Recent advancements in particle physics demand pixel detectors that can withstand increased luminosity in the future collider experiments. In response, MALTA, a novel monolithic active pixel detector, has been developed with a cutting-edge readout architecture. This new class of monolithic pixel detectors is found to have exceptional radiation tolerance, superior hit rates, higher resolution and precise timing resolution, making them ideally suited for experiments at the LHC. To optimize the performance of these sensors before their deployment in actual detectors, comprehensive electrical characterization has been conducted. This study also includes comparative DAC analyses among sensors of varying thicknesses, providing crucial insights for performance enhancement. For the further understanding of the effect of radiation, the sensors are being exposed to different fluence using high intensity X-ray source.
This paper presents the experimental results of $17~MeV$ proton irradiation on a $60~GHz$ low power, half-duplex transceiver (TRX) chip implemented in $65~nm$ CMOS technology. It supports short range point-to-point data rate up to $6~Gbps$ by employing on-off keying (OOK). To investigate the irradiation hardness for high energy physics applications, two TRX chips were irradiated with total ionizing doses (TID) of $74~kGy$ and $42~kGy$ and fluence of $1.4~\times$10$^{14}~ N_{eq}/cm^2$ and $0.8~\times$10$^{14}~N_{eq}/cm^2$ for RX and TX modes, respectively. The chips were characterized by pre- a…
In this paper results of Edge-TCT and I-V measurements with passive test structures made in LFoundry 150 nm HV-CMOS process on p-type substrates with different initial resistivities ranging from 0.5 to 3 k$Ω$cm are presented. Samples were irradiated with reactor neutrons up to a fluence of 2$\cdot$10$^{15}$ n$_{\mathrm{eq}}$/cm$^2$. Depletion depth was measured with Edge-TCT. Effective space charge concentration $N_{\mathrm{eff}}$ was estimated from the dependence of depletion depth on bias voltage and studied as a function of neutron fluence. Dependence of $N_{\mathrm{eff}}$ on fluence change…
Characterization of Passive CMOS Strip Detectors After Proton Irradiation
TU Dortmund（多特蒙德工业大学）；Deutsches Elektronen Synchrotron DESY（德国电子同步加速器中心）；University of Bonn（波恩大学）；Albert-Ludwigs-Universität Freiburg（弗赖堡大学）；Fachhochschule Dortmund（多特蒙德应用技术大学）
This paper reports on the characterisation with Transient Current Technique measurements of the charge collection and depletion depth of a radiation-hard high-voltage CMOS pixel sensor produced at ams AG. Several substrate resistivities were tested before and after proton irradiation with two different sources: the 24 GeV Proton Synchrotron at CERN and the 16.7 MeV Cyclotron at Bern Inselspital.
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 …
High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) based on the 180 nm HV-CMOS process have been proposed to realize thin, fast and highly integrated pixel sensors. The MuPix7 prototype, fabricated in the commercial AMS H18 process, features a fully integrated on-chip readout, i.e. hit-digitization, zero suppression and data serialization. It is the first fully monolithic HV-CMOS pixel sensor that has been tested for the use in high irradiation environments like HL-LHC. We present results from laboratory and test beam measurements of MuPix7 prototypes irradiated with neutrons (up to $5.0\c…
Deep sub micron HV-CMOS processes offer the opportunity for sensors built by industry standard techniques while being HV tolerant, making them good candidates for drift-based, fast collecting, thus radiation-hard pixel detectors. For the upgrade of the ATLAS Pixel Detector towards the HL-LHC requirements, active pixel sensors in HV-CMOS technology were investigated. These implement amplifier and discriminator stages directly in insulating deep n-wells, which also act as collecting electrodes. The deep n-wells allow for bias voltages up to 150V leading to a depletion depth of several 10um. Prot…
Pixel sensors using 8" CMOS processing technology have been designed and characterized offering the benefits of industrial sensor fabrication, including large wafers, high throughput and yield, as well as low cost. The pixel sensors are produced using a 150 nm CMOS technology offered by LFoundry in Avezzano. The technology provides multiple metal and polysilicon layers, as well as metal-insulator-metal capacitors that can be employed for AC-coupling and redistribution layers. Several prototypes were fabricated and are characterized with minimum ionizing particles before and after irradiation t…
Recent advances in CMOS imaging sensor technology , e.g. in CMOS pixel sensors, have proven that the CMOS process is radiation tolerant enough to cope with certain radiation levels required for tracking layers in hadron collider experiments. With the ever-increasing area covered by silicon tracking detectors cost effective alternatives to the current silicon sensors and more integrated designs are desirable. This article describes results obtained from laboratory measurements of silicon strip sensors produced in a passive p-CMOS process. Electrical characterization and charge collection measur…
We report on the effects of ionizing radiation on 65nm CMOS transistors held at approximately -20C during irradiation. The pattern of damage observed after a total dose of 1 Grad is similar to damage reported in room temperature exposures, but we observe less damage than was observed at room temperature.
