamma irradiation using a $^{60}$Co source at UJP Praha a.s. and to 24 GeV proton irradiation at CERN IRRAD. The obtained results provide new perspectives on the radiation hardness of 4H-SiC devices and underscore their potential for future use in demanding environments typical for next-generation high-energy physics experiments.
Speakers: Jiri Kroll (Czech Academy of Sciences (CZ)), Radek Novotny (Czech Technical University in Prague (CZ))
-
62
-
WG6/WP3 - Non-silicon-based detectors: Scientific Presentations and WP3 project proposals
-
65
Silicon Carbide Source Characterisation Setup and Results at CERN
Silicon carbide (SiC) is a promising material for particle detection and beam diagnostics due to its wide bandgap. At CERN, we established an experimental setup with radioactive sources to evaluate the performance of SiC sensors. This effort involved integrating SiC PAD sensors from 2nd to 4th CNM wafers being tested into a small, shielded tabletop setup, enabling precise measurement of pulse characteristics such as timing resolution and charge estimation. The initial results underscore significant advancements in the overall measurement setup, including enhanced signal stability and improved shielding. We will show the outcomes of the calibration procedures and the initial data acquisition runs performed using the UCSC board with several sensors. These measurements provide a first validation of the system’s capability to resolve fast signals and support further development of SiC-based detector technologies.
Speaker: Roman Mueller (CERN) -
66
Characterization of 4H-SiC p-n Junction Detectors for Alpha Particle Detection in Plasma Diagnostics
In future nuclear fusion reactors, monitoring escaping suprathermal ions, such as the 3.5 MeV alpha particles produced in D-T reactions, is crucial for optimizing plasma performance and maintaining reactor integrity. Silicon carbide (SiC) emerges as a promising candidate for fast ion detection due to its wide bandgap, high radiation tolerance, and thermal stability.
This study focuses on a 4H-SiC p-n junction detector developed by the Institute of Microelectronics of Barcelona (IMB-CNM). The detector has a ring collector electrode instead of a metalized surface, making it suitable not only for charged particle detection but also as a potential diagnostic tool for X-ray detection in fusion environments.
The detector was irradiated with 3.5 MeV alpha particles at fluences ranging from 10^11 to 10^13 ions/cm^2 under three different temperature conditions: room temperature (RT), 200°C, and 400°C. The irradiation process was monitored in real time using Proton-Induced X-ray Emission (PIXE) to ensure accurate fluence control. The spectroscopic response was evaluated through Charge Collection Efficiency (CCE) measurements using Ion Beam Induced Charge (IBIC).
These results provide valuable insight into the suitability of SiC-based detectors for use in extreme environments, such as nuclear fusion reactors, where high temperatures and radiation levels challenge conventional diagnostic systems.Speaker: Carmen Torres Munoz (Universidad de Sevilla (ES)) -
67
Fabrication Progress and Performance Characterization of SiC detectors
Wide bandgap (WBG) semiconductors are increasingly strengthening their dominance in the power device market, with significant improvements in crystal growth and device processing technologies. As the core material for high-voltage power devices, silicon carbide (SiC) has emerged as a highly competitive candidate for particle detectors, owing to its outstanding radiation hardness (maintaining ultra-low leakage current post-irradiation) and wide temperature-range operation capability (from room temperature to elevated temperatures). We have fabricated first-generation 4H-SiC PIN and low-gain avalanche detector (LGAD) devices, and conducted characterization of their performance under 80 MeV proton irradiation (2×1011~1×10¹⁴ nₑq/cm²) and high-temperature operation (90°C). Based on these results, we have developed optimized second-generation devices, with PIN detectors currently in the fabrication process. For AC-LGAD pixel devices, we have established a preliminary TCAD simulation framework to guide optimization of critical process parameters, demonstrating viable approaches for radiation-resistant SiC detector development.
Speaker: Xiyuan Zhang (Chinese Academy of Sciences (CN)) -
15:50
Coffee break
-
68
Development of innovative SiC detectors for harsh environments
This talk will review the development of innovative radiation detectors that can be robustly operated in harsh environments. It requires the use of advanced microelectronic technology together with nanotechnology, and therefore, outcomes include the definition of completely new processing sequences. This new approach considers exploring novel uses and functionalities of 2D materials, such as the use of graphene in electrical contacts or alternative detection principles and signal management.
