Fluence Dependence of Charge Collection of irradiated Pixel Sensors
T. Rohe, D. Bortoletto, V. Chiochia, L. M. Cremaldi, S. Cucciarelli, A. Dorokhov, C. Hoermann, D. Kim, M. Konecki, D. Kotlinski, K. Prokofiev, C. Regenfus, D. A… 展开作者
T. Rohe, D. Bortoletto, V. Chiochia, L. M. Cremaldi, S. Cucciarelli, A. Dorokhov, C. Hoermann, D. Kim, M. Konecki, D. Kotlinski, K. Prokofiev, C. Regenfus, D. A. Sanders, S. Son, T. Speer, M. Swartz
备注：
11 Pages, Presented at the 5th Int. Conf. on Radiation Effects on Semiconductor Materials Detectors and Devices, October 10-13, 2004 in Florence, Italy, v3: more typos corrected, minor changes required by the referee
The barrel region of the CMS pixel detector will be equipped with ``n-in-n'' type silicon sensors. They are processed on DOFZ material, use the moderated p-spray technique and feature a bias grid. The latter leads to a small fraction of the pixel area to be less sensitive to particles. In order to quantify this inefficiency prototype pixel sensors irradiated to particle fluences between $4.7\times 10^{13}$ and $2.6\times 10^{15} \Neq$ have been bump bonded to un-irradiated readout chips and tested using high energy pions at the H2 beam line of the CERN SPS. The readout chip allows a non zero suppressed analogue readout and is therefore well suited to measure the charge collection properties of the sensors.
In this paper we discuss the fluence dependence of the collected signal and the particle detection efficiency. Further the position dependence of the efficiency is investigated.
In this paper, we report on the study of the optical properties of YAG:Ce and GGG:Ce garnet crystals after irradiation in a 660~MeV proton beam with a fluence up to 8.9$\times$10$^{14}$ protons/cm$^2$. We found that the transparency of both crystals fell by no more than 7\% in the region of their own luminescence. The light yield of a YAG:Ce sample, measured one year after irradiation, dropped by about 35\%.
Silicon photomultipliers (SiPM) are solid state light detectors with sensitivity to single photons. Their use in high energy physics experiments, and in particular in ring imaging Cherenkov (RICH) detectors, is hindered by their poor tolerance to radiation. At room temperature the large increase in dark count rate makes single photon detection practically impossible already at 10$^{11}$ cm$^{-2}$ 1-MeV-equivalent neutron fluence. The neutron fluences foreseen by many subdetectors to be operated at the high luminosity LHC range up to 10$^{14}$ cm$^{-2}$ 1-MeV-equivalent. In this paper we presen…
The value of the scaling parameter $E_{\text{eff}}$ of the temperature dependence for current generated in silicon bulk is investigated for highly irradiated devices. Measurements of devices irradiated to fluences above $1 \times 10^{15} n_{\text{eq}} \text{cm}^{-2} $ have shown a different temperature scaling behaviour than devices irradiated to lower fluences. This paper presents the determination of the parameter $E_{\text{eff}}$ for diodes irradiated with protons up to fluences of $3 \times 10^{15} n_{\text{eq}} \text{cm}^{-2}$ in the bias range from $0$V to $1000$V at temperatures from $-…
Stable Charge Collection and Sub-45 ps Time Resolution in a 4H-SiC PIN Detector Irradiated With Low Fluence 16.5 MeV/u Ta Ions
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Qufu Normal University（曲阜师范大学）；State Key Laboratory of Particle Detection and Electronics（粒子探测与电子学国家重点实验室）；Liaoning University（辽宁大学）
The replacement of the existing endcap calorimeter in the Compact Muon Solenoid (CMS) detector for the high-luminosity LHC (HL-LHC), scheduled for 2027, will be a high granularity calorimeter. It will provide detailed position, energy, and timing information on electromagnetic and hadronic showers in the immense pileup of the HL-LHC. The High Granularity Calorimeter (HGCAL) will use 120-, 200-, and 300-$μ\textrm{m}$ thick silicon (Si) pad sensors as the main active material and will sustain 1-MeV neutron equivalent fluences up to about $10^{16}~\textrm{n}_\textrm{eq}\textrm{cm}^{-2}$. In order…