In view of the tracking detector application to the ATLAS High Luminosity LHC (HL-LHC) upgrade, we have developed a new generation of High Voltage CMOS (HV-CMOS) monolithic pixel-sensor prototypes featuring the AMS aH18 (180 nm) commercial CMOS technology. By fully integrating both analog and digital readout-circuitry on the same particle-detecting substrate, current challenges of hybrid sensor technologies, i.e., larger readout input-capacitance, lower production-yield, and higher production and integration cost, can be downscaled. The large electrode design using high-resistivity substrates …
The CERN-RD50 CMOS working group develops the RD50-MPWseries of monolithic high-voltage CMOS pixel sensors for potential use in future high luminosity experiments such as the HL-LHC and FCC-hh. In this contribution, the design of the latest prototype in this series, RD50-MPW3, is presented. An overview of its pixel matrix and digital readout periphery is given, with discussion of the new structures implemented in the chip and the problems they aim to solve. The main analog and digital features of the sensor are already tested and initial laboratory characterisation of the chip is presented.
CLICTD is a monolithic silicon pixel sensor fabricated in a modified 180 nm CMOS imaging process with a small collection electrode design and a high-resistivity epitaxial layer. It features an innovative sub-pixel segmentation scheme and is optimised for fast charge collection and high spatial resolution. The sensor was developed to target the requirements for the tracking detector of the proposed future Compact Linear Collider (CLIC). Most notably, a temporal resolution of a few nanoseconds and a spatial resolution below 7 microns are demanded. In this contribution, the sensor performance mea…
A CMOS pixel sensor, named Supix-1, is developed for a pixelated silicon tracker for the Circular Electron-Positron Collider (CEPC) project. The sensor, consisted of nine sectors varying in pixel sizes, diode sizes and geometries, is fabricated with a 180 nm CMOS Image Sensor (CIS) process to study the particle detection performance of enlarged pixels. In this work, the radiation-induced effects on the charge collection of the sensor under the fluence of 1 $\times$ 10^13 1 MeV neq/cm^2 are studied by the measurements with the radioactive source of Fe-55 and the Technology Computer Aided Design…
The use of CMOS Pixel Sensors (CPS) for high resolution and low material vertex detectors has been validated with the 2014 and 2015 physics runs of the STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner tracking devices, with 10-100 times larger sensitive area, which require therefore a sensor design privileging power saving, response uniformity and robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was considered as too poorly suited to upcoming applications like the upgraded ALICE Inner Tracking System (ITS), which requires sensors with one order…
CMOS Monolithic Active Pixel Sensors (CPS) are ultra-light and highly granular silicon pixel detectors suited for highly sensitive charged particle tracking. Being manufactured with cost efficient standard CMOS processes, CPS may integrate sensing elements together with analogue and digital data processing circuits into one monolithic chip. This turns into $50~\rm μm$ thin sensors, which provide an outstanding typical spatial resolution of few $~\rm μm$ and a detection efficiency for minimum ionizing particles above $99.9\%$. The radiation tolerance of CPS was initially constrained by the limi…
Active pixel sensors based on the High-Voltage CMOS technology are being investigated as a viable option for the future pixel tracker of the ATLAS experiment at the High-Luminosity LHC. This paper reports on the testbeam measurements performed at the H8 beamline of the CERN Super Proton Synchrotron on a High-Voltage CMOS sensor prototype produced in 180 nm AMS technology. Results in terms of tracking efficiency and timing performance, for different threshold and bias conditions, are shown.
