Achievements and perspectives of CMOS pixel sensors for charged particle tracking

Main achievements of more than one decade of CMOS pixel sensor R&D for charged particle tracking are reviewed in this paper, together with the goals driving present R&D activities, i.e. read-out speed and radiation tolerance. A fast read-out sensor developed for the EUDET beam telescope and the STAR vertex detector is described as well as its first test results. Preliminary results are also provided on non-ionising radiation tolerance improvements offered by CMOS processes featuring a depleted epitaxial layer. Finally, the recent access to 3D Integration Technologies, which alleviate most essential CMOS sensorʹs limitations, has translated into 2- and 3-tier sensor designs, to be fabricated in Spring 2009. Their main design features and expected performances are reviewed.