In this talk, I will present the preliminary results of the electrical and charge collection studies of SiC detectors fabricated at Centro Nacional de Microelectrónica (CNM-CSIC) in Spain and irradiated with different particles and iones.Speaker: Dr Giulio Pellegrini (Centro Nacional de Microelectrónica (IMB-CNM-CSIC) (ES)) -
69
In-situ Radiation Damage Study of Silicon Carbide Detectors subjected to Clinical Proton Beams
4H-silicon carbide (4H-SiC) is an emerging wide bandgap detector material in high-energy physics due to its superior temperature stability and low dark current compared to silicon detectors. Critical to the performance of SiC detectors and electronics is their response to radiation damage induced defects. There exists a significant amount of literature showing the compensation of lightly doped intrinsic layers and the loss of forward conduction after neutron irradiation to fluences of around $5\times10^{14}\: \text{n}_{\text{eq.}}/\text{cm}^2$.
However, only little data exist on these processes in detail, as most studies aim at higher irradiation fluences, where these processes have already taken course.We present results from an irradiation study focusing on lower irradiation fluences between $10^{10}-10^{14}$ $\text{p}^{+}/\text{cm}^2$, using an in-situ measurement method which allows for the characterization of the same sample at different fluences throughout the irradiation. Three different SiC PiN detector samples have been irradiated and measured at the MedAustron ion therapy center. The detector samples all have an active area of $3\times 3\: \text{mm}^2$ and were picked from two different wafers with different active thicknesses and doping concentrations. Proton beams with an energy of $252\:\text{MeV}$ were used with clinical beam intensities of $\sim 10^{10} \:\text{p}^{+}\text{/spill}$ and a spill length of 1$\:$s.
Current-voltage (I-V) and capacitance-voltage (C-V) characteristics were measured several times during the irradiation, as well as charge collection efficiency (CCE) before and after the irradiation.Compared to more traditional irradiation campaigns where multiple samples are irradiated to different fluences, these measurements allowed for a characterization of different radiation damage levels within the same samples.
These results provide a unique perspective on the gradual manifestation of radiation damage induced effects in SiC detectors and present an opportunity to develop and further enhance radiation damage models.
Additionally, this study gives an insight to the expected lifetime of SiC detectors in medical applications.Speaker: Daniel Radmanovac (Austrian Academy of Sciences (AT)) -
70
Mechanisms of proton irradiation-induced defects on the electrical performance of 4H-SiC PIN detectors
Silicon Carbide (SiC) demonstrates significant potential for high-energy particle detection in complex radiation environments due to its exceptional radiation resistance, high thermal conductivity, and fast response. 4H-SiC PINs fabricated by Nanjing University were irradiated by 80-MeV protons to investigate the irradiation effects. The irradiated PINs showed a decrease in leakage current and lost typical capacitance-voltage characteristics. The deep levels and minority carrier lifetime were measured by DLTS and TRPL. A Deep-Level Compensation Model (DLCM) was established using open source software RASER to simulate I-V and C-V characteristics under proton irradiation up to $7.8\times10^{14} n_{eq}/cm^2$. Simulation result shows the electric field changed due to compensation effect after irradiation, and caused the decrease of leakage current.
Speaker: Zaiyi Li (Chinese Academy of Sciences (CN)) -
71
Rising Time and Charge Collection Efficiency of Graphene-Optimized 4H-SiC PIN Detector
Silicon carbide detectors exhibit good detection performance and are being considered for detection applications. However, the presence of surface electrode of detector limits the application of low-penetration particle detectors and photodetectors. A graphene-optimized 4H-SiC detector has been fabricated to expand the application of SiC detectors. Its electrical properties and the charge collection performance of α particles are reported. The effective doping concentration of lightly doped 4H-SiC epitaxial layer is about 4.5 × 1013cm-3, approaching the limit of the lowest doping level by the SiC epitaxial growth technique. The rising time of the graphene-optimized ring electrode detector is reduced by 24% at 200 V, compared to ring electrode detector. The charge collection efficiency (CCE) of graphene optimized 4H-SiC PIN is 99.22%. When the irradiation dose is 2× 1011 neq/cm2, the irradiation has a small impact on the rising time and uniformity of the rising time for the graphene-optimized 4H-SiC detectors. This study proves that graphene has a certain radiation resistance. Graphene-optimized 4H-SiC detectors can not only reduce the signal rise time, but also improve uniformity of signal rise time and stability of charge collection. This research will expand the application of detectors in fields such as X-ray, low energy ions, UV light detection, particle physics, medical dosimetry, the transient current technique (TCT) measurements, heavy-ion detection and nuclear reactor detection.