CMOS Pixel Sensors are making steady progress towards the specifications of the ILD vertex detector. Recent developments are summarised, which show that these devices are close to comply with all major requirements, in particular the read-out speed needed to cope with the beam related background. This achievement is grounded on the double- sided ladder concept, which allows combining signals generated by a single particle in two different sensors, one devoted to spatial resolution and the other to time stamp, both assembled on the same mechanical support. The status of the development is overv…
The recent R&D focus on CMOS sensors with charge collection in a depleted zone has opened new perspectives for CMOS sensors as fast and radiation hard pixel devices. These sensors, labelled as depleted CMOS sensors (DMAPS), have already shown promising performance as feasible candidates for the ATLAS Inner Tracker (ITk) upgrade, possibly replacing the current passive sensors. A further step to exploit the potential of DMAPS is to investigate the suitability of equipping the outer layers of the ATLAS ITk upgrade with fully monolithic CMOS sensors. This paper presents the development of a deplet…
Swift, high resolution CMOS pixel sensors are being developed for the ILC vertex detector, aiming to allow approaching the interaction point very closely. A major issue is the time resolution of the sensors needed to deal with the high occupancy generated by the beam related background. A 128x576 pixel sensor providing digitised outputs at a read-out time of 92.5 us, was fabricated in 2008 within the EU project EUDET, and tested with charged particles at the CERN-SPS. Its prominent performances in terms of noise, detection efficiency versus fake hit rate, spatial resolution and radiation toler…
High Energy Particle Physics experiments at the LHC use hybrid silicon detectors, in both pixel and strip geometry, for their inner trackers. These detectors have proven to be very reliable and performant. Nevertheless, there is great interest in the development of depleted CMOS silicon detectors, which could achieve similar performances at lower cost of production and complexity. We present recent developments of this technology in the framework of the ATLAS CMOS demonstrator project. In particular, studies of two active sensors from LFoundry, CCPD_LF and LFCPIX, and the first fully monolithi…
Monolithic active pixel sensors (MAPS) are now well established as a technology for tracking charged particles, especially when low material budget is desirable. For such applications, sensors focus on spatial resolution and pixels with digital output or modest charge measurement ability are well suited. Within the European Union STRONG-2020 project, which focuses on experiments using hadrons, the TIIMM (Tracking and Ions Identifications with Minimal Material budget) joint research activity intends to expand granular MAPS capacity to energy-loss (ΔE) measurement for ion species identification.…
This work presents a depleted monolithic active pixel sensor (DMAPS) prototype manufactured in the LFoundry 150 nm CMOS process. The described device, named LF-Monopix, was designed as a proof of concept of a fully monolithic sensor capable of operating in the environment of outer layers of the ATLAS Inner Tracker upgrade for the High Luminosity Large Hadron Collider (HL-LHC). Implementing such a device in the detector module will result in a lower production cost and lower material budget compared to the presently used hybrid designs. In this paper the chip architecture will be described foll…
CMOS Pixel Sensors tend to become relevant for a growing spectrum of charged particle detection instruments. This comes mainly from their high granularity and low material budget. However, several potential applications require a higher read-out speed and radiation tolerance than those achieved with available devices based on a 0.35 micrometers feature size technology. This paper shows preliminary test results of new prototype sensors manufactured in a 0.18 micrometers process based on a high resistivity epitaxial layer of sizeable thickness. Grounded on these observed performances, we discuss…
Both the current upgrades to accelerator-based HEP detectors (e.g. ATLAS, CMS) and also future projects (e.g. CEPC, FCC) feature large-area silicon-based tracking detectors. We are investigating the feasibility of using CMOS foundries to fabricate silicon radiation detectors, both for pixels and for large-area strip sensors. A successful proof of concept would open the market potential of CMOS foundries to the HEP community, which would be most beneficial in terms of availability, throughput and cost. In addition, the availability of multi-layer routing of signals will provide the freedom to o…
