Radiation-Hard Silicon Strip Sensors for the ATLAS Phase-2 Upgrade

The ATLAS upgrade for HL-LHC operation includes the installation of an entirely new all-silicon Inner Tracker (ITk). The silicon strip region comprises $165\,\mathrm{m}^2$ of instrumented area, made possible by mass production of silicon strip sensors. This area is covered in a nearly hermetic way. Multiple sensor shapes are utilized: square sensors in the barrel part, and skewed trapezoidal sensors with curved edges to provide a continuous coverage of the disc surface in the endcap part of a detector. As a result, there are $8$ different strip sensor types in the system. They all feature AC-coupled n${}^+$-in-p strips with polysilicon biasing, developed to withstand the total fluence of $1.6\cdot 10^{15}\, \mathrm{n_{eq}/cm^2}$ and the total ionizing dose of $66\, \mathrm{Mrad}$. Following many years of R&D and $4$ prototype submissions and evaluations, the project transitioned into pre-production, where $5\,$% of the total volume is produced in all $8$ designs. In this contribution we will summarize the results obtained for the latest prototype sensors ATLAS$17$LS, a long-strip type sensor for the barrel part, the properties of which are expected to be comparable with the pre-production sensors.