Impact amplification with CMOS pixel sensors – APICS

According to detector R&D roadmaps established by the high-energy physics community, Monolithic active pixel sensors fabricated in a CMOS technology (MAPS) are foreseen to play a major role as detection devices in a large number of future collider experiment projects. Still current MAPS do not match a number of expected performance required by the science. The APICS project aims at closing this gap by introducing a mild amplification of the primary charges in the sensitive layer.
On the one hand, a larger raw pixel signal compared to current sensors will require no or very limited analogue electronic treatment, shrinking drastically the pixel size and the power dissipation. Such pixels will then be suited to reach the best position resolution required for inner detection layers or the lowest power required for large tracking replacing the traditional gaz volumes. On the other hand, a large and faster signal will allow reaching time resolution useful for particle identification through the time of flight technique.
CPPM has been involved in the development of the first MAPS featuring a shallow layer with specific doping to ensure depletion of the sensitive volume. IPHC has a long-standing expertise in simulating the sensitive volume of MAPS and fabricating small matrix prototypes dedicated to R&D. ICUBE has already designed photo-detectors based on avalanche in silicon. All labs join in APICS to tackle the challenge of simulating, designing and characterizing a new charge collection node in MAPS, adapted to low primary signal gain.
APICS deliverables consist of small pixel matrix prototypes demonstrating the amplification at the desired level and allowing to investigate the limits of the followed strategy in terms of operational conditions (temperature, ionizing and non-ionizing radiation). A mainstream CMOS technology will be employed to facilitate later the transfer of the project findings to existing large matrix read-out architecture and reach quickly application-ready sensors.