The CLIC Tracker Detector (CLICTD) is a monolithic pixel sensor featuring pixels of 30um x 37.5um and a small collection diode. The sensor is fabricated in a 180 nm CMOS imaging process, using two different pixel flavours: the first with a continuous n-type implant for full lateral depletion, and the second with a segmentation in the n-type implant for accelerated charge collection. Moreover, CLICTD features an innovative sub-pixel segmentation scheme that allows the digital footprint to be reduced while maintaining a small sub-pixel pitch. In this contribution, test-beam measurements for the …
The LHC Phase-II upgrade will lead to a significant increase in luminosity, which in turn will bring new challenges for the operation of inner tracking detectors. A possible solution is to use active silicon sensors, taking advantage of commercial CMOS technologies. Currently ATLAS R&D programme is qualifying a few commercial technologies in terms of suitability for this task. In this paper a prototype designed in one of them (LFoundry 150 nm process) will be discussed. The chip architecture will be described, including different pixel types incorporated into the design, followed by simulation…
This paper presents development and characterization of a 3.2 Gb/s serial link transmitter for CMOS image sensors. The transmitter incorporates Reed-Solomon code to achieve low error rate in the harsh environment of subatomic physics experiments. Pre-emphasis is implemented in the transmitter, allowing data transmission over low-mass cables. It is fabricated in a 0.18 $μm$ CMOS image process as a standalone chip to characterize its performance, with the core area of 1.8 $mm^2$. A frame data rate of $3\cdot10^{-12}$ with a confidence level of 94.5$\%$ was measured through an FPGA based receiver…
CMOS pixel sensors (CPS) represent a novel technological approach to building charged particle detectors. CMOS processes allow to integrate a sensing volume and readout electronics in a single silicon die allowing to build sensors with a small pixel pitch ($\sim 20 μm$) and low material budget ($\sim 0.2-0.3\% X_0$) per layer. These characteristics make CPS an attractive option for vertexing and tracking systems of high energy physics experiments. Moreover, thanks to the mass production industrial CMOS processes used for the manufacturing of CPS the fabrication construction cost can be signifi…
Purpose: CMOS pixel sensors have become extremely attractive for future high performance tracking devices. Initial R\&D work has been conducted for the vertex detector for the proposed Circular Electron Positron Collider that will allow precision Higgs measurements. It is critical to achieve low power consumption to minimize the material budget. This requires careful optimization of the sensor diode geometry to reach high charge-over-capacitance that allows reduction in analog power consumption. Methods: The electrode area and footprint are two critical elements in sensor diode geometry and ha…
Monolithic active pixel sensors produced in High Voltage CMOS (HV-CMOS) technology are being considered for High Energy Physics applications due to the ease of production and the reduced costs. Such technology is especially appealing when large areas to be covered and material budget are concerned. This is the case of the outermost pixel layers of the future ATLAS tracking detector for the HL-LHC. For experiments at hadron colliders, radiation hardness is a key requirement which is not fulfilled by standard CMOS sensor designs that collect charge by diffusion. This issue has been addressed by …
CMOS Monolithic Active Pixel Sensors (MAPS) were chosen as sensor technology for the vertex detectors of STAR, CBM and the upgraded ALICE-ITS. They also constitute a valuable option for tracking devices at future e+e- colliders. Those applications require a substantial tolerance to both, ionizing and non-ionizing radiation. To allow for a focused optimization of the radiation tolerance, prototypes are tested by irradiating the devices either with purely ionizing radiation (e.g. soft X-rays) or the most pure sources of non-ionizing radiation available (e.g. reactor neutrons). In the second case…
The CLIC Tracker Detector (CLICTD) is a monolithic pixelated sensor chip produced in a $180$ nm imaging CMOS process built on a high-resistivity epitaxial layer. The chip, designed in the context of the CLIC tracking detector study, comprises a matrix of ${16\times128}$ elongated pixels, each measuring ${300\times30}$ $μ$m$^2$. To ensure prompt charge collection, every elongated pixel is segmented in eight sub-pixels, each containing a collection diode and a separate analog front-end. A simultaneous $8$-bit time measurement with $10$ ns time bins and $5$-bit energy measurement with programmabl…
