The active DEPFET pixel sensor for future e+e- linear collider experiments

The e⁺e^- linear collider physics program sets highly demanding requirements on the accurate determination of charged particle trajectories close to the interaction point. A new generation of DEPFET active pixel sensors with ∼25 μm pixel size has been developed to meet the requirements in point measurement resolution and multiple track separation. The paper presents the design and technology of the new linear MOS-type DEPFET sensors and gives a comparison between the previously simulated properties with the actually measured characteristics. The charge storage capability of the DEPFET pixels enables a read-out scheme where only one row is active at a time. The resulting low power consumption of the array together with the low noise operation of the devices allow the design of extremely thin sensors needed for efficient determination of secondary and tertiary vertices. A module concept and a technology for the production of ultra-thin fully depleted DEPFET sensors will be presented. The technology makes efficient production of thin wafer-scale pixel arrays and safe assembling of the sensor modules into a vertex detector possible.