Wide band gap semiconductors, such as GaN and SiC, have exhibited notable advantages, when they are applied as a nuclear radiation detector in a harsh environment of high temperature or strong radiation field. Recently a GaN alpha-particle detector of p-i-n structure was fabricated on a sapphire substrate in this article. The intrinsic layer of the detector was isoelectronic Al-doped GaN with...
SiC as a typical wide bandgap semiconductor material has the potential to be used in the high energy field thanks to its good performance under radiation environment as well as running without cooling compared with traditional Si devices. Followed by the previous study of the timing performance of the 4H-SiC PIN device, a first 4H-SiC LGAD has been fabricated by Nanjing University (NJU) China....
The Non Ionizing Energy Loss (NIEL) concept is used to compare and scale the damage impacted on semiconductor devices in different radiation fields. A particular weakness of the present NIEL concept consists in the inability to predict the different formation rates of cluster and point defects in the silicon (Si) crystal for different particles and particle energies. NIEL gives only the total...
We report on results of the irradiation bulk damage study in gamma irradiated standard float zone p-type silicon diodes. The study includes three types of diodes with different resistivities by CNM, HPK and IFX manufactures. The diodes were irradiated by Cobalt-60 gamma source up to 3.66 MGy in approximate charged particle equilibrium and then annealed for 80 minutes at 60°C. Electrical...
This project focuses on the investigation of trap energy levels introduced by radiation damage in epitaxial p-type silicon. Using 6-inch wafers of various boron doping concentrations (1e13, 1e14, 1e15, 1e16, and 1e17 cm-3) with a 50µm epitaxial layer, multiple iterations of test structures consisting of Schottky and pn-junction diodes of different sizes and flavours are being fabricated at RAL...
In this work the Thermally Stimulated Techniques including TS-Current (TSC) and TS-Capacitance (TS-Cap) has been used to study the properties of the radiation induced BiOi defect complex by 6 MeV electrons. Two different types of diodes manufactured on p-types epitaxial-(EPI) and czochralski-CZ silicon with a resistivity of about 10 Wcm were irradiated with fluence values in the range between...
Charge collection in Si p+-n-n+ detectors was studied in the in situ irradiation test at 1.9 K with intense 23 GeV proton beam fragmented in 400 ms spills in view of detector application as beam loss monitors in the LHC at CERN. The current pulse responses demonstrated a two-stage process of charge collection, in which, in the first stage, the current was induced by holes, and in the second,...
Gordana Lastovicka-Medin1, Mateusz Rebarz2, Gregor Kramberger3, Jakob Andreasson2 Tomas Lastovicka4, Jiri Kroll4, Kamil Kropielnicki2
1University of Montenegro
2Extreme Light Infrastructure
3Jozef Stefan Institute
4Czech Academy of Sciences
Different active thickness of LGADs and probing the sensitive depth from front and backside are exploited, The sensors used in this study...
Gordana Lastovicka-Medin1 , Milko Jaksic2 , Gregor Kramberger3 , Mauricio Rodriguez Ramos2 , Andreo Crnjac2 , Milos Manojlovic1
1 University of Montenegro,
2 Rudjer Boskovic Institute,
3 Jozef Stefan Institute
This work in progress is three folded. Firstly, gain anomalous behavior was studied in a such way that ion beams (C, He, Li, H+) and their energies were chosen so that Bragg...
Degradation of semiconductor detectors when exposed to high radiation rates leads to the necessity of development of tools and methods for characterization of these devices. One of these methods is the Two-Photon Absorption – Transient Current Technique (TPA-TCT) which provides spatially-resolved inspection of semiconductor detectors. This technique exploits the simultaneous absorption of two...
The Two Photon Absorption – Transient Current Technique (TPA-TCT) uses fs-pulsed infrared lasers, with photon energies below the silicon band gap. Excess charge carriers are generated mainly in a small volume (approximately 1µm × 1µm × 20µm) around the focal point of the laser beam, enabling resolution in all three spatial directions. Following the initial success of the method, a compact...
We present the commissioning measurements of the new fiber femto-laser at IFCA equipped with a fully integrated optical bench for microfocusing, signal stability monitoring and focus imaging. Compensation of the TPA-TCT signal fluctuations using the second harmonic generated with a BBO crystal will be described
TCT was used to study the effect of ionization density on gain in different non-irradiated LGADs. A simple model was used to explain the screening and was verified by measurements.