The planned luminosity increase at the Large Hadron Collider in the coming years has triggered interest in the use of the particles' time of arrival as additional information in specialized detectors to mitigate the impact of pile-up. The required time resolution is of the order of tens of picoseconds, with a spatial granularity of the order of 1 mm. A time measurement at this precision level will also be of interest beyond the LHC and beyond high energy particle physics. We present in this paper the first developments towards a radiation hard Depleted Monolithic Active Pixel Sensor (DMAPS), w…
A prototype of a Si-W EM calorimeter was built with Monolithic Active Pixel Sensors as the active elements. With a pixelsize of 30 $μ$m it allows digital calorimetry, i.e. the particles' energy is determined by counting pixels, not by measuring the energy deposited. Although of modest size, with a width of only four Moliere radii, it has 39 million pixels. We describe the construction and tuning of the prototype and present results from beam tests and compare them with predictions of GEANT-based Monte Carlo simulations. We show the shape of showers caused by electrons in unprecedented detail. …
CMOS sensors were successfully implemented in the STAR tracker [1]. LHC experiments have shown that efficient b tagging, reconstruction of displaced vertices and identification of disappearing tracks are necessary. An improved vertex detector is justified for the ILC. To achieve a point(spatial single layer) resolution below the one-μm range while improving other characteristics (radiation tolerance and eventually time resolution) we will need the use of 1-micron pitch pixels. Therefore, we propose a single MOS transistor that acts as an amplifying device and a detector with a buried charge-co…
The upgrade to the High Luminosity Large Hadron Collider will pose unprecedented challenges to the tracking systems of all experiments. Recent advancement of active pixel detectors designed in CMOS processes provide attractive alternatives to the well-established hybrid design using passive sensors. This article presents studies with a high-voltage CMOS active pixel sensor designed for the ATLAS tracker upgrade. The sensor is glued to the read-out chip of the Insertable B-Layer. The device under test is structured in smaller pixels than those of the attached read-out chip with information on t…
- Paper withdrawn by the author - CMOS Monolithic Active Pixel Sensors for charged particle tracking are considered as technology for numerous experiments in heavy ion and particle physics. To match the requirements for those applications in terms of tolerance to non-ionizing radiation, it is being tried to deplete the sensitive volume of the, traditionally non-depleted, silicon sensors. We study the feasibility of this approach for the common case that the collection diodes of the pixel are small as compared to the pixel pitch. An analytic equation predicting the thickness of the depletion de…
A cluster imaging technique for Transmission Electron Microscopy with a direct detection CMOS pixel sensor is presented. Charge centre-of-gravity reconstruction for individual electron clusters improves the spatial resolution and thus the point spread function. Data collected with a CMOS sensor with 9.5 micron pixels show an improvement of a factor of two in point spread function to 2.7 micron at 300 keV and of a factor of three in the image contrast, compared to traditional bright field illumination.
Proton irradiation effects on a Single-Photon Avalanche Diodes (SPADs) device manufactured using a 150-nm CMOS process are presented. An irradiation campaign has been carried out with protons of 20 MeV and 24 MeV on several samples of a test chip containing SPADs arrays with two different junction layouts. The dark count rate distributions have been analyzed as a function of the displacement damage dose. Annealing and cooling have been investigated as possible damage mitigation approaches. We also discuss, through a space radiation simulation, the suitability of such devices on several space m…
This paper reviews the development of CMOS Monolithic Active Pixel Sensors (MAPS) for future vertex detectors. MAPS are developed in a standard CMOS technology. In the imaging field, where the technology found its first applications, they are also known as CMOS Image Sensors. The use of MAPS as a detector for particle physics was first proposed at the end of 1999. Since then, their good performance in terms of spatial resolution, efficiency, radiation hardness have been demonstrated and work is now well under way to deliver the first MAPS-based vertex detectors.
