MALTA monolithic pixel sensors in TowerJazz 180 nm technology Solans Sánchez, C.; Allport, P.; Asensi Tortajada, I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2023, Letnik:
1057
Journal Article
Recenzirano
Odprti dostop
Depleted Monolithic Active Pixel Sensors are of highest interest at the HL-LHC and beyond for the replacement of the Pixel trackers in the outermost layers of experiments where the requirement on ...total area and cost effectiveness is much bigger. They aim to provide high granularity and low material budget over large surfaces with ease of integration. Our research focuses on MALTA, a radiation hard DMAPS with small collection electrode designed in TowerJazz 180 nm CMOS imaging technology and asynchronous read-out. Latest prototypes are radiation hard up to 2 × 1015 1 MeV neq/cm2 with a time resolution better than 2 ns.
The MALTA monolithic silicon pixel sensors have been used to study dicing and thinning of monolithic silicon pixel detectors for large area and low mass modules. Dicing as close as possible to the ...active circuitry will allow to build modules with very narrow inactive regions between the sensors. Inactive edge regions of less than 5μ m to the electronic circuitry could be achieved for 100μm thick sensors. The MALTA chip (Cardella et al., 2019) also offers the possibility to transfer data and power directly from chip to chip. Tests have been carried out connecting two MALTA chips directly using ultrasonic wedge wire bonding. Results from lab tests show that the data accumulated in one chip can be transferred via the second chip to the readout system, without the need of a flexible circuit to route the signals. The concept of chip to chip data and power transfer to achieve low mass modules has also been studied on prototype wafers using Cu-stud interconnection bridges. First results are presented, outlining technical challenges and possible future steps to achieve a low mass large area monolithic pixel sensor module.
The last couple of years have seen the development of Depleted Monolithic Active Pixel Sensors (DMAPS) fabricated in TowerJazz 180nm with a process modification to increase the radiation tolerance. ...While many of MAPS developments focus on low radiation environment, we have taken the development to high radiation environment like pp-experiments at High Luminosity LHC. DMAPS are a cost effective and lightweight alternative to state-of-the-art hybrid detectors if they can fulfil the given requirements for radiation hardness, signal response time and hit rate capability. The MALTA and Mini-MALTA sensors have shown excellent detection efficiency after irradiation to the life time dose expected at the outer layers of the ATLAS pixel tracker Upgrade. Our development focuses on providing large pixel matrixes with excellent time resolution (<2ns) and tracking. This publication will discuss characterisation results of the DMAPS devices with special focus on the new MALTA2 sensor and will show the path of future developments
Measurement results of the MALTA monolithic pixel detector Schioppa, E.J.; Asensi Tortajada, I.; Berdalovic, I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
MALTA is a full scale monolithic pixel detector implemented in TowerJazz 180 nm CMOS technology. The small pixel electrode allowed for the implementation of a fast, low noise and low power front-end, ...which is sensitive to the charge released by ionizing radiation in a 20–25 μm deep depleted region. The novel asynchronous matrix architecture is designed to ensure low power consumption and high rate capability. Such features make MALTA a possible candidate for the outer layer of ATLAS Inner Tracker (ITk) upgrade. Unirradiated and irradiated MALTA sensors have been extensively tested in laboratory and with high energy particle beams. Results of this measurements campaign are shown, and the further improvements that are being implemented in the next versions of the chip are discussed.
The last couple of years have seen the development of Depleted Monolithic Active Pixel Sensors (DMAPS) fabricated with a process modification to increase the radiation tolerance. Two large scale ...prototypes, Monopix with a column drain synchronous readout, and MALTA with a novel asynchronous architecture, have been fully tested and characterized both in the laboratory and in test beams. This showed that certain aspects have to be improved such as charge collection after irradiation and the output data rate. Some improvements resulting from extensive TCAD simulations were verified on a small test chip, Mini-MALTA. A detailed cluster analysis, using data from laboratory and test beam studies, at different biases, for high and low thresholds and before and after irradiation is presented, followed by detailed simulations showing that the digital architecture for both chips is capable of dealing with data rates of around 80 MHz/cm2 similar to what it is expected in the outer layer of the ATLAS inner tracker upgrade for the HL-LHC. The data rate capability and output bandwidth are studied using realistic hits generated by the ATLAS detector simulation framework.
MALTA is a depleted monolithic active pixel sensor (DMAPS) developed in the Tower Semiconductor 180-nm CMOS imaging process. Monolithic CMOS sensors offer advantages over current hybrid imaging ...sensors in terms of both increased tracking performance due to lower material budget and ease of integration and construction costs due to the integration of read-out and active sensor into one ASIC. Current research and development efforts are aimed toward radiation hard designs up to 100 Mrad in total ionizing dose (TID) and <inline-formula> <tex-math notation="LaTeX">1\,\, \times 10 ^{15}~1~\text {MeV}\text {n}_{\text {eq}}/\text {cm}^{2} </tex-math></inline-formula> in nonionizing energy loss (NIEL). The design of the MALTA sensors was specifically chosen to achieve radiation hardness up to these requirements and satisfy current and future collider constraints. The current MALTA pixel architecture uses small electrodes which provide less noise, higher signal voltage, and a better power-to-performance ratio. To counteract the loss of efficiency in pixel corners, modifications to the Tower process have been implemented. The MALTA sensors have been tested during the 2021 and 2022 SPS CERN Test Beam in the MALTA telescope. The telescope ran for the whole duration of the beam time and took data to characterize the novel MALTA2 variant and the performance of irradiated samples in terms of efficiency and cluster size. These campaigns show that MALTA is an interesting prospect for HL-LHC and beyond collider experiments, providing both very good tracking capabilities and radiation hardness in harsh radiation environments.
Detector prototypes are commonly characterised in testbeams, either using charged particles or X-rays. Charged particles are used to quantify detector performance in terms of absolute efficiency, ...while X-rays can provide additional information about the detector structure. This paper presents an alternative approach to calculating charged particle efficiencies, using the results of an X-ray testbeam of the mini-MALTA CMOS prototype at Diamond Light Source, and additional laboratory measurements. Results are presented for an unirradiated and an irradiated sample and compared to the results of charged particle testbeams at SPS and ELSA. The extrapolated efficiencies are in agreement with the measured values. Additionally, the extrapolated efficiency maps provide more insight about the location of the pixel inefficiencies, due to the better spatial resolution of the X-ray testbeam.
Quad-module characterization with the MALTA monolithic pixel chip Dachs, F.; Zoubir, A.M.; Sharma, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2024, Letnik:
1064
Journal Article
Recenzirano
The MALTA silicon pixel detector combines a depleted monolithic active pixel sensor (DMAPS) with a fully asynchronous front-end and readout. It features a high granularity pixel matrix with a 36.4 μm ...symmetric pixel pitch, low power consumption of <1 μW/pixel and low material budget with detector thicknesses as little as 50 μm. It achieves a radiation hardness to 100MRad TID and more than 1 × 10E15 1 MeV neq/cm2 with a time resolution of <2 ns (Pernegger et al., 2023).
In order to cover large sensitive areas efficiently with a minimum of power and data connections the development of modules, comprising of up to 4 MALTA detectors, is studied.
This contribution presents the beam test performance of parallel and serial powered MALTA 4-chip modules in an effort to characterize the sensor’s chip-to-chip data and power transmission and prepare the production of a first prototype of an ultra-light weight 4-chip module on a flexible circuit with next generation MALTA2 sensors.
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