Active pixel sensors with enhanced pixel-level analog and digital functionalities in a 2-tier 3D CMOS technology

This paper presents the results of the characterization of novel CMOS active pixel sensors that take advantage of 3D integration to increase the electronic functions in the pixel readout cells. These sensors were designed in the frame of an R&D program targeting applications to high energy physics experiments at advanced particle accelerators. They were fabricated with the Tezzaron/GlobalFoundries 3D process, which makes it possible to build two-tier integrated circuits by the face-to-face bonding of two 130 nm CMOS wafers. High-density “via middle” TSVs and small-pitch Cu-Cu interconnections between tiers make this process suitable for aggressive mixed-signal circuit design.