Yazar "Berlea, D. V." seçeneğine göre listele

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    MALTA monolithic pixel sensors in TowerJazz 180 nm technology
    (Elsevier, 2023) Sanchez, C. Solans; Allport, P.; Denizli, Haluk; Berlea, D. V.; Oyulmaz, Kaan Yüksel; Bortoletto, D.
    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 x 1015 1 MeV neq/cm2 with a time resolution better than 2 ns.
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    MALTA-Cz: a radiation hard full-size monolithic CMOS sensor with small electrodes on high-resistivity Czochralski substrate
    (IOP Publishing Ltd, 2023) Pernegger, H.; Allport, P.; Berlea, D. V.; Birman, A.; Bortoletto, D.; Denizli, Haluk
    Depleted Monolithic Active Pixel Sensor (DMAPS) sensors developed in the Tower Semiconductor 180 nm CMOS imaging process have been designed in the context of the ATLAS ITk upgrade Phase-II at the HL-LHC and for future collider experiments. The "MALTA-Czochralski (MALTA-Cz)" full size DMAPS sensor has been developed with the goal to demonstrate a radiation hard, thin CMOS sensor with high granularity, high hit-rate capability, fast response time and superior radiation tolerance. The design targets radiation hardness of > 10(15) (1 MeV) n(eq)/cm(2) and 100 Mrad TID. The sensor shall operate as tracking sensor with a spatial resolution of approximate to 10 mu m and be able to cope with hit rates in excess of 100 MHz/cm(2) at the LHC bunch crossing frequency of 40 MHz. The 512 x 512 pixel sensor uses small collection electrodes (3.5 mu m) to minimize capacitance. The small pixel size (36.4 x 36.4 mu m(2)) provides high spatial resolution. Its asynchronous readout architecture is designed for high hit-rates and fast time response in triggered and trigger-less detector applications. The readout architecture is designed to stream all hit data to the multi-channel output which allows an off-sensor trigger formation and the use of hit-time information for event tagging.The sensor manufacturing has been optimised through process adaptation and special implant designs to allow the manufacturing of small electrode DMAPS on thick high-resistivity p-type Czochralski substrate. The special processing ensures excellent charge collection and charge particle detection efficiency even after a high level of radiation. Furthermore the special implant design and use of a Czochralski substrate improves the sensor's time resolution. This paper presents a summary of sensor design optimisation through process and implant choices and TCAD simulation to model the signal response. Beam and laboratory test results on unirradiated and irradiated sensors have shown excellent detection efficiency after a dose of 2 x 10(15) 1 MeV n(eq)/cm(2). The time resolution of the sensor is measured to be sigma = 2 ns.
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    Radiation hardness of MALTA2, a monolithic active pixel sensor for tracking applications
    (IEEE-Inst Electrical Electronics Engineers Inc., 2023) Denizli, Haluk; Berlea, D. V.; Allport, P.; Tortajada, I. Asensi; Bortoletto, D; Buttar, C.
    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 1 x 10(15) 1 MeVn(eq)/cm(2) 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.
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    Timing performance of radiation hard MALTA monolithic pixel sensors
    (IOP Publishing Ltd, 2023) Gustavino, G.; Allport, P.; Asensi, I.; Berlea, D. V.; Bortoletto, D.; Denizli, Haluk; Oyulmaz, Kaan Yüksel
    The MALTA family of Depleted Monolithic Active Pixel Sensor (DMAPS) produced in Tower 180 nm CMOS technology targets radiation hard applications for the HL-LHC and beyond. Several process modifications and front-end improvements have resulted in radiation hardness up to 2 x 10(15) 1 MeV n(eq)/cm(2) and time resolution below 2 ns, with uniform charge collection efficiency across the pixel of size 36.4 x 36.4 mu m(2) with a 3 mu m(2) electrode size. The MALTA2 demonstrator produced in 2021 on high-resistivity epitaxial silicon and on Czochralski substrates implements a new cascoded front-end that reduces the RTS noise and has a higher gain. This contribution shows results from MALTA2 on timing resolution at the nanosecond level from the CERN SPS test-beam campaign of 2021.