Existing impact ionisation models and parameters for silicon do not accurately describe the behaviour seen in LGAD sensors, so new impact ionisation parameters specifically applicable to LGADs was determined using simulations and timing measurements of sensors from various producers. The resulting model and parameters will be presented.
In this contribution, I will discuss two possible evolutions of the LGAD design.
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DC-RSD: up to now, resistive read-out in silicon detectors has been used only in AC-coupled detectors, the so-called AC-RSD or AC-LGAD. I will present here the first attempt to apply resistive read-out to a DC-coupled sensor.
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LGAD with bias ring: recent beam tests results showed that LGADs suffer...
The High Granularity Timing Detector (HGTD) project of ATLAS will reduce the pile-up effect in HL-LHC by providing precise time measurement of tracks. The Low- Gain Avalanche Detector (LGAD) with time resolution better than 35(70) ps before(after) irradiation is the key technology which has been studied by many institutes. The Institute of High Energy Physics Chinese Academy of Science (IHEP)...
Motivated by the need for fast timing detectors to withstand up to 2 MGy of ionizing dose at the High Luminosity Large Hadron Collider, prototype low gain avalanche detectors (LGADs) have been fabricated in single pad configuration, 2x2 arrays, and related PIN diodes, and exposed to Co-60 sources for study. Devices were fabricated with a range of dopant layer concentrations and, for the...
In this contribution, we will present measurements on
neutron-irradiated LGADs corresponding to our 6-inch, 50µm active
layer thick, epitaxial wafers run (6LG3). Samples were fabricated
using three boron implantation doses, and one energy, for the gain
layer definition. Gain, collected charge, acceptor removal constant
and timing measurements were carried out on these LGADs...
The fast rising signal of LGADs with high signal-to-noise ratio is key to achieve an excellent charge collection and time resolution for Minimum Ionizing Particles (MIPs). The LGAD technology will be used for the HL-LHC in the upgrade of both ATLAS and CMS timing detectors.
A full characterization of CNM LGADs on Si-Si and low resistivity epitaxial wafers irradiated up to 1e16 neq/cm2 will be...
Trench-Isolated LGAD (TI-LGAD) is a novel LGAD design where the standard inter-pixel isolating structure has been replaced with a trench, physically etched in the silicon and filled with a dielectric material.
The "RD50 TI-LGAD" project aimed at exploiting this new technology for the production of pixelated detectors with pixel and strip pitches down to 50 µm.
In the project framework, FBK...
We present a characterization of the novel Trench-Isolated LGAD (TI-LGAD) technology using a scanning TCT setup. The studied devices belong to the first production of pixelated TI-LGADs at FBK done in the framework of the RD50 collaboration. The TI-LGAD is a variation of the Low-Gain Avalanche Detector (LGAD) in which the segmentation of the detector in pixels is done by etching physical...
The Flavor physics program is one of the important topics for future lepton collider projects. In order to explore the full potential of the flavor physics program, a time-of-flight detector is needed to perform particle identification at an energy range from 1GeV to 5GeV.
We propose a time-of-flight detector based on AC-coupled LGAD technology, which has high timing resolution and spatial...
AC-coupled LGADs, also referred to as resistive silicon detectors (RSDs), rely on a design in which the multiplication layer and n$^{+}$ contact are continuous, and only the metal layer is patterned. In AC-LGADs, the signal is capacitively coupled from the continuous, resistive n$^{+}$ layer over a dielectric to the metal electrodes. The spatial resolution is not only influenced by the...
In this contribution, we present a new development of radiation-resistant silicon sensors. This innovative sensor design exploits the recently observed saturation of radiation damage effects on silicon, together with the usage of thin substrates, intrinsically less affected by radiation. The internal multiplication of the charge carriers will be used to overcome the small signals coming from...
The development of detectors that provide high resolution in four dimensions has attracted wide-spread interest in the scientific community for several applications in high-energy physics, nuclear physics, medical imaging, mass spectroscopy as well as quantum information. The Low-Gain Avalanche Diode (LGAD) silicon technology has already shown excellent timing performances, but since fine...
We present measurements of AC-LGADs performed at Fermilab’s test beam facility using 120 GeV protons. We studied the performance of various strip and pixel sensors that were produced by BNL and HPK. The measurements are performed with our upgraded test beam setup that utilizes a high precision telescope tracker, and a simultaneous readout of up 6 channels per sensor, which allows detailed...