Speaker: Congcong Wang (Chinese Academy of Sciences (CN)) -
72
Study of 4H-SiC LGADs for 4D-Tracking Application
This report presents the latest progress in the development of 4H-SiC LGADs by LBNL, NCSU, and BNL. Building on the successful fabrication of 4H-SiC LGADs with etched termination and field plate, we have developed 4H-SiC AC-LGADs with 4D-tracking capabilities. Preliminary evaluations of their timing and spatial resolution have been conducted using UV-TCT, β sources, and electron beams, demonstrating the promising potential of 4H-SiC LGADs for 4D-tracking applications.
Speaker: Tao Yang -
73
2.5 GeV Proton Irradiated 4H-SiC LGADs
In contrast to silicon, 4H-SiC offers the potential to exhibit superior radiation hardness and significantly lower leakage current making it a compelling candidate for LGAD technology in extreme environments. This reduced leakage current can eliminate the need for active cooling, offering important operational and engineering advantages in space- and power-constrained detector systems. A joint collaboration between NCSU, LBNL, and BNL has previously demonstrated functional 4H-SiC LGADs and evaluated their timing performance. This study represents ongoing progress from the collaboration, presenting an initial investigation of 4H-SiC LGAD performance following irradiation with 2.5 GeV protons at various fluences. Preliminary electrical characterization results are discussed, along with the next steps toward the realization of a radiation-hard LGAD platform based on 4H-SiC.
Speaker: Yashas Satapathy -
74
Project Proposal disussion and approvalSpeakers: Alexander Oh (The University of Manchester (GB)), Dr Tao Yang (Lawrence Berkeley National Laboratory), Xin Shi (Chinese Academy of Sciences (CN))
-
65
-
75
Social Dinner at Tolhuistuin Zonzij (Tolhuistuin)
Zonzij
Tolhuistuin
Arrival from 19:00 to 19:30
Dinner starts 19:30
-
-
-
WG5 - Characterization techniques, facilities
-
76
Introduction and newsSpeakers: Bojan Hiti (Jozef Stefan Institute (SI)), Prof. Ivan Vila Alvarez (Instituto de Física de Cantabria (CSIC-UC))
-
77
Advancements and future expansions of the Caribou DAQ system
Caribou is a versatile data acquisition system used in multiple collaborative frameworks (CERN EP R&D, DRD3, AIDAinnova, Tangerine) for laboratory and test-beam qualification of novel silicon pixel detector prototypes. The system is built around a common hardware, firmware and software stack shared across different projects, thereby drastically reducing the development effort and cost. It consists of a custom Control and Readout (CaR) board and a commercial AMD Zynq System-on-Chip (SoC) platform. The SoC runs a Yocto distribution integrating the custom software framework (Peary) and custom FPGA firmware built within a common firmware infrastructure (Boreal). The CaR board provides a hardware environment providing various resources such as power supplies, slow control interfaces, and high-speed data links for the target detector prototype. Boreal and Peary, in turn, offer firmware and software environments that enable seamless integration of control and readout for new detector prototypes. Additionally, a unified testing method, integrated into the above frameworks that supports the FPGA device families in use, is currently under development. While the first version of the system used a SoC platform based on the ZC706 evaluation board, migration to Zynq UltraScale+ platforms is progressing with the finalized support of the ZCU102 board and the ultimate objective of integrating the SoC functionality directly into the CaR board, eliminating the need for separate evaluation boards. This talk describes the Caribou system, focusing on the latest project developments and showcasing progress and future plans across its hardware, firmware, and software components.
