Characterisation Of The Radiation Tolerance Of Hv-Cmos Sensors Using The Transient Current Technique

A novel pixel sensor based on High-Voltage CMOS (HV-CMOS) technology is being proposed for the tracker upgrade of ATLAS for the High-Luminosity LHC. Due to the proximity to the proton-proton collisions region, the sensors will have to cope with an extremely harsh radiation environment. Therefore, their performance needs to be tested with increasing values of received dose. In this context, the characterisation of the depletion region of proton irradiated prototype sensors with different resistivities is presented, using the Transient Current Technique (TCT). In order to compare the effects given by irradiation with particles of different energies, the sensors were irradiated with fluences of up to 1.5 x 10(15) 1 MeV n(eq)/cm(2) with proton beams of 16.7 MeV momentum at the Bern Cyclotron and 24 GeV momentum at the CERN Proton Synchrotron. In both cases, a strong increase of the depletion region due to initial acceptor removal has been observed at small fluences.