Characterization of Thin Pixel Sensor Modules Interconnected with SLID Technology Irradiated to a Fluence of 2$\cdot 10^{15}$\,n$_{\mathrm{eq}}$/cm$^2$
Eight production quality PbWO4 crystals of CMS have been irradiated in a 20 GeV/c proton beam up to fluences of 5.4E13cm-2. The damage recovery in these crystals has been followed for over a year. Comparative irradiations with 60Co photons have been performed on seven other crystals using a dose rate of 1 kGy/h. In proton irradiated crystals the light transmission band-edge shifts and the induced absorption length is proportional to the inverse of the 4th power of the wavelength. In gamma-irradiated crystals the band-edge does not shift but formation of absorption bands is seen clearly. The ab…
The absorption length, $λ_{abs}$, of light with wavelengths between 0.95 and 1.30$~μ$m in silicon irradiated with 24$~$GeV/c protons to 1$~$MeV neutron equivalent fluences between 0 and $8.6 \times 10^{15}~$cm$^{-2}$ has been measured. It is found that $λ_{abs}$ decreases with fluence due to radiation-induced defects. A phenomenological parametrisation of the radiation-induced change of $λ_{abs}$ as a function of wavelength and neutron equivalent fluence at room temperature is given. The observation of the decrease of $λ_{abs}$ with irradiation is confirmed by edge-TCT measurements on irradiat…
In this work, charge collection profiles of non-irradiated and irradiated 150 $μ$m $p$-type pad diodes were measured using a 5.2 GeV electron beam traversing the diode parallel to the readout electrode. Four diodes were irradiated to 1 MeV neutron equivalent fluences of 2, 4, 8, and 12E15 {cm}^{-2} with 23 MeV protons. The Charge Collection Efficiency profiles as a function of depth are extracted by unfolding the data. The results of the measurements are compared to the simulation using three radiation damage models from literature which were tuned to different irradiation types and fluences.
The understanding of the weighting field of irradiated silicon sensors is essential for calculating the response of silicon detectors in the radiation environment at accelerators like at the CERN LHC. Using 1-D calculations of non-irradiated pad sensors and 1-D TCAD simulations of pad sensors before and after irradiation, it is shown that the time-dependence of the weighting field is related to the resistivity of low field regions with ohmic behaviour in the sensor. A simple formula is derived, which relates the time constant of the time-dependent weighting field, $τ$, with the resistivity and…
HV-CMOS pixel sensors are a promising option for the tracker upgrade of the ATLAS experiment at the LHC, as well as for other future tracking applications in which large areas are to be instrumented with radiation-tolerant silicon pixel sensors. We present results of testbeam characterisations of the $4^{\mathrm{th}}$ generation of Capacitively Coupled Pixel Detectors (CCPDv4) produced with the ams H18 HV-CMOS process that have been irradiated with different particles (reactor neutrons and 18 MeV protons) to fluences between $1\cdot 10^{14}$ and $5\cdot 10^{15}$ 1-MeV-n$_\textrm{eq}$/cm$^2$. T…
We are investigating the feasibility of using CMOS foundries to fabricate silicon detectors, both for pixels and for large-area strip sensors. The availability of multi-layer routing will provide the freedom to optimize the sensor geometry and the performance, with biasing structures in poly-silicon layers and MIM-capacitors allowing for AC coupling. A prototyping production of strip test-structures and RD53A compatible pixel sensors was recently completed at LFoundry in a 150$\,$nm CMOS process. This paper will focus on the characterization of irradiated and non-irradiated pixel modules, comp…
