CMOS Pixel Sensors are making steady progress towards the specifications of the ILD vertex detector. Recent developments are summarised, which show that these devices are close to comply with all major requirements, in particular the read-out speed n
eeded to cope with the beam related background. This achievement is grounded on the double- sided ladder concept, which allows combining signals generated by a single particle in two different sensors, one devoted to spatial resolution and the other to time stamp, both assembled on the same mechanical support. The status of the development is overviewed as well as the plans to finalise it using an advanced CMOS process.
Swift, high resolution CMOS pixel sensors are being developed for the ILC vertex detector, aiming to allow approaching the interaction point very closely. A major issue is the time resolution of the sensors needed to deal with the high occupancy gene
rated by the beam related background. A 128x576 pixel sensor providing digitised outputs at a read-out time of 92.5 us, was fabricated in 2008 within the EU project EUDET, and tested with charged particles at the CERN-SPS. Its prominent performances in terms of noise, detection efficiency versus fake hit rate, spatial resolution and radiation tolerance are overviewed. They validate the sensor architecture.
The impact of the incoherent electron-positron pairs from beamstrahlung on the occupancy of the vertex detector (VXD) for the International Large Detector concept (ILD) has been studied, based on the standard ILD simulation tools. The occupancy was e
valuated for two substantially different sensor technology in order to estimate the importance of the latter. The influence of an anti-DID field removing backscattered electrons has also been studied.
