Monolithic active pixel sensor

A monolithic active pixel sensor (MAPS) is a type of CMOS active-pixel sensor optimized for detection of the ionizing radiation rather than the visible light. In MAPS, both the sensor and the readout electronics are integrated onto the same silicon substrate. The term monolithic is used to distinguish^[1] CMOS APS from hybrid pixel detectors in which the sensor and the readout electronics are on two different substrates, normally connected by bump-bonding.

MAPS-based detectors offer exceptional spatial resolution at low noise, power consumption, material budget, and cost. Their most significant application lies in high-energy physics experiments, particularly those that require coverage of large areas and moderate radiation hardness, such as the ALICE experiment^[2] at the CERN Large Hadron Collider.