For the high-luminosity phase of the Large Hadron Collider (HL-LHC), at the expected position of the innermost pixel detector layer of the CMS and ATLAS experiments, the estimated equivalent neutron fluence after 3000 fb$^{-1}$ is 2$\cdot$10$^{16}$ n$_{eq}$/cm$^2$, and the IEL (Ionizing Energy Loss) dose in the SiO$_2$ 12 MGy. The optimisation of the pixel sensors and the understanding of their performance as a function of fluence and dose makes a radiation damage model for TCAD simulations, which describes the available experimental data, highly desirable. The currently available bulk-damage …
Simulation and hit reconstruction of irradiated pixel sensors for the CMS experiment
本文通过对像素传感器辐照损伤的详细仿真，研究了辐射损伤对位置确定的影响，并对命中重建算法进行了优化。模拟实现了一个模型的辐射损伤，包括两个缺陷的水平与相反的电荷状态和捕获的载流子。模拟结果表明，当辐照能量密度为$5.9\times10^{14}$ n $_{\rm{eq}}/$ cm $^2$时，沿CMS $r-ϕ$平面的位置分辨率低于15 $μ$ m。此外，我们表明，在位置确定的系统误差可以大大减少通过应用$η$校正。
Silicon detectors based on the HV-CMOS technology are being investigated as possible candidate for the outer layers of the ATLAS pixel detector for the High Luminosity LHC. In this framework the H35Demo ASIC has been produced in the 350 nm AMS technology (H35). The H35Demo chip has a large area ($18.49 \times 24.40 \, \mathrm{mm^2}$) and includes four different pixel matrices and three test structures. In this paper the radiation hardness properties, in particular the evolution of the depletion region with fluence is studied using edge-TCT on test structures. Measurements on the test structure…
Test beam results obtained with 3D pixel sensors bump-bonded to the RD53A prototype readout ASIC are reported. Sensors from FBK (Italy) and IMB-CNM (Spain) have been tested before and after proton-irradiation to an equivalent fluence of about $1$ $\times$ $10^{16}$ $\text{n}_{\text{eq}}$ cm$^{-2}$ (1 MeV equivalent neutrons). This is the first time that one single collecting electrode fine pitch 3D sensors are irradiated up to such fluence bump-bonded to a fine pitch ASIC. The preliminary analysis of the collected data shows no degradation on the hit detection efficiencies of the tested sensor…
The unique electrical and material properties of 4H-silicon-carbide (4H-SiC) make it a promising candidate material for high rate particle detectors. In contrast to the ubiquitously used silicon (Si), 4H-SiC offers a higher carrier saturation velocity and larger breakdown voltage, enabling a high intrinsic time resolution and mitigating pile-up effects. Additionally, as radiation hardness requirements grow more demanding, wide-bandgap materials such as 4H-SiC could offer better performance. In this work, the detector performance of 50 micron thick 4H-SiC p-in-n planar pad sensors was investiga…
Low Gain Avalanche Detectors (LGADs) are a type of thin silicon detector with a highly doped gain layer. LGADs manufactured by Fondazione Bruno Kessler (FBK) were tested before and after irradiation with neutrons. In this study, the Inter-pad distances (IPDs), defined as the width of the distances between pads, were measured with a TCT laser system. The response of the laser was tuned using $β$-particles from a 90Sr source. These insensitive "dead zones" are created by a protection structure to avoid breakdown, the Junction Termination Extension (JTE), which separates the pads. The effect of n…
A new generation of 3D silicon pixel detectors with a small pixel size of 50$\times$50 and 25$\times$100 $μ$m$^{2}$ is being developed for the HL-LHC tracker upgrades. The radiation hardness of such detectors was studied in beam tests after irradiation to HL-LHC fluences up to $1.4\times10^{16}$ n$_{\mathrm{eq}}$/cm$^2$. At this fluence, an operation voltage of only 100 V is needed to achieve 97% hit efficiency, with a power dissipation of 13 mW/cm$^2$ at -25$^{\circ}$C, considerably lower than for previous 3D sensor generations and planar sensors.
