Front-end performance and charge collection properties of heavily irradiated DNW MAPS

Deep N-well (DNW) CMOS monolithic active pixel sensors (MAPS) fabricated in a 130 nm technology have been exposed to γ-rays up to an integrated dose of about 10 Mrad and subjected to a 100°/168 h annealing cycle. Device tolerance to total ionizing dose has been evaluated by monitoring the change in charge sensitivity, noise and charge collection properties after each step of the irradiation and annealing campaign. Damage mechanisms and their relation to front-end architecture and sensor features are thoroughly discussed by comparing the response to ionizing radiation of different test structures and based on radiation induced degradation models in single MOS transistors.