Speaker: Ilias Kamoisis (CERN and Aristotle University of Thessaloniki (GR)) -
78
Running Your Test Beam with Constellation
The qualification of new detectors in test beam environments presents a challenging setting that requires stable operation of diverse devices, often employing multiple data acquisition (DAQ) systems running on several machines in a local network. Changes to these setups are frequent, such as using different reference detectors depending on the facility. Managing this complexity necessitates a system capable of controlling the data taking, monitoring the experimental setup, facilitating seamless configuration, and easy integration of new devices.
Constellation is a flexible control and data acquisition framework developed with the requirements of laboratory and test beam environments in mind. Besides the possibilities for control and monitoring of the setup, Constellation also offers data transmission over the network, which is useful for embedded DAQ systems such as Caribou.
This contribution will present an overview of Constellation and detail its deployment in a typical test beam situation.
Speaker: Stephan Lachnit (Deutsches Elektronen-Synchrotron (DE)) -
79
High Bandwidth Readout Electronics for TCT in Thin Detectors
The transient current technique (TCT) has been a workhorse of detector characterization, allowing for the extraction of drift velocities, electric fields, space charge densities, and more. However, for very thin detectors ($\leq 50$ μm), the currently available readout electronics start to run into bandwidth limitations, as the charge carrier drift time becomes of the same order of magnitude as the rise time of the readout electronics. This poses a challenge for wide bandgap materials such as silicon carbide, as the detector thickness that can be depleted is typically limited to 100 μm or less. However, at the same time, there is a high demand in TCT studies as several material properties, such as the mobility, are not as precisely known as they are for silicon.
We present ongoing work by HEPHY and SCIPP on readout electronics with very high bandwidths exceeding 5 GHz. Different approaches and the impact of the detector capacitance, bond wires, and other parasitics are discussed.
At HEPHY, a readout based on a commercial low-noise amplifier has reached rise times as low as 58 ps. With this readout setup, we conducted measurements on SiC diodes using alpha particles, a UV laser, and proton beams, for which we analyzed the resulting transient current signals to extract information about the charge carrier drift velocity. Comparisons with SPICE simulations highlight the impact of parasitics, particularly bond wire inductance. Finally, we outline upcoming studies, including TPA-TCT, where SCIPP is aiming to characterize SiC PIN sensors.Speaker: Andreas Gsponer (Austrian Academy of Sciences (AT)) -
80
Double Beam TCT (DB-TCT): new laser method for high rate sensor tests
4d tracking detectors for future experiments based on Resistive Silicon Detector technology will be exposed to high channel occupancy due to targeted low density of readout channels. To study the detector response to two nearly concurrent hits, we developed a new Transient Current Technique method (Double Beam TCT), where two focused pulsed laser beams can be controlled independently in space and time to imitate particle pile-up in the sensor. Spatial separation can be achieved by splitting a source beam into two beams coupled to two separate focusing optics systems, while the relative time delay between both pulses is controlled on a few ns level by a variable fiber length.
In the first part of the talk the optical, mechanical and DAQ components of the setup will be presented together with the basic data analysis. The first application of DB-TCT was implemented for characterization of a prototype AC-LGAD strip sensor produced by IME in a pilot run of the DRD3 Project: LGAD based timing tracker development for future colliders. Very preliminary results will be presented in the second part of the talk.
Speaker: Bojan Hiti (Jozef Stefan Institute (SI)) -
81
Discussion
-
76
-
10:30
coffee break
-
WG7/WP7 - Interconnect technologies
-
82
IntroductionSpeakers: Dominik Dannheim (CERN), Fabian Huegging (University of Bonn (DE)), Giovanni Calderini (LPNHE-Paris, Centre National de la Recherche Scientifique (FR))
-
83
In-house plating updates
As part of the CERN EP R&D programme and the AIDAinnova collaboration, innovative and scalable concepts for hybridisation and module integration are being developed for pixel detector applications in future colliders. Most interconnect processes require specific surface properties and topologies of the bonding pads. An in-house Electroless Nickel Gold (ENIG) plating process is therefore under development that can be performed at the single-die level and adapted to a wide range of pad geometries and bonding techniques. ENIG bumping is a promising solution for the next generation of hybrid detector assemblies due to the combination of chemical selectivity, reproducibility, and compatibility with existing packaging technologies. This contribution introduces the developed plating process and presents examples of the bumping results achieved for interconnect test devices, functional sensors and ASIC samples, alongside measurements of their height and uniformity.
