Overview of the ATLAS Insertable B-Layer (IBL) Project

The upgrade of the present ATLAS detector with a new layer of hybrid pixel detectors constitutes\nthe first improvement of the tracking system for operation at high luminosity LHC. The new subdetector, called Insertable B-Layer (IBL), is currently under construction and will be installed\nbetween the existing pixel detector and a new beam pipe of smaller diameter. The increased\nradiation, pixel occupancy as well as the more stringent material budget and space requirements\ndemanded the development of several new technologies for the IBL.\nA novel ~4 $\mathrm{cm}^2$ Front-End chip (FE-I4) in 130 nm CMOS technology, able to cope with 250\nMRad total ionizing dose, was designed. To reduce the material budget the Front-Ends are thinned down to 150 m m and mechanical support structures which are made of new composite materials with $\mathrm{CO}_2$ based cooling tubes are deployed. Two different slim edge sensor technologies are used for the IBL: planar n-in-n sensors and, for the first time, innovative 3D sensors.\nAfter a short overview of the IBL project the current status of the IBL production is presented\nwith a focus on the quality assurance at wafer, module and stave levels. Particular emphasis\nis put on the results of the FE-I4 wafer probing that has been successfully completed. Final\nresults including the yield and distributions of calibration values and important chip parameters\nare shown for 2580 Front-Ends tested.