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 4th 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⋅1014 and 5⋅1015 1-MeV-neq/cm2. The sensors were glued to ATLAS FE-I4 pixel readout chips and measured at the CERN SPS H8 beamline using the FE-I4 beam telescope. Results for all fluences are very encouraging with all hit efficiencies being better than 97% for bias voltages of 85V. The sample irradiated to a fluence of 1⋅1015 neq/cm2 - a relevant value for a large volume of the upgraded tracker - exhibited 99.7% average hit efficiency. The results give strong evidence for the radiation tolerance of HV-CMOS sensors and their suitability as sensors for the experimental HL-LHC upgrades and future large-area silicon-based tracking detectors in high-radiation environments.
@article{arxiv.1611.02669,
title = {Testbeam results of irradiated ams H18 HV-CMOS pixel sensor prototypes},
author = {M. Benoit and S. Braccini and G. Casse and H. Chen and K. Chen and F. A. Di Bello and D. Ferrere and T. Golling and S. Gonzalez-Sevilla and G. Iacobucci and M. Kiehn and F. Lanni and H. Liu and L. Meng and C. Merlassino and A. Miucci and D. Muenstermann and M. Nessi and H. Okawa and I. Peric and M. Rimoldi and B. Ristic and M. Vicente Barrero Pinto and J. Vossebeld and M. Weber and T. Weston and W. Wu and L. Xu and E. Zaffaroni},
journal= {arXiv preprint arXiv:1611.02669},
year = {2018}
}