Abstract
Due to radiation hardness requirements, 3D detectors are the best candidate technology for the innermost tracking layers at the High Luminosity LHC (HL-LHC) as well as for radiation monitoring in long space missions. In the framework of the project "Three-dimensional Low-Voltage Silicon Detectors" funded by ESA, SINTEF Minalab has developed novel full 3D detectors with slim and active edges. Functional tests to measure the charge collection efficiency after irradiation at the fluences expected at the HL-LHC cannot be accurately measured using the current readout chips due to their limited radiation tolerance. As an alternative, small-size 3D diodes connected to discrete read-out channels can be used. This study is aimed at investigating the performance of 3D sensors of different inter-electrode spacing which were designed and fabricated by SINTEF Minalab (Oslo, Norway). At the conferece, we will recall the main design and technological aspects for these sensors, and report selected results from their characterization with IR laser after neutron irradiation up to 2 x 10e16 neutron equivalent /cm^2.