Capacitive Deep Trench Isolation-Based CCD-on-CMOS Image Sensor Sensitivity to Total Ionizing Dose

Abstract

This work presents a new type of Charge Coupled Device (CCD) manufactured using a CMOS process and featuring Capacitive Deep Trench Isolation (CDTI). The device is used in a Multi-Pinned Phase mode (MPP) enabling almost constant oxide interface passivation. Flatband shift, Dark current and Charge Transfer Inefficiency (CTI) induced by Total Ionizing Dose (TID) are investigated. Despite the increase of interface states, results show that dark current can be efficiently mitigated by use of short charge transfer duration, avoiding full interface depletion and free charge generation. It is further shown that trapping by interface states is only lightly affecting CTI as the Buried Channel keeps electrons far from interfaces. Finally, a clear correlation on flatband shift with Full Well Charge (FWC) reduction is established.