Hardening Techniques for Image Sensors

Abstract

Dr. Vincent Goiffon, ISAE-SUPAERO, University of Toulouse, will provide an overview of the main radiation-induced degradations in solid state image sensors and present mitigation techniques to improve their radiation hardness and enable their use in harsh radiation environments. Among the wide variety of radiation effects relevant for pixel arrays and detectors, radiation-induced leakage currents in PN junctions are by far the main factor limiting the performances of these mixed signal integrated circuits when exposed to fields of high energy particles. How Total Ionizing Dose affects these leakages and how design and process optimizations can reduce the dark current in irradiated sensors will be discussed. What can enhance or reduce the sensitivity of an image sensor to more specific effects such as displacement damage and radiation induced random telegraph signal will also be addressed. The presentation will primarily focus on the CMOS Image Sensor technology, but will also explore the applicability of the presented concepts to other solid state image sensor technologies, as well as the similarities with other leakage sensitive devices such as DRAMs. This presentation will conclude by an overview of the relevant pixel radiation hardening techniques to use depending on the application requirements: from Earth observation space instruments to the exploration of the Jovian system and nuclear fusion instrumentation.