Speaker
Description
10 years ago the journey of 3D sensors in CMS began with a test beam at the Fermilab Test Beam Facility. The first FBK prototype sensors featuring pixel cells with 100 x 150 $\mu m^2$, same as the current CMS pixel detector, were bump bonded to the PSI46digv2 readout chip and measured on beam. Performance well beyond the best expectations were observed and paved the way to the development of small pitch sensors with 25 x 100 and 50 x 50 $\mu m^2$ pixel cells. Continuous test beam campaigns and irradiation campaigns were performed over the years following the developments of the phase-2 readout chip by the RD53 collaboration, for both ATLAS and CMS next generation pixel detectors. The first prototype, named RD53A, became available in 2018 and featured three different analogue front-ends. Following extensive test beam and laboratory measurements the CMS collaboration chose the linear front-end, that was implemented in the second prototype, named CROCv1, which became available in 2021. The sensors production process evolved in parallel, with the aim of mitigating the insurgence of noisy channels that was observed after irradiation and operation at high bias voltages. In 2022 CMS officially decided to employ 3D sensors with rectangular pixel cells in the innermost layer of the barrel section of the phase-2 pixel detector. This presentation will show highlights from this 10 years journey and will briefly describe the production status.