3D detectors-state of the art

3D detectors, with electrodes penetrating through the silicon substrate were fabricated, and characteristics such as speed, radiation hardness and edge sensitivity were studied. The signal shape was observed using a fast, low-noise transimpedance amplifier. The rise time of the signal obtained for a minimum ionizing particle was faster than 3 ns at room temperature. This is in agreement with earlier calculations of 3D sensors that showed the charge collection time to be between 1 and 2 ns. Similar tests were performed on detectors after exposure to proton beams with doses ( 1.8 × 10¹⁵ 24 GeV protons / cm² ) equivalent to those expected after 10 years at the innermost layers of the ATLAS experiment at the large hadron collider (LHC). Edge sensitivity was measured at the advanced light source at Lawrence Berkeley Laboratory, using an X-ray micro-beam. The detectors were measured to be efficient up to less than 10 μ m from their physical edges. Results presented in this paper confirm the suitability of this design for possible future LHC upgrades, where the integrated fluence is expected to increase by a factor of 10. Moreover, their speed characteristics have placed them as potential candidates for the CERN linear collider (CLIC) where the bunch-crossing separation can be as short as 1.2 ns.