Edge-TCT and charge collection measurements with passive test structures made in LFoundry 150 nm CMOS process on p-type substrate with initial resistivity of over 3 k$Ω$cm are presented. Measurements were made before and after irradiation with reactor neutrons up to 2$\cdot$10$^{15}$ n$_{\mathrm{eq}}$/cm$^2$. Two sets of devices were investigated: unthinned (700 $μ$m) with substrate biased through the implant on top and thinned (200 $μ$m) with processed and metallised back plane. Depleted depth was estimated with Edge-TCT and collected charge was measured with $^{90}$Sr source using an externa…
A method is presented which allows to obtain the position-dependent electric field and charge density by fits to velocity profiles from edge-TCT data from silicon strip-detectors. The validity and the limitations of the method are investigated by simulations of non-irradiated $n^+p$ pad sensors and by the analysis of edge-TCT data from non-irradiated $n^+p$ strip-detectors. The method is then used to determine the position dependent electric field and charge density in $n^+p$ strip detectors irradiated by reactor neutrons to fluences between 1 and $10 \times 10^{15}$ cm$^{-2}$ for forward-bias…
Investigation of HV-CMOS sensors for use as a tracking detector in the ATLAS experiment at the upgraded LHC (HL-LHC) has recently been an active field of research. A potential candidate for a pixel detector built in Silicon-On-Insulator (SOI) technology has already been characterized in terms of radiation hardness to TID (Total Ionizing Dose) and charge collection after a moderate neutron irradiation. In this article we present results of an extensive irradiation hardness study with neutrons up to a fluence of 1x10e16 neq/cm2. Charge collection in a passive pixelated structure was measured by …
In this paper the results of a beam test characterization campaign of 3D trench silicon pixel sensors are presented. A time resolution in the order of 10 ps was measured both for non-irradiated and irradiated sensors up to a fluence of $2.5 \cdot 10^{16}\,1\,MeV\, n_{eq}\,cm^{-2}$. This feature and a detection efficiency close to $99\%$ make this sensors one of the best candidates for 4D tracking detectors in High-Energy-Physics experiments.
Signal and noise of Diamond Pixel Detectors at High Radiation Fluences
CVD金刚石由于其大的带隙和强的晶格结构而具有很强的抗辐射性，是LHC顶点探测器的一种有吸引力的材料选择。特别地，在相互作用点附近操作的像素检测器受益于金刚石的微小漏电流和小像素电容，从而与硅相比具有低噪声系数。另一方面，来自穿越高能粒子的电荷信号在金刚石中比在硅中小约2.2倍。因此，在超过10 $^{15}$ n $_{eq}$ cm $^{-2}$的注量下，与硅相比，定量测定金刚石的信噪比（S/N）是重要的，这是LHC升级所期望的。基于对辐照金刚石传感器的测量和FE-I4像素读出芯片的设计，我们确定了高粒子注量辐照金刚石像素探测器的信号和噪声。为了表征辐射损伤对材料和信号降低的影响，将载流子的平均自由程$λ_{e/h}$的变化确定为辐射通量的函数。我们利用为ATLAS升级开发的FE-I4像素芯片来实际估计预期的噪声系数：给定通量下的预期漏电流来自校准计算，像素电容使用专门开发的芯片（PixCap）测量。我们比较所得的S/N数字与平面硅像素探测器使用公布的电荷损失测量和相同的外推方法，为金刚石。它示出，预期的S/N的金刚石像素探测器与像素间距典型的LHC，超过平面硅像素在超过10 $^{15}$粒子cm $^{-2}$的注量，确切的值仅取决于最大的操作电压假设为辐照硅像素探测器。
Planar silicon pixel sensors with modified n$^+$-implantation shapes based on the IBL pixel sensor were designed in Dortmund. The sensors with a pixel size of $250\,μ$m $\times$ $50\,μ$m are produced in n$^+$-in-n sensor technology. The charge collection efficiency should improve with electrical field strength maxima created by the different n$^+$-implantation shapes. Therefore, higher particle detection efficiencies at lower bias voltages could be achieved. The modified pixel designs and the IBL standard design are placed on one sensor to test and compare the designs. The sensor can be read o…
A significant aspect of the Phase-II Upgrade of the ATLAS detector is the replacement of the current Inner Detector with the ATLAS Inner Tracker (ITk). The ATLAS ITk is an all-silicon detector consisting of a pixel tracker and a strip tracker. Sensors for the ITk strip tracker have been developed to withstand the high radiation environment in the ATLAS detector after the High Luminosity Upgrade of the Large Hadron Collider at CERN, which will significantly increase the rate of particle collisions and resulting particle tracks. During their operation in the ATLAS detector, sensors for the ITk s…
