Evaluation of HPK n + - p planar pixel sensors for the CMS Phase-2 upgrade

Journal Article · 08 May 2023 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

DOI: https://doi.org/10.1016/j.nima.2023.168326 · OSTI ID:2341418

Adam, W. ^[1]; Bergauer, T.; Bloch, D.; Dragicevic, M.; Frühwirth, R.; Hinger, V.; Steininger, H.; Beaumont, W.; Di Croce, D.; Janssen, X.

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1. University of Colorado Boulder

To cope with the challenging environment of the planned high luminosity upgrade of the Large Hadron Collider (HL-LHC), scheduled to start operation in 2029, CMS will replace its entire tracking system. The requirements for the tracker are largely determined by the long operation time of 10 years with an instantaneous peak luminosity of up to 7.5 × 10³⁴ cm^–2 s^–1 in the ultimate performance scenario. Depending on the radial distance from the interaction point, the silicon sensors will receive a particle fluence corresponding to a non-ionizing energy loss of up to $$\Phi_{\text {eq}}$$ = 3.5 × 10¹⁶ cm^–2. Here this paper focuses on planar pixel sensor design and qualification up to a fluence of $$\Phi_{\text {eq}}$$ = 1.4 × 10¹⁶ cm^–2. For the development of appropriate planar pixel sensors an R&D program was initiated, which includes $n^+ -p$ sensors on 150 mm (6”) wafers with an active thickness of 150 μm with pixel sizes of 100 × 25 μm² and 50 × 50 μm² manufactured by Hamamatsu. Single chip modules with ROC4Sens and RD53A readout chips were made. Irradiation with protons and neutrons, as well was an extensive test beam campaign at DESY were carried out. This paper presents the investigation of various assemblies mainly with ROC4Sens readout chips. It demonstrates that multiple designs fulfill the requirements in terms of breakdown voltage, leakage current and efficiency. The single point resolution for 50 × 50 μm² pixels is measured as 4.0 μm for non-irradiated samples, and 6.3 μm after irradiation to $$\Phi_{\text {eq}}$$ = 7.2 × 10¹⁵ cm^–2.

• Research Organization: Univ. of Colorado, Boulder, CO (United States)
• Sponsoring Organization: USDOE
• Contributing Organization: Tracker Group of the CMS Collaboration
• Grant/Contract Number: SC0010005
• OSTI ID: 2341418
• Alternate ID(s): OSTI ID: 2477969; OSTI ID: 2202842
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Journal Name: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment Vol. 1053; ISSN 0168-9002
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English