3D Silicon Detectors

Twenty years after their introduction by Sherwood Parker and collaborators, 3D silicon detectors have reached their maturity. The ATLAS IBLrepresents an important milestone: it is the first application of 3D technology to a High Energy Physics experiment,and it has demonstrated the feasibility of a medium volume production with a relatively good yield. In spite of this significant achievement, the future Phase 2 upgrades of experiments at the HL-LHCare setting very challenging demands in terms of smallerpixel size, reduced sensor thickness, and ultra-high radiation tolerance, calling for the development of a new generation of 3D sensors. This paperreviews the state of the art in 3D detectors, and addresses the next directions of their development in view of the application to HL-LHC. The main designand technological issues are reported, as well as preliminaryresults from TCAD simulations.