Speaker: Moritz Lauser (KIT - Karlsruhe Institute of Technology (DE)) -
84
In-house Flip-Chip Hybridisation Updates
The development of hybrid pixel detectors requires a reliable and cost-effective interconnect technology, especially one that enables the hybridisation of single dies, offering greater flexibility for R&D and low-volume production. This presentation highlights the current status and recent advancements of in-house hybridisation processes developed within the CERN EP R&D programme and the AIDAinnova collaboration. These include bonding with Anisotropic Conductive Adhesives (ACA) as well as gold-stud bonding with epoxy underfill. The ACA approach replaces conventional solder bumps with conductive micro-particles embedded in an epoxy layer, applied either as a film or a paste, and enables electro-mechanical connection via thermo-compression using a flip-chip bonder.
Speaker: Dr Ahmet Lale -
85
Towards Ultra-Lightweight and Flexible Pixel Modules - First Prototype and Performance Results
To reduce the material budget and maximize the active area of sensors for future experiments, a 30 µm thick lightweight flex has been developed. The fabrication technology, combined with novel interconnection techniques, enables compact packaging through the direct attachment of chip connection pads to the flex. In addition to interconnection methods such as Anisotropic Conductive Films and gold studs, the successful integration and bonding of nanowires is demonstrated using advanced principles like sintering and glue-assisted bonding. This contribution introduces the module concepts and presents the initial electrical and mechanical results from demonstrator modules. Furthermore, the principles and preliminary results are shown, demonstrating how the current fabrication technology can be extended to address ASIC yield and increase the packaging density of the assembly.
Speaker: Julian Weick (CERN) -
86
MAPS Integration with Flexible and Low-Material-Budget Electronics
This work presents a novel approach for the packaging of ALPIDE/ALTAI chips that unlocks compact and non-planar assemblies with a minimal material budget. This solution represents an advancement based on methodologies developed for the ALICE ITS1 and the STAR tracker two decades ago. The core of this approach involves the use of flexible cables composed of aluminum and polyimide, with thicknesses on the order of tens of micrometers. These cables are connected to the sensors using single-point Tape Automated Bonding (spTAB), which replaces the traditional wire bonding technique that is suboptimal for curved integrations. The spTAB bonding is achieved by creating openings in the polyimide layer, allowing aluminum wires to remain free-standing, which are then connected to the sensor using pressure and ultrasonic energy. Extending this concept, we have applied this approach to entire printed circuit boards (PCBs), resulting in a fully flexible packaging solution maintaining an ultra-low material budget. This work introduces a prototype utilizing this method to bond a 50 µm-thinned ALPIDE chip, proposing it as a viable option for future designs necessitating flexible packaging for both the chip and associated electronics. The overall workflow, comprising microfabrication and assembly, is carried out in the Fondazione Bruno Kessler laboratories and will be presented to show the applicability of our solution for future experimental setups. The proposed packaging features a flexible PCB constructed from three stacked layers. These layers include a ground layer, a signal layer (encompassing both digital and analog signals), and a bonding layer (which substitutes wire bonding). The spTAB technique is employed for inter-layer connections within the PCB and for sensor bonding.
Speaker: David Novel -
87
Development of ultra-thin hybrid pixel detectors using Wafer-to-Wafer bonding
Wafer to wafer bonding offers an economic approach to interconnect all readout electronic chips with the solid-state sensor chips on the wafer by only one bonding step. This is a promising technology for the fabrication of 3D integrated ultra-thin hybrid modules for particle detection and timing layers in future particle detectors. The technology described in this contribution combines the metal-metal interconnection of pixels by Cu-Sn pillar bumps and the wafer level bonding by a photo-patterned polymer layer. In comparison to the metal-oxide-hybrid bonding process established in the industry for high volume production the metal-polymer hybrid wafer to wafer bonding process is applicable for wafers with higher surface topography tolerances. This project using TimePix3 wafers together with a passive sensor wafer built with LFoundry 150 nm technology to proof the concept is now in its last stages. The project will be introduced and latest results from the bonding process development with daisy chain wafers as well as from fabricated sensor wafers are presented.
Speaker: Fabian Huegging (University of Bonn (DE)) -
88
Discussion
-
82
-
Closeout
-
