Description
The ATLAS upgrade for HL-LHC operations includes an entirely new all-silicon Inner Tracker (ITk). The silicon strip region comprises 165 m$^2$ of instrumented area, made possible by mass production of silicon strip sensors. This area is covered in a nearly hermetic way. Slim edge technology is used to minimize inefficiency gaps between adjacent devices. Multiple shapes with curved edges are utilized to provide a continuous coverage of the disc surface in the endcap. 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 for 1.6e15 neq/cm$^2$ fluence and 66 Mrad dose.
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 10 designs. Deliveries are scheduled for early 2020. We will report on the evaluation program, test results, and experience with the pre-production sensors.