Achieving granularity below the 1 mm scale (100 um or less) while maintaining high efficiency, precise timing, and good spatial resolution is a goal of continued R&D on silicon diode Low Gain Avalanche Detectors (LGADs). One approach, proposed by the SCIPP ultrafast sensor R&D group, is to make use of the diode junction to create avalanche-generating fields within the sensor, and then to bury...
The AC-LGAD technology has been shown to be a very promising technology within HEP due to it's extremely good time resolution and 100% fill factor. This technology is proposed to be used with the Timepix4 ASIC for imaging applications using soft X-rays. The fabrication of these devices is underway. Simulation studies have been performed to optimize the technology for a 55um pixel pitch and a...
In this work the properties of 200 $\mu m$ thick highly pixelated LGAD sensors bonded to a Timepix3 readout ASIC were characterised for the first time. Recent advances in the control of the LGAD fabrication process by Micron Semiconductor Ltd has allowed the manufacture of highly segmented devices where each pixel has an internal gain. Devices with 55 $\mu m$ pixel with 5 $\mu m$ Junction...
Where we present the characterization of the HVCMOS MPW2 chip pixel matrix using the ion microprobe station at the RBI 1 MV Tandetron accelerator with protons at 2 MeV. The proton beam spot (most probable area of impact) was around 30 um2, small enough to scan pixel by pixel the whole pixel matrix and with energy low enough to avoid SEE effects.
In high energy physics, the silicon pixel sensors manufactured in commercial CMOS chip fabrication lines have been proven to have a good radiation hardness and spatial resolution. Along with the mature manufacturing techniques and the potential of large throughput provided by the foundries, the so called "passive CMOS" sensor has become an interesting alternative to standard planer...
Passive CMOS pixel sensors are investigated in the context of the CMS Phase2 Tracker Upgrade. A prototype production of RD53A compatible pixel sensors was recently completed at LFoundry in 150nm CMOS process. This presentation will focus on the characterization of irradiated and non-irradiated pixel modules, composed by a CMOS passive sensor interconnected to a RD53A chip. The sensors are...
The new ATLAS Inner Tracker (ITk) sub-detector is necessitated by the impending High Luminosity Large Hadron Collider (HL-LHC) upgrade. This replacement is part of the phase-II upgrade programme for the HL-LHC which will see a sevenfold increase in peak instantaneous luminosity with a total ionizing dose of 53 MRad. The fully solid state ITk will employ silicon n+-in-p microstrip sensors in...
We report on the measurements of time resolution for double-sided 3D pixel sensors with a single cell of 50 $\mu$m $\times$ 50 $\mu$m and thickness of 285 $\mu$m, fabricated at IMB-CNM and irradiated with reactor neutrons from 8e14 MeV n$_{eq}$/cm$^2$ to 1.0e16 MeV n$_{eq}$/cm$^2$.
Measurements were conducted using a radioactive source at a temperature of $-$20 and 20 \textdegree C in a bias...
The next generation of inner tracking detectors will require spatial resolution down to 10um, radiation hardness above 10e16Neq/cm^2 together with a temporal resolution in the order to tens of pico seconds.
To face these challenges and overcome limitations of today's technologies, an alternative approach to internal gain through the use of a radiation sensitive doping layer is investigated...
In this presentation the relation between the leakage current and full depletion voltage to TID will be shown. From the measured I-V and C-V characteristics it is obvious that the dependence of the leakage current with respect to the TID is increasing linearly. On the other hand, the full depletion voltage and thus also the effective doping concentration shows a decreasing trend with higher...
The proton irradiation site at Bonn University has been introduced at previous RD50 workshops. Recently, the setup has been upgraded to minimize fluence fluctuations on the DUT and enable flexible irradiation procedures. The Bonn Isochronous Cyclotron delivers 14 MeV (~12.5 MeV on-device) protons with typical beam currents of 1 𝜇A and beam diameters of a few millimeters to the setup. Enhanced...
The CMS detector will be upgraded to face a 10-fold increase in integrated luminosity for the High-Luminosity LHC era. Its endcap calorimeters will be replaced by the high-granularity calorimeter (HGCAL). With its unprecedented transverse and longitudinal readout/trigger segmentation, with more than 6M readout channels, HGCAL will facilitate the use of particle-flow calorimetry. Silicon pad...
We revisit the radiation hardness of Carbonated CNM LGAD detectors (50 active thickness, run 10478) irradiated with PS protons up to 10$^{15}$ $n_{eq}/cm^{2}$. The study comprises electrical characterization of the gain layer doping removal, charge collection and timing with radioactive source.