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…
We present a study of a CMOS test sensor which has been designed, fabricated and characterised to investigate the parameters required for a binary readout electromagnetic calorimeter. The sensors were fabricated with several enhancements in addition to standard CMOS processing. Detailed simulations and experimental results of the performance of the sensor are presented. The sensor and pixels are shown to behave in accordance with expectations and the processing enhancements are found to be essential to achieve the performance required.
The radiation hardness of passive CMOS pixel sensors fabricated in 150 nm LFoundry technology is investigated. CMOS process lines are especially of interest for large-scale silicon detectors as they offer high production throughput at comparatively low cost. Moreover, several features like poly-silicon resistors, MIM-capacitors and several metal layers are available which can help enhance the sensor design. The performance of a 100 $\mathrmμ$m thin passive CMOS sensor with a pixel pitch of 50 $\mathrmμ$m at different irradiation levels, 5 $\times$ 10$^{15}$n$_{\mathrm{eq}}$cm$^{-2}$ and 1 $\ti…
We report on the experimental study made on a successive prototype of High-Voltage CMOS (HV-CMOS) ATLASPix2 sensor for the tracking detector application, developed with 180 nm feature size. These sensors are to qualify mainly the peripheral data processing blocks (e.g. Command Decoder, Trigger Buffer, etc.). It is a smaller version of 24 X 36 pixelated sensor in comparison to the earlier generation of ATLASPix1 fabricated in both ams AG, Austria, and TSI Semiconductors, USA. While ams produced ATLASPix2 showed breakdown voltage 50 V in nonirradiated condition as it was seen on its predecessors…
CMOS Image Sensors for CEvNS Detection at Nuclear Reactors
University of Chicago（芝加哥大学）；Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales（布宜诺斯艾利斯大学理学院）；CONICET, Universidad de Buenos Aires, Instituto de Física de Buenos Aires (IFIBA)（阿根廷国家科学研究委员会，布宜诺斯艾利斯大学，布宜诺斯艾利斯物理研究所）；CONICET, Instituto de Física Enrique Gaviola (IFEG), Comisión Nacional de Energía Atómica (CNEA) and Universidad Nacional de Córdoba（阿根廷国家科学研究委员会，恩里克·加维奥拉物理研究所，国家原子能委员会和科尔多瓦国立大学）
The apparatus of the ALICE experiment at CERN will be upgraded in 2017/18 during the second long shutdown of the LHC (LS2). A major motivation for this upgrade is to extend the physics reach for charmed and beauty particles down to low transverse momenta. This requires a substantial improvement of the spatial resolution and the data rate capability of the ALICE Inner Tracking System (ITS). To achieve this goal, the new ITS will be equipped with 50 um thin CMOS Pixel Sensors (CPS) covering either the 3 innermost layers or all the 7 layers of the detector. The CPS being developed for the ITS upg…
The detection of photons produced during the avalanche development in gas chambers has been the subject of detailed studies in the past. The great progresses achieved in last years in the performance of micro-pattern gas detectors on one side and of photo-sensors on the other provide the possibility of making high granularity and very sensitive particle trackers. In this paper, the results obtained with a triple-GEM structure read-out by a CMOS based sensor are described. The use of an He/CF$_4$ (60/40) gas mixture and a detailed optimization of the electric fields made possible to obtain and …
Conventional x-ray imaging detectors suffer from parallax error when the radiation beam arrives at the detector surface at tilted angle. The image blurring occurs as the radiation penetrates detector material in lateral direction at tilted angle. However, at the photon energies used in x-ray microscopy the attenuation length of the x-rays in the detector material is shorter and consequently the parallax error due to the tilted angle irradiation can be smaller. In these cases, the tilted angle irradiation can be beneficial because it will expand the beam projection ("footprint") at the detector…
