3D silicon pixel detectors for the High Luminosity LHC
3D silicon pixel detectors have been investigated as radiation hard candidates for the innermost layers of the HL LHC upgrade of the ATLAS pixel detector. 3D detectors are already in use today in the ATLAS IBL and AFP experiments. These are based on 50 x 250 mm2 large pixels connected to the FE I4 readout chip. Detectors of this generation were irradiated to HL LHC fluences and demonstrated excellent radiation hardness with operational voltages as low as 180 V and power dissipation of 12 15 mW/cm2 at a fluence of about 1016 neq/cm2, measured at 25degC. Moreover, to cope with the higher occupancies expected at the HL LHC, a first run of a new generation of 3D detectors designed for the HL LHC was produced at CNM with small pixel sizes of 50 x 50 and 25 x 100 mm2, matched to the FE I4 chip. They demonstrated a good performance in the laboratory and in beam tests with hit efficiencies of about 97% at already 1 2 V before irradiation.