Small-pitch 3D silicon pixel detectors have been investigated as radiation-hard candidates for the innermost layers of the HL-LHC pixel detector upgrades. Prototype 3D sensors with pixel sizes of 50$\times$50 and 25$\times$100 $μ$m$^{2}$ connected to the existing ATLAS FE-I4 readout chip have been produced by CNM Barcelona. Irradiations up to particle fluences of $3\times10^{16}$ n$_{\mathrm{eq}}$/cm$^2$, beyond the full expected HL-LHC fluences at the end of lifetime, have been carried out at Karlsruhe and CERN. The performance of the 50$\times$50 $μ$m$^{2}$ devices has been measured in the l…
Pixelated silicon detectors are state-of-the-art technology to achieve precise tracking and vertexing at collider experiments, designed to accurately measure the hit position of incoming particles in high rate and radiation environments. The detector requirements become extremely demanding for operation at the High-Luminosity LHC, where up to 200 interactions will overlap in the same bunch crossing on top of the process of interest. Additionally, fluences up to 2.3 10^16 cm^-2 1 MeV neutron equivalent at 3.0 cm distance from the beam are expected for an integrated luminosity of 3000 fb^-1. In …
The tracking detector of ATLAS, one of the experiments at the Large Hadron Collider (LHC), will be upgraded in 2024-2026 to cope with the challenging environment conditions of the High Luminosity LHC (HL-LHC). The LPNHE, in collaboration with FBK and INFN, has produced 130~$μ$m thick $n-on-p$ silicon pixel sensors which can withstand the expected large particle fluences at HL- LHC, while delivering data at high rate with excellent hit efficiency. Such sensors were tested on beam before and after irradiation both at CERN-SPS and at DESY, and their performances are presented in this paper. Beam …
The ATLAS experiment at the LHC will replace its current inner tracker system for the HL-LHC era. 3D silicon pixel sensors are being considered as radiation-hard candidates for the innermost layers of the new fully silicon-based tracking detector. 3D sensors with a small pixel size of $\mathrm{50 \times 50~μm^{2}}$ and $\mathrm{25 \times 100~μm^{2}}$ compatible with the first prototype ASIC for the HL-LHC, the RD53A chip, have been studied in beam tests after uniform irradiation to $\mathrm{5 \times 10^{15}~n_{eq}/cm^{2}}$. An operation voltage of only 50 V is needed to achieve a 97% hit effic…
In this paper the weighting field $E_W$ and the frequency dependence of the admittance Y of n$^+$p pad sensors irradiated by 24 GeV/c protons to equivalent fluences in the range $Φ_{\rm eq} = 3$ to $13\times 10^{15}$ cm$^{-2}$ are investigated. 1-D TCad simulations are used to calculate $E_W$. For $Φ_{\rm eq} < 10^{13}$ cm$^{-2}$ $E_W$ depends on position and time. However, for higher $Φ_{\rm eq}$ the time constant $τ$ is much longer than the typical electronics readout time and $E_W = 1/d$ ($d$ = sensor thickness). It is demonstrated that the increase of the resistivity of the Si bulk with ir…
Charge collection properties of depleted CMOS pixel detector prototypes produced on p-type substrate of 2 k$Ω$cm initial resistivity (by LFoundry 150 nm process) were studied using Edge-TCT method before and after neutron irradiation. The test structures were produced for investigation of CMOS technology in tracking detectors for experiments at HL-LHC upgrade. Measurements were made with passive detector structures in which current pulses induced on charge collecting electrodes could be directly observed. Thickness of depleted layer was estimated and studied as function of